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10.1371/journal.pone.0309387
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Public welfare donation, rent sharing, and income gap within enterprises
Public welfare donation in the enterprises
Chen Jiantao Data curation Methodology Writing – original draft Writing – review & editing 1
https://orcid.org/0009-0004-9352-052X
Luo Xiang Methodology Writing – original draft 2 *
Wang Xiao Data curation Writing – review & editing 3
1 School of Economics and Management, Southwest Petroleum University, Chengdu City, Sichuan Province, China
2 School of Economics and Management, Southwest Jiaotong University, Chengdu City, Sichuan Province, China
3 College of Economics & Management, Mianyang Teachers’ College, Mianyang City, Sichuan Province, China
Ahmad Yasir Editor
National University of Sciences and Technology, PAKISTAN
Competing Interests: The authors have declared that no competing interests exist.

* E-mail: Flytigerluo@163.com
5 9 2024
2024
19 9 e03093871 1 2023
10 8 2024
© 2024 Chen et al
2024
Chen et al
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This study utilizes data from A-share listed companies between 2011 and 2020 to empirically investigate the impact and mechanism of public welfare donations on the internal income gap of enterprises. The research findings indicate that public welfare donations significantly increase the per capita salary of management, while their impact on the per capita salary of ordinary employees is not significant, thus leading to an expansion of the internal income gap within enterprises. The results from mechanism testing reveal that the income tax benefits resulting from charitable donations and the rise in corporate operating income have contributed to an increase in excess rent shared by enterprises and employees. Due to a stronger bargaining power, management shares more excess rents, thereby widening the income gap within the enterprise. Heterogeneity analysis demonstrates that public welfare donations have a greater impact on the internal income gap of non-state-owned enterprises; however, limiting executive compensation and enhancing employees’ bargaining power can mitigate this widening effect caused by public welfare donations on enterprise’s internal income gap. The research value of this study is threefold. Firstly, there is a scarcity of studies on the impact of public welfare donations on the income gap within enterprises, and this study contributes to enriching the research in this area. Secondly, this paper examines the effect of tax incentives for public welfare donations on the internal income gap of enterprises, thereby deepening the research on the impact of tax reduction and fee reduction, as well as expanding our understanding of corporate income tax preferential policies. Thirdly, it offers insights into improving enterprise compensation systems and enhancing corporate governance. Senior executives can potentially allocate more excess rent through their strong bargaining power. If their compensation remains unrestricted, it may lead to a widening internal income gap and negatively affect company operational efficiency.

Mianyang Social Science Key Research Base - Sichuan Modern Circulation Economy Research Center, Tianfu College, Southwest University of Finance and Economics XDLTJJ2023YB11 Wang Xiao The authors received funding support by Mianyang Social Science Key Research Base - Sichuan Modern Circulation Economy Research Center, Tianfu College, Southwest University of Finance and Economics (XDLTJJ2023YB11) for this work. Specific grant numbers: XDLTJJ2023YB11 Initials of authors who received each award:X W Full names of commercial companies that funded the study or authors: Mianyang Social Science Key Research Base - Sichuan Modern Circulation Economy Research Center, Tianfu College, Southwest University of Finance and Economics Initials of authors who received salary or other funding from commercial companies:X W URLs to sponsors’ websites: https://mce.tfswufe.edu.cn/index.htm The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Data AvailabilityAll data files are available from the CSMARS database: https://cn.gtadata.com/.
Data Availability

All data files are available from the CSMARS database: https://cn.gtadata.com/.
==== Body
pmcIntroduction

Corporate social responsibility encompasses various aspects, including economic, legal, ethical, and charitable responsibilities [1]. Public welfare donations fall under the category of charitable responsibility and are considered a crucial civic behavior for enterprises, representing the highest form of corporate social responsibility [2]. The impact of public welfare donations on corporate social responsibility is reflected in: firstly, through public welfare donations, companies can improve their reputation, social status, third-party organization rankings, and fulfill their economic responsibilities [3]; Secondly, public welfare donations can enable enterprises to obtain legal and compliance recognition from external and internal stakeholders [4,5], fulfilling legal and ethical responsibilities; Finally, public welfare donations fulfill their charitable responsibilities, As the main means of three distributions, public welfare donations can be of great significance in regulating residents’ income gap, alleviating social conflicts, and promoting fairness and justice. However, the role of public welfare donations in the internal income distribution of enterprises is rarely studied. As an important part of the income distribution of the whole society, the internal income distribution of the company will have a significant impact on the income distribution pattern of the whole society [6]. The existing research results show that the income gap within Chinese enterprises is gradually increasing, and its contribution to the overall social income gap has reached 33% [7,8]. In this context, exploring the impact of public welfare donations on the internal income gap of enterprises and Countermeasures to promote the fairness of domestic income distribution and achieve common prosperity in China is of positive significance.

This study aims to analyze the impact and mechanism of public welfare donations on enterprise income distribution from the perspective of the income gap between the company’s management and ordinary employees. The management of the company in this study refers to the members of the board of directors, the members of the supervisory board and the senior management of the company; ordinary employees refer to the members of the company other than the management. Theoretically, enterprises get two types of excess rents, namely tax preference and operating performance, due to public welfare donations. Article 9 of the Enterprise Income Tax Law of the People’s Republic of China: The portion of public welfare donation expenses incurred by enterprises within 12% of the total annual profit is allowed to be deducted when calculating taxable income. Due to the different bargaining power of the internal management and ordinary employees, the sharing degree of the company’s rent will also be different, which may lead to changes in the internal income gap of enterprises [9,10]. Then, what impact will public welfare donations have on the income of management and ordinary employees? Will it widen or narrow the income gap within enterprises? This study will empirically test and analyze the above problems based on the micro data of A-share listed companies from 2011 to 2020.

The main contributions of this study are as follows: first, it enriches the research on the impact of public welfare donations on the income gap. Most of the existing literature focuses on the positive role of public welfare donations in the three distributions, and few studies focus on the impact of public welfare donations on the income gap within enterprises. Second, it expands the research on the effect of preferential policies of enterprise income tax. The existing literature mainly focuses on the positive effects brought by the preferential policies of enterprise income tax. This study studies the effect of the income tax preferential policies and pre-tax tax deduction of public welfare donations on the internal income gap of enterprises and deepens the research on the effect of tax reduction and fee reduction. Third, it provides some inspiration for improving the compensation system of enterprises and improving the level of corporate governance. Executives can allocate more excess rent through strong bargaining power. If their remuneration is not constrained, it will cause the income gap within the enterprise to widen and affect the operating efficiency of the company.

Theoretical analysis and research hypothesis

Rent sharing refers to the process in which enterprises pay employees excessive remuneration due to the improvement of business performance, and the result is an increase in employees’ average remuneration [11]. In the modern corporate system, company owners consider the growth of business performance as the main indicator for assessing management. In order to maximize their own interests, the management of the enterprise may request to share the enterprise rent [12]. Meanwhile, with the growth of business performance, ordinary employees will also demand to share rent and increase salaries. Otherwise, it will seriously reduce employees’ labor enthusiasm and be detrimental to business operations [13]. So, when public welfare donations promote the improvement of business performance, employees (including management and ordinary employees) will share the company’s rent.

Public welfare donations increase the rent shared by enterprises and employees in two ways: first, the Pre-tax deduction policy for public welfare donations reduces the tax burden of enterprises, improves the after-tax profits of the company, and thus increases the rent shared by enterprises and employees [14]. Second, public welfare donations can bring many benefits to enterprises while fulfilling their social responsibilities. For example, public welfare donations can receive a good “advertising effect”, which can not only reduce the advertising expenditure of enterprises but also improve the brand awareness of enterprises [15]. It can improve the competitive environment of enterprises, facilitate enterprises to obtain resources from external stakeholders [16], significantly reduce the negative impact of adverse factors on the reputation of enterprises, improve core competitiveness and improve financial performance [17], Increase the rent shared by enterprises and employees.

The rent-sharing theory believes that the level of rent-sharing of a company determines the income gap among employees [18]. The bargaining theory points out that the level of salary is determined by the enterprise and employees through bargaining, and is affected by the bargaining power of both parties. Similarly, the amount of rent shared by employees with different bargaining power within the company will also be different, which will lead to the widening of the income gap within the enterprise [19]. Employees of the company can be divided into management and ordinary employees according to their quality. China has a large labor force population base, fierce market competition for ordinary employees, and relatively small supply elasticity; However, as senior managers have higher requirements for academic qualifications, skills, and experience, the number of them is relatively small, and the supply elasticity is relatively large, senior managers can negotiate for high salaries. In addition, managers have the motivation and ability to determine the distribution rules of remuneration and interfere with the remuneration of ordinary employees. When the total amount of remuneration that an enterprise can pay is certain, there is a trade-off relationship between the remuneration of ordinary employees and management. Therefore, this study believes that the bargaining power of management is stronger than that of ordinary employees, so it often occupies an advantage in rent sharing, which ultimately leads to the widening income gap between management and ordinary employees.

To sum up, this study assumes that compared with the per capita remuneration of ordinary employees, the positive impact of the company’s public welfare donations on the per capita remuneration of management will be more significant. At the same time, with the increase in corporate public welfare donations, the internal income gap of the company is increasing.

Research design

Sample data source

This study selects A-share listed companies from 2011 to 2020 as the research sample. The sample was screened as follows: (1) Financial and insurance listed companies were excluded; (2) Excluding ST and *ST listed companies; (3) Exclude listed companies whose per capita remuneration of management is lower than that of ordinary employees, because the amount of management salary disclosed by such companies may only include allowances; (4) The reason for excluding listed companies with negative profits is that such companies cannot examine the tax reduction effect of public welfare donations; (5) Remove samples with incomplete key variables. The data in this study are all from CSMAR. In addition, we also performed tailing on all continuous variables at the upper and lower 1% levels. Finally, 16677 effective samples were obtained.

Research variables

Explained variable. Per capita remuneration of management (GWAGE). The management studied in this study includes members of the board of directors, members of the board of supervisors, and senior managers [20]. The salary of management personnel mainly includes fixed salary and performance bonus. The scope and proportion of equity payments for Chinese listed companies are relatively small. This study did not consider equity incentives when calculating the average employee salary, but controlled for the management’s shareholding ratio in the model. The average remuneration of the management is calculated according to the total annual remuneration and the number of directors, supervisors, and senior executives disclosed in the annual report of the listed company. Among them, the management scale refers to the “total number of directors, supervisors and senior executives” minus the “number of independent directors” and the “number of directors, supervisors and senior executives who are not paid".

Per capita salary of ordinary employees (YWAGE). The ordinary employees studied in this study are employees of enterprises other than directors, supervisors, and senior managers [21]. The salary of ordinary employees mainly includes fixed salary and performance bonus. The total salary of ordinary employees is calculated by subtracting the total annual salary of directors, supervisors, and senior managers from the "cash paid to and for employees" in the cash flow statement, and then divided by the number of ordinary employees to get the average salary of ordinary employees.

Intra-enterprise income gap(GAP). The salary data of all employees in the enterprise is difficult to obtain, but the salary gap between the management and ordinary employees of listed companies can be used to replace the income gap between the rich and ordinary. Therefore, this study refers to the methods of Card et al. [10]and uses the salary gap between the management and ordinary employees to represent the income gap within the enterprise. The specific calculation method is as follows: the difference between the per capita salary of the management of the enterprise minus the per capita salary of the ordinary employees of the enterprise is taken as the logarithm.

Main explanatory variables. Public welfare donation. According to China’s Public Welfare Donation Law, public welfare donations only refer to donations made by enterprises through social organizations, organizations, government agencies, etc. as stipulated by law. This concept is mainly reflected in tax laws. The public welfare donation data in this study comes from the details of "donation expenses", "charitable donation expenses", and "public welfare donation expenses" under the "non operating expenses" item in the notes of listed companies’ reports in the CSMAR, which are manually organized and processed. Referring to the method of Zhang et al. [22], the donation amount is logarithmically measured to measure the Donation variable.

Control variable. Referring to previous relevant studies[11,20], this study comprehensively considers the possible impact of various factors on the income gap of employees within the enterprise and selects a series of relevant variables that affect the remuneration of senior executives and ordinary employees, including the size of the enterprise (SIZE), the integration of two positions (DUAL), the net cash flow from operations (OCF), the asset-liability ratio (LEV), the nature of the enterprise (SOE), the time of listing (AGE), the Growth rate of operating revenue (GROWTH), the shareholding proportion of the largest shareholder (TOP) and shareholding proportion of management (MSHARE). As shown in Table 1.

10.1371/journal.pone.0309387.t001 Table 1 Variable definition table.

Main variable	Variable name	Variable symbol	Variable measurement method	
Explained variables
	Internal income gap	GAP	The logarithm of the absolute value of the difference between the per capita remuneration of the management and that of ordinary employees	
Management income	GWAGE	Per capita remuneration of management, as defined in the text	
Income of ordinary employees	YWAGE	Per capita salary of ordinary employees, as defined in the text	
Explain
variables	Public welfare donation expenditure	Donation	See the text for the definition of enterprise public welfare donation expenditure	
Control
variables	Enterprise scale	SIZE	The logarithm of total assets at the end of the period	
Financial leverage	LEV	Total liabilities / total assets	
Enterprise nature	SOE	The value of state-owned enterprises is 1, and the value of non-state-owned enterprises is 0	
Years of listing	AGE	Time from research year to market year	
Development speed	GROWTH	The growth rate of operating revenue	
The shareholding proportion of the largest shareholder	TOP	The shareholding proportion of the largest shareholder (%)	
Proportion of independent directors	INBOARD	The proportion of independent directors on the board of directors (%)	
Duality	DUAL	Whether the chairman of the board concurrently serves as the general manager = 1, otherwise = 0	
The shareholding ratio of management	MSHARE	The shareholding ratio of management (%)	
Cash flow	OCF	Net cash flow from operating activities at the end of the period / total assets at the end of the period	
Other
variables	Tax policy	POLICY	If the year is less than 2017, the value is 0; otherwise, it is 1.	
Actual tax negative rate of enterprise	TAXR	Total income tax expense/profit	
Enterprise performance	ROE	Net profit / net assets	

Research model design. To test the impact of public welfare donations (Donation) on the per capita remuneration of management (GWAGE), model (1) is constructed as follows: GWAGEi,t=α0+α1Donationi,t+α2SIZEi,t+α3LEVi,t+α4SOEi,t+α5AGEi,t+α6GROWTHi,t+α7TOPi,t+α8INBOARDi,t+α9DUALi,t+α10MSHAREi,t+α11OCFi,t+YEAR+IND+εi,t (1)

To test the impact of public welfare donations (Donation) on the per capita salary of ordinary employees(YWAGE), model (2) is constructed as follows: YWAGEi,t=α0+α1Donationi,t+α2SIZEi,t+α3LEVi,t+α4SOEi,t+α5AGEi,t+α6GROWTHi,t+α7TOPi,t+α8INBOARDi,t+α9DUALi,t+α10MSHAREi,t+α11OCFi,t+YEAR+IND+εi,t (2)

To test the impact of public welfare donations (Donation) on the internal income gap of enterprises (GAP), a model (3) is constructed as follows: GAPi,t=α0+α1Donationi,t+α2SIZEi,t+α3LEVi,t+α4SOEi,t+α5AGEi,t+α6GROWTHi,t+α7TOPi,t+α8INBOARDi,t+α9DUALi,t+α10MSHAREi,t+α11OCFi,t+YEAR+IND+εi,t (3)

Empirical test and analysis

Descriptive statistics

It can be seen from Table 2 that the average value of the gap is 1.552 and the standard deviation is 0.614. The difference between the maximum value of 3.313 and the minimum value of 0.221 is nearly 14 times, which indicates that the gap among enterprises is large. The average capita remuneration of management (GWAGE) is 13.030, while the average per capita salary of ordinary employees (YWAGE) is 11.480, with a difference of 1.55, and the standard deviation of the two is 0.653 and 0.496 respectively. This also shows that the per capita salary of the ordinary employees is not as volatile as that of the management, and the per capita salary of the ordinary employees is generally less than that of the management. In addition, the amount of donation income of different enterprises is not the same. The minimum value of public welfare donation is almost 0, the maximum value is 4.622, the average value is 0.214, and the standard deviation is 0.608, which indicates that the public welfare donation of enterprises fluctuates greatly.

10.1371/journal.pone.0309387.t002 Table 2 Descriptive statistics.

Variable	Observations	Mean Value	Standard Deviation	Minimum	Median	Maximum	
GAP	16677	1.552	0.614	0.221	1.516	3.313	
GWAGE	16677	13.030	0.653	11.540	13.020	14.870	
YWAGE	16677	11.480	0.496	10.290	11.470	12.770	
Donation	16677	0.214	0.608	0.000	0.036	4.622	
SIZE	16677	22.240	1.261	20.020	22.060	26.140	
LEV	16677	0.408	0.200	0.051	0.400	0.858	
SOE	16677	0.329	0.470	0.000	0.000	1.000	
AGE	16677	9.191	7.232	0.000	8.000	26.000	
GROWTH	16677	0.299	0.750	-0.601	0.122	5.148	
TOP	16677	34.710	14.990	8.810	32.630	75.100	
INBOARD	16677	0.382	0.071	0.250	0.364	0.600	
DUAL	16677	0.289	0.453	0.000	0.000	1.000	
MSHARE	16677	0.151	0.208	0.000	0.013	0.706	
OCF	16677	19.280	1.564	15.260	19.220	23.500	

Correlation coefficient analysis of main variables

Correlation analysis. As shown in Table 3, the public welfare donation of enterprises (Donation) is significantly positively correlated with the per capita remuneration of management (GWAGE) at the level of 1%, indicating that the higher the donation expenditure of enterprises, the more the per capita remuneration of management may be, which preliminarily verifies the hypothesis of this study. Secondly, the public welfare donation of enterprises (Donation) is also significantly positively correlated with the per capita salary of ordinary employees (YWAGE) at the level of 1%, which indicates that the higher the donation expenditure of enterprises, the more the per capita salary of ordinary employees may be, but the correlation between the donation expenditure of enterprises and the per capita salary of management is lower, which preliminarily verifies the hypothesis of this study. Finally, there is a significant positive correlation between enterprise public welfare donation expenditure (Donation) and enterprise internal income gap(GAP)at the level of 1%, which indicates that the higher the amount of enterprise public welfare donation expenditure, the larger the enterprise internal income gap, which preliminarily verifies the hypothesis of this study. At the same time, this study also tested the variance expansion factor and found that the mean value of the variance expansion factor was 3.10, which was far less than 10, which showed that there was no serious multicollinearity in the regression.

10.1371/journal.pone.0309387.t003 Table 3 Correlation analysis.

	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)	(13)	(14)	
Donation	1														
GAP	0.174***	1													
GWAGE	0.277***	0.689***	1												
YWAGE	0.154***	-0.316***	0.464***	1											
SIZE	0.428***	0.199***	0.446***	0.341***	1										
LEV	0.120***	0.043***	0.121***	0.103***	0.546***	1									
SOE	0.078***	-0.095***	0.035***	0.160***	0.374***	0.325***	1								
AGE	0.128***	0.008	0.170***	0.215***	0.463***	0.405***	0.471***	1							
GROWTH	-0.004	-0.055***	0.015*	0.089***	0.033***	0.091***	0.026***	0.055***	1						
TOP	0.084***	-0.027***	-0.002	0.030***	0.162***	0.032***	0.183***	-0.089***	0.003	1					
INBOARD	-0.006	0.008	0.003	-0.006	-0.062***	-0.067***	-0.144***	-0.098***	-0.009	0.021***	1				
DUAL	-0.049***	0.024***	-0.012	-0.046***	-0.191***	-0.161***	-0.294***	-0.257***	-0.020***	-0.025***	0.095***	1			
MSHARE	-0.112***	-0.038***	-0.124***	-0.116***	-0.394***	-0.350***	-0.485***	-0.541***	-0.018**	-0.071***	0.140***	0.258***	1		
OCF	0.393***	0.231***	0.446***	0.303***	0.795***	0.354***	0.283***	0.352***	-0.021***	0.192***	-0.044***	-0.148***	-0.309***	1	
Note: The table shows the Pearson correlation coefficients for the main variables. * * *** And * indicate significant at 1%, 5% and 10% levels, respectively. See Table 1 for the definitions of all variables.

Principal regression test and analysis. First, the impact of corporate public welfare donation expenditure on the per capita remuneration of management. The regression results of model (1) are listed in Item (1) of Table 4. The regression coefficient between the enterprise’s public welfare donation expenditure (Donation)and the per capita remuneration of management(GWAGE) is 0.065, which is significantly positive at the level of 1%, which indicates that the larger the enterprise’s public welfare donation expenditure, the higher the management’s per capita salary.

10.1371/journal.pone.0309387.t004 Table 4 Gap between public welfare donations and internal income of enterprises.

Variables	(1)	(2)	(3)	
GWAGE	YWAGE	GAP	
Donation	0.065***	0.008	0.072***	
(7.57)	(1.40)	(6.36)	
SIZE	0.170***	0.068***	0.200***	
(25.06)	(13.54)	(21.83)	
LEV	-0.409***	-0.255***	-0.485***	
(-15.25)	(-12.66)	(-13.23)	
SOE	-0.053***	0.138***	-0.107***	
(-4.45)	(15.83)	(-6.77)	
AGE	-0.004***	0.002***	-0.008***	
(-5.36)	(3.80)	(-7.20)	
GROWTH	-0.011*	0.021***	-0.024**	
(-1.73)	(4.13)	(-2.55)	
TOP	-0.002***	0.001**	-0.003***	
(-7.39)	(2.45)	(-8.15)	
INBOARD	0.079	0.053	0.100	
(1.37)	(1.26)	(1.30)	
DUAL	0.027***	0.001	0.037***	
(2.91)	(0.19)	(3.00)	
MSHARE	-0.153***	-0.019	-0.194***	
(-6.47)	(-1.11)	(-6.20)	
OCF	0.088***	0.017***	0.108***	
(19.32)	(5.13)	(17.59)	
Constant	7.385***	8.860***	6.140***	
(65.56)	(104.57)	(40.40)	
YEAR	YES	YES	YES	
IND	YES	YES	YES	
Observations	16,677	16,677	16,677	
R-squared	0.361	0.417	0.281	
Note: This table contains the regression results of public welfare donations and the per capita salary of management, the per capita salary of ordinary employees, and the income gap within the enterprise. * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Second, the impact of corporate public welfare donation expenditure on the per capita salary of ordinary employees. Item (2) of Table 4 shows the regression results of model (2). The regression coefficient between the public welfare donation expenditure of the enterprise (Donation)and the per capita salary of ordinary employees (YWAGE) is 0.008, which is not significant, indicating that the excess rent brought by the public welfare donation expenditure does not significantly improve the per capita salary of ordinary employees.

Third, the impact of corporate public welfare donation expenditure on the internal income gap of enterprises. Item (3) of Table 4 shows the regression results of model (3). The regression coefficient between the enterprise’s public welfare donation expenditure (Donation) and the enterprise’s internal income gap (GAP) is 0.072, which is significantly positive at the level of 1%, indicating that the larger the public welfare donation expenditure, the larger the enterprise’s internal income gap. To sum up, the hypothesis of this study is verified.

Robustness test

Replace interpreted variable. First of all, this study attempts to re-measure the internal income gap of enterprises by taking the logarithm of the ratio of the per capita remuneration of management to the per capita remuneration of ordinary employees and defines this value as GAP1. Secondly, this study attempts to re-measure the internal income gap of enterprises according to the ratio of the per capita remuneration of management and the per capita remuneration of ordinary employees and defines this value as GAP2. Finally, this study attempts to re-measure the income gap within enterprises according to the Gini coefficient of the per capita remuneration of enterprise management and the per capita remuneration of ordinary employees and defines this value as GINI。 The calculation formula for the Gini coefficient between management and ordinary employees is: Ggy=12n2μ∑i=1N∑j=1N|aωgy,i−aωgy,j|Among them, represents the Gini coefficient of inter-group compensation, n represents the number of employees in each group, represents the number of groups, represents the overall average salary of employees, and represents the per capita salary of the i-th and j-th groups, respectively.The specific regression results are shown in Table 5. Columns (1), (2), and (3) are the regression results of the explained variables GAP1, GAP2, and GINI respectively. The regression coefficients are 0.865, 0.062, and 0.093, which are significantly and positively related to the internal income gap of enterprises at the level of 1%, indicating that the larger the public welfare donation expenditure, the larger the internal income gap of enterprises. The research conclusion of this study is stable.

10.1371/journal.pone.0309387.t005 Table 5 Replacement of explained variables and explained variables.

	(1)	(2)	(3)	(4)	
Variables	GAP1	GAP2	GINI	GAP	
Donation	0.865***	0.062***	0.093***		
(7.98)	(5.65)	(3.44)		
Donation1				0.029***	
			(11.20)	
SIZE	0.780***	0.101***	-0.769***	0.190***	
(14.12)	(13.60)	(-24.10)	(20.91)	
LEV	-1.012***	-0.163***	-2.331***	-0.478***	
(-5.29)	(-5.64)	(-16.54)	(-13.06)	
SOE	-1.314***	-0.196***	-0.551***	-0.100***	
(-13.65)	(-15.09)	(-10.71)	(-6.36)	
AGE	-0.033***	-0.007***	-0.028***	-0.008***	
(-5.06)	(-7.46)	(-7.55)	(-7.07)	
GROWTH	-0.177***	-0.032***	0.146***	-0.024***	
(-3.94)	(-4.44)	(4.19)	(-2.58)	
TOP	-0.020***	-0.003***	-0.015***	-0.003***	
(-8.17)	(-8.38)	(-10.65)	(-8.12)	
INBOARD	0.065	0.019	-1.122***	0.108	
(0.15)	(0.31)	(-4.10)	(1.40)	
DUAL	0.157**	0.024**	0.129***	0.039***	
(2.27)	(2.47)	(2.67)	(3.15)	
MSHARE	-0.926***	-0.139***	0.569***	-0.206***	
(-5.40)	(-5.57)	(4.08)	(-6.60)	
OCF	0.476***	0.071***	-0.013	0.106***	
(14.34)	(14.68)	(-0.61)	(17.17)	
Constant	-15.621***	-1.449***	22.423***	6.043***	
(-15.54)	(-11.41)	(43.91)	(41.62)	
YEAR	YES	YES	YES	YES	
IND	YES	YES	YES	YES	
Observations	16,677	16,677	16,677	16,676	
R-squared	0.189	0.169	0.297	0.285	
Note: Items (1) to (3) in this table are the regression results of public welfare donations and remeasured internal income gap (GAP1, GAP2, GINI); Item (4) is the regression result of the remeasured Donation1 and GAP. * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Replace explanatory variable. Remeasure the explanatory variable enterprise public welfare donations, that is, add 1 to the absolute number of public welfare donations to take the logarithm, and put the new indicator Donation1 back into the regression for testing. The regression results are shown in column (4) of Table 5. The regression coefficient between the public welfare donation expenditure of enterprises (Donation1) and the internal income gap of enterprises (GAP) is 0.029, which is significantly positive at the level of 1%, indicating that the larger the public welfare donation expenditure, the larger the internal income gap. The conclusion of this study is stable.

Endogenous. To further account for the presence of time-invariant features over the observation period, we incorporate firm and year fixed effects to control for these influencing factors. The regression results are presented in Table 6. Even after controlling for the firm fixed effects, the coefficient of GAP is 0.019 and significant at 1% level. This suggests that our main regression findings remain robust even after accounting for the firm fixed effects.

10.1371/journal.pone.0309387.t006 Table 6 Controlling for the firm fixed effects.

Variables	(1)	
GAP	
Donation	0.019**	
	(2.02)	
SIZE	0.267***	
	(22.94)	
LEV	-0.333***	
	(-8.06)	
SOE	0.001	
	(0.04)	
AGE	0.082***	
	(2.66)	
GROWTH	-0.029***	
	(-4.52)	
TOP	0.001	
	(0.93)	
INBOARD	0.204***	
	(3.27)	
DUAL	-0.008	
	(-0.58)	
MSHARE	-0.092*	
	(-1.76)	
OCF	0.025***	
	(5.68)	
Constant	5.761***	
	(20.33)	
YEAR	YES	
FIRM	YES	
Observations	16,677	
Chi-square	361.98***	
Note: This table is the regression results after controlling for the firm fixed effects * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Secondly, since the objects tested in this study are only companies whose public welfare donation expenditure has been disclosed and can be collected, this study also conducted the Heckman test to alleviate the problem of self-selection of samples. In the first step of Heckman’s two-step regression, the exogenous variable POLICY is added, and the POLICY index with a year less than 2017 is assigned 0, otherwise, it is 1. The reason is that China’s enterprise income tax law stipulates that the public welfare donation expenditure incurred by enterprises from 2017 is allowed to be deducted except for the part within 12% of the total annual profit; The excess part is allowed to be carried forward for three years for the deduction. The implementation of this policy will directly affect the donation number of enterprises but has no direct impact on the income gap within enterprises.

The regression results are shown in Table 7. In the first stage, probit regression is used. It can be seen that the policy regression coefficient is significantly positive at the level of 1%, and the regression coefficient is 0.091. When the IMR value estimated in the first stage is brought into the second regression, it is found that the regression coefficient between Donation and GAP is still significantly positive at the level of 1%, and the regression coefficient is 0.053, which indicates that the conclusion of this study is still stable after alleviating some endogenous problems.

10.1371/journal.pone.0309387.t007 Table 7 Heckman test.

Variables	(1)	(2)	
Firststep	Secondstep	
Donation		0.053***	
	(4.29)	
IMR		1.660***	
		(8.51)	
POLICY	0.091***		
	(4.65)		
SIZE	0.149***	0.332***	
	(10.38)	(19.07)	
LEV	0.011	-0.502***	
	(0.19)	(-13.37)	
SOE	-0.283***	-0.321***	
	(-11.23)	(-10.80)	
AGE	-0.008***	-0.014***	
	(-4.60)	(-10.48)	
GROWTH	-0.039***	-0.060***	
	(-4.39)	(-6.45)	
TOP	-0.004***	-0.007***	
	(-6.39)	(-11.96)	
INBOARD	-0.107	0.011	
	(-0.80)	(0.14)	
DUAL	0.005	0.042***	
	(0.24)	(3.32)	
MSHARE	0.002***	-0.000	
	(3.47)	(-0.42)	
OCF	0.062***	0.147***	
	(6.44)	(19.00)	
Constant	-3.401***	1.974***	
	(-15.35)	(3.97)	
YEAR	YES	YES	
IND	YES	YES	
Observations	22,059	16,307	
Pseudo R2/R-squared	0.042	0.283	
Note: This table is the regression result of the Heckman two-step method. * * *** and * indicate significant at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Heterogeneity test

China’s state-owned and non-state-owned enterprises differ greatly in salary system and bargaining power of employees, which may lead to differences in the impact of public welfare donations on the internal income gap of different types of enterprises. First of all, the salary system of state-owned enterprises is highly administrative, and the increase of management salary will be strictly restricted; However, the salary system of non-state-owned enterprises is highly market-oriented, and there will be less resistance to increasing the salary of management. Secondly, compared with ordinary employees of non-state-owned enterprises, many employees of state-owned enterprises are in the establishment, facing very low dismissal risk, and they are large in scale and have a relatively large voice. Therefore, the excess rent brought by public welfare donations may have a greater impact on the internal income gap of non-state-owned enterprises. According to column (1) of Table 8, the regression coefficient of the cross term (Donation x SOE) between the core variable of public welfare donations and corporate nature is -0.175, with a t-value of -8.97, which is significant at the 1% level. The results show that compared with state-owned enterprises, non-state-owned enterprises’ public welfare donations have a greater positive impact on the internal income gap of enterprises.

10.1371/journal.pone.0309387.t008 Table 8 Heterogeneity test.

VARIABLES	(1)	(2)	(3)	(4)	
GAP	GAP	GAP	GAP	
Donation×SOE	-0.175***				
(-8.97)				
Donation×MSHARE		0.347***			
	(4.82)			
Donation×ReportAttention			-0.001**
(-2.08)		
ReportAttention			0.005***
(17.39)		
Donation×MediaAttention				-0.038***
(-4.78)	
MediaAttention				0.114***
(8.81)	
Donation	0.164***	0.055***	0.075***	0.101***	
(11.14)	(4.55)	(4.11)	(6.50)	
SIZE	0.201***	0.199***	0.138***	0.186***	
(22.00)	(21.84)	(13.10)	(19.66)	
LEV	-0.492***	-0.490***	-0.238***	-0.499***	
(-13.45)	(-13.39)	(-5.56)	(-13.42)	
SOE	-0.060***	-0.106***	-0.095***	-0.108***	
(-3.66)	(-6.67)	(-5.34)	(-6.75)	
AGE	-0.008***	-0.008***	-0.005***	-0.007***	
(-7.90)	(-7.09)	(-4.32)	(-6.49)	
GROWTH	-0.024***	-0.024**	-0.022**	-0.022**	
(-2.59)	(-2.54)	(-2.08)	(-2.31)	
TOP	-0.003***	-0.003***	-0.003***	-0.004***	
(-7.99)	(-8.01)	(-7.70)	(-8.73)	
INBOARD	0.125	0.101	0.118	0.096	
(1.64)	(1.32)	(1.37)	(1.25)	
DUAL	0.037***	0.037***	0.023*	0.037***	
(2.98)	(2.99)	(1.71)	(3.01)	
MSHARE	-0.183***	-0.233***	-0.317***	-0.207***	
(-5.86)	(-7.23)	(-8.97)	(-6.48)	
OCF	0.107***	0.107***	0.088***	0.105***	
(17.43)	(17.42)	(12.51)	(16.92)	
Constant	6.089***	6.141***	7.703***	6.457***	
(40.16)	(40.51)	(41.44)	(39.73)	
YEAR	YES	YES	YES	YES	
IND	YES	YES	YES	YES	
Observations	16,677	16,677	12,752	16,336	
R-squared	0.285	0.282	0.315	0.287	
Note: This table shows the regression results of the heterogeneity test of the nature of ownership (SOE) 、management shareholding ratio (MSHARE)、Report Attention and Media. * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

In addition, in the capital market environment, most of the management owns a certain proportion of the shares of the enterprise, which means that the management has the status of both manager and owner. This identity strengthens its voice in sharing the excess rent brought by public welfare donations, that is, in listed companies with higher management shareholding, public welfare donations have a greater positive impact on the internal income gap of enterprises. According to column (2) of Table 8, the regression coefficient of the cross term (Donation x MSHARE) between public welfare donations and management shareholding ratio is 0.347, with a t-value of 4.82, which is significant at the 1% level. The empirical results show that public welfare donations have a greater positive impact on the internal income gap in companies with high management shareholding than those with low management shareholding.

Finally, external supervision is also an important means to promote fair distribution among enterprises. As an information intermediary in the capital market, analyst reports can enhance the transparency of enterprise information and suppress the self-interest behavior of corporate executives. It is reasonable to believe that companies with higher attention from analyst reports will be more transparent and fair in rent distribution. In addition, media coverage can also reflect the unreasonable salary gap in enterprises, triggering public attention and discussion. In order to improve their social image, enterprises will pay more attention to the salary and benefits of employees and actively take measures to narrow the salary gap; It can encourage the government and regulatory agencies to take action, promote the improvement and implementation of relevant laws and regulations, and strengthen the supervision of corporate compensation policies. According to columns (3) and (4) of Table 8, the regression coefficient of the cross term (Donation x ReportAttention) between public welfare donations and research declaration attention is -0.001, with a t-value of -2.08, which is significant at the 5% level. The regression coefficient of the cross term (Donation x MediaAttention) between public welfare donations and media attention is -0.038, with a t-value of -4.78, which is significant at the 1% level. The empirical results indicate that companies facing looser external supervision have a greater positive impact on the internal income gap of public welfare donations.

The above results show that the difference in bargaining power between ordinary employees and management is an important reason for the uneven distribution of excess rent and internal income gap caused by public welfare donations, and further verifies the robustness of the conclusions of this study.

Mechanism test

To test the intermediary effect in hypothesis deduction. This study defines tax preference as the external rent source of enterprises, defines enterprise performance (ROE) as the internal rent source of enterprises, and discusses the intermediary effect of internal and external rents respectively.

Intermediary effect of enterprise tax preference

Concerning previous studies, the actual tax negative rate (TAXR) of enterprises is taken as the measurement index of tax preference [23]. In this study, the actual tax negative rate (TAXR) of enterprises is added to the model (3) to test the intermediary effect of tax preference. The regression results are shown in Table 9. The public welfare donation expenditure (Donation) in column (1) hurts the actual tax negative rate (TAXR) of enterprises at a significant level of 1%, which indicates that more donations by enterprises will reduce the actual tax burden borne by enterprises. Relying on the tax preference given by the government, enterprises will get more rent to share internally. Column (2) shows that after adding the actual tax negative rate (TAXR) of enterprises to the model (3), the regression coefficient between the donation expenditure of enterprises and the internal income gap of enterprises is still significantly positive at the significant level of 1%, which indicates that the intermediary effect of the tax burden is established, and the result has passed Sobel test, and the amount of intermediary effect is 3.00%. That is, the increase of public welfare donation expenditure of enterprises reduces the tax negative rate, and the decrease of tax negative rate increases the internal income gap of enterprises, so the increase of public welfare donation expenditure of enterprises expands the internal income gap.

10.1371/journal.pone.0309387.t009 Table 9 Impact of public welfare donations on tax negative rate.

Variables	(1)	(2)	
TAXR	GAP	
TAXR		-0.005***	
	(-7.36)	
Donation	-0.441***	0.067***	
(-3.20)	(5.88)	
SIZE	0.171	0.189***	
(1.17)	(19.81)	
LEV	10.208***	-0.336***	
(16.00)	(-8.45)	
SOE	0.044	-0.090***	
(0.17)	(-5.46)	
AGE	0.176***	-0.007***	
(10.49)	(-5.94)	
GROWTH	-0.412***	-0.034***	
(-3.31)	(-3.51)	
TOP	0.007	-0.004***	
(1.24)	(-8.44)	
INBOARD	-0.939	0.057	
(-0.82)	(0.72)	
DUAL	-0.122	0.038***	
(-0.72)	(2.98)	
MSHARE	-1.127***	-0.209***	
(-2.84)	(-6.51)	
OCF	-0.485***	0.107***	
(-4.84)	(16.41)	
Constant	9.830***	6.413***	
(3.88)	(39.69)	
YEAR	YES	YES	
IND	YES	YES	
Observations	15,113	15,113	
R-squared	0.205	0.288	
Sobel statistic	Z = 2.809***(P<0.01)	
Proportion of intermediary effect	3.00%	
Note: This table verifies the intermediary role of the actual tax negative rate (TAXR) of enterprises in public welfare donations and the internal income gap of enterprises. * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Intermediary effect of enterprise performance

According to the production supply theory, taxation is a cost expenditure for enterprises. Tax incentives can reduce the operating costs of enterprises, keep the output level unchanged while reducing production inputs, and improve the production efficiency of enterprises. According to the theory of economic growth, as operating costs decrease, enterprises can expand their R&D investment, improve their innovation capabilities, and thereby promote the improvement of enterprise performance. Moreover, tax preferential policies can also guide enterprises to invest resources in areas with higher efficiency, which can also promote the improvement of enterprise performance. There are many research results by Chinese scholars on the impact of tax incentives on corporate performance. Empirical results show that tax incentives have a positive impact on corporate technological innovation performance, financial performance and investment performance. The pre tax deduction of public welfare donations, as an important tax preferential policy, can also play a role in increasing corporate performance.

Enterprise performance (ROE) is added to the model (3) to test the intermediary effect of internal rent sources. The regression results are shown in Table 10. The public welfare donation expenditure in column (1) has a positive impact on enterprise performance (ROE) at a significant level of 1%, which indicates that more donations by enterprises will improve their income, and relying on good operating performance, enterprises will have more rents to share internally. Column (2) shows that after adding enterprise performance (ROE) to model (3), the regression coefficient between donation and gap is still positive at the significant level of 1%, which indicates that the intermediary effect of enterprise performance is established, and the result has passed Sobel test, and the amount of intermediary effect is 49.50%. That is, the increase in the company’s public welfare donation expenditure improves the company’s performance. Due to the different bargaining power of senior executives and ordinary employees, the increase in performance widens the income gap within the enterprise.

10.1371/journal.pone.0309387.t010 Table 10 Impact of public welfare donation on performance.

Variables	(1)	(2)	
ROE	GAP	
ROE		1.575***	
	(21.68)	
Donation	0.014***	0.049***	
(11.76)	(4.46)	
SIZE	-0.014***	0.221***	
(-10.25)	(24.46)	
LEV	-0.098***	-0.331***	
(-14.90)	(-9.04)	
SOE	-0.004**	-0.100***	
(-2.15)	(-6.49)	
AGE	-0.001***	-0.007***	
(-4.28)	(-6.49)	
GROWTH	0.010***	-0.039***	
(9.21)	(-4.26)	
TOP	0.001***	-0.004***	
(12.13)	(-10.69)	
INBOARD	0.013	0.079	
(1.39)	(1.04)	
DUAL	0.002	0.034***	
(1.03)	(2.83)	
MSHARE	0.030***	-0.240***	
(7.88)	(-7.81)	
OCF	0.028***	0.064***	
(31.57)	(10.04)	
Constant	-0.137***	6.356***	
(-6.35)	(42.43)	
YEAR	YES	YES	
IND	YES	YES	
Observations	16,677	16,677	
R-squared	0.183	0.309	
Sobel statistic	Z = 13.197***(P<0.01)	
Proportion of intermediary effect	49.50%	
Note: This table verifies the intermediary role of enterprise performance (ROE) in public welfare donations and the internal income gap of enterprises. * * *** And * indicate significance at 1%, 5%, and 10% levels, respectively, and the t-value of the robust standard error is in brackets. See Table 1 for the definitions of all variables.

Conclusions and policy implications

This study uses the microdata of A-share listed companies from 2011 to 2020 to investigate the impact of public welfare donations on the internal income gap of enterprises and its mechanism. The results show that public welfare donations significantly improve the per capita salary of management, but have no significant impact on the per capita salary of ordinary employees, thus widening the income gap within enterprises. Consistent with the research of Kong, D. et al. [21], we controlled for industry and annual fixed effects in benchmark regression, thereby controlling for influencing factors that change over time or industry. In addition, to alleviate the impact of endogeneity issues on our observation results, Heckman test and control for individual fixed effects were used. This result also passed a series of robustness tests. However, despite conducting a series of robustness tests, we were unable to rule out the interference of all endogeneity issues [10]. The mechanism test results show that the income tax preference brought by public welfare donations and the improvement of enterprise operating efficiency have increased the excess rent shared by enterprises and employees. Because the management has stronger bargaining power, it shares more excess rent, which leads to the widening of the income gap within the enterprise. Finally, the results of heterogeneity analysis show that the internal income gap of non-state-owned enterprises is more affected by public welfare donations, but limiting executive compensation and enhancing employees’ bargaining power can alleviate the widening effect of public welfare donations on the internal income gap of enterprises.

Based on the analysis, the following suggestions are made: first, deepen the research on the relationship between preferential policies of enterprise income tax and income distribution, clarify the impact of different types of preferential policies of enterprise income tax on the income gap within enterprises, and provide evidence support for the government to formulate further tax reduction and fee reduction policies. Second, while using the pre–Tax Deduction Policy of income tax to encourage enterprises to make public welfare donations, we should pay attention to the introduction of supporting measures, develop a reasonable salary incentive system for senior executives, strictly control the disorderly rise of senior executives’ salaries, establish a more equitable internal salary distribution system, and achieve the simultaneous reduction of external and internal disparities. Third, the stronger the bargaining power of ordinary employees, the more helpful it is to reduce the impact of public welfare donations on the internal income gap of enterprises, which is particularly obvious in state-owned enterprises. Therefore, in the improvement of the company’s governance structure, we should further improve the voice of ordinary employees, give full play to the role of trade unions, and strengthen the supervision and management of employees over the company.

This study also has certain limitations. Firstly, due to the lack of detailed employee salary data published by listed companies, scholars have used the difference between the average salary of management and the average salary of ordinary employees to measure the income gap of enterprise employees. This study also discusses this issue. Future research can use methods such as questionnaire surveys to obtain more detailed statistics on executive and employee compensation in order to draw more accurate conclusions. Secondly, in terms of model design, considering that the rental sharing theory [18]and bargaining power theory [19], we used cannot derive high-order regression results, we did not use a similar inverted U-shaped model [23]. Future research can develop a U-shaped regression model of corporate public welfare donations on internal income inequality based on other theoretical deductions. Finally, although this study adopts the Heckman bipartite method and individual fixed effects model to alleviate the problem of endogeneity, it is undeniable that endogeneity cannot be completely eliminated. Future research can consider mandatory donation regulations implemented under certain specific institutional backgrounds, and use quasi-natural experiments to test the impact of public welfare donations on internal income disparities within enterprises.

10.1371/journal.pone.0309387.r001
Decision Letter 0
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submission Version0
17 Apr 2023

PONE-D-23-00002Public welfare donation, Rent sharing, and Income gap within enterprisesPLOS ONE

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Reviewer #1: Dear Authors,

Thank You for so interesting and relevant Article entitled "Public welfare donation, Rent sharing, and Income gap within enterprises".

1. The article is written on a relevant topic, well-structured, and logically proven.

2. The topic is highly original and relevant in the field.

3. The authors duly describe the subject area compared with other published material.

4. The authors could consider some minor improvements in the logic of the presentation of the results. I'd suggest describing some paragraphs about the Sustainability concept in a separate section Discussion. I'd recommend to move to this new separate section some considerations on limitations and future research from the last section Conclusion.

5. The conclusions are consistent with the evidence and arguments presented.

6. The references are appropriate.

7. Please disclose the abbreviations firstly appeared in the text.

Reviewer #2: 1. I have problems to understand what is meant due to incorrect English, such as CSMAR database should be “China Stock Market Accounting Research Database”. The authors should definitely employ a language editor before the paper gets published.

2. There is the logical contradiction between the first paragraph of “Theoretical analysis and research hypothesis” with the subsequent arguments, such as “when the public welfare donation promotes the improvement of the business performance of the enterprise, employees will share the rent of the enterprise”, especially the paper fails to distinguish the concepts of managers and employees in the first paragraph of “Theoretical analysis and research hypothesis” clearly.

3. Some explanatory variables in the table are labeled incorrectly(the column (4) in table 5, Table 8).

4. the paper should explain the reason of using the fixed effect model to solve what kind of endogenous problem. And the paper needs to verify the applicability of the fixed effects model through Hausman test.

5. The article requires a theoretical analysis of the reasons for the establishment of tax and performance mechanisms.

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Sergey Barykin

Reviewer #2: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

10.1371/journal.pone.0309387.r002
Author response to Decision Letter 0
Submission Version1
11 Jul 2023

Dear Editor and Reviewers,

We would like to appreciate your effort for having reviewed our submitted manuscript and giving us so many valuable suggestions and helpful comments for improving the manuscript.

In the revised manuscript, we have improved this paper thoroughly according to your suggestions and comments. And we marked the revised parts in red font.

We are highly appreciated your great support and kind help in improving the quality of this paper. Our detailed responses to all of your individual comments are described in the following parts.

1. I have problems to understand what is meant due to incorrect English, such as CSMAR database should be “China Stock Market Accounting Research Database”. The authors should definitely employ a language editor before the paper gets published.

Response 1: Thank you for your valuable suggestions. We have hired a language editor to make compliance modifications and edits to the paper.

2. There is the logical contradiction between the first paragraph of “Theoretical analysis and research hypothesis” with the subsequent arguments, such as “when the public welfare donation promotes the improvement of the business performance of the enterprise, employees will share the rent of the enterprise”, especially the paper fails to distinguish the concepts of managers and employees in the first paragraph of “Theoretical analysis and research hypothesis” clearly.

Response 2：This article provides a detailed explanation of the concepts of management and ordinary employees in the dependent variables (1) and (2). In order to provide readers with an understanding of these two concepts when reading the first paragraph, an explanation has been provided in footnote 1 of the first paragraph.

When public welfare donations promote the improvement of business performance, employees will share the rent of the company. "The term" employees "refers to all employees of the company, including management and ordinary employees.

3. Some explanatory variables in the table are labeled incorrectly(the column (4) in table 5, Table 8).

Response 3： Thank you for discovering and pointing out the issue. We have made modifications to the errors in Tables 5 and 8.

4. the paper should explain the reason of using the fixed effect model to solve what kind of endogenous problem. And the paper needs to verify the applicability of the fixed effects model through Hausman test.

Response 4：Due to the presence of certain factors in the model that may not change over time or individuals, these factors are difficult to observe and may be related to disturbance terms, ultimately leading to endogeneity issues. So in order to control for the impact of these factors, we adopted a fixed effects test to alleviate the endogeneity problem of missing variables in the model. In ad dition, this article also validated the applicability of the fixed effects model through the Hausman test, and the test results are listed in the last row of Table 6.

5. The article requires a theoretical analysis of the reasons for the establishment of tax and performance mechanisms.

Response 5： The reasons for tax and performance mechanisms have been added to the text. According to the Production Supply Theory, taxation is a costly expenditure for enterprises. Tax incentives can reduce the operating costs of enterprises, keep the output level unchanged while reducing production inputs, and improve the production efficiency of enterprises. According to the theory of economic growth, as operating costs decrease, enterprises can expand their R&D investment, improve their innovation capabilities, and thereby promote the improvement of enterprise performance. Moreover, tax preferential policies can also guide enterprises to invest resources in more efficient areas, which can also promote the improvement of enterprise performance (Tang Hongxiang et al., 2020). Chinese scholars have made a lot of research results on the impact of tax incentives on corporate performance. The empirical results show that tax incentives have a positive impact on corporate technological innovation performance (Jia Jia, 2017), financial performance (Cai Chang et al., 2017), and investment performance (Yu Guansheng et al., 2023). The pre-tax deduction of public welfare donations, as an important tax preferential policy, can also play a role in increasing corporate performance.

Attachment Submitted filename: Response to Reviewers.docx

10.1371/journal.pone.0309387.r003
Decision Letter 1
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submission Version1
20 Oct 2023

PONE-D-23-00002R1Public welfare donation, Rent sharing, and Income gap within enterprisesPLOS ONE

Dear Dr. luo,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

I think your manuscript addresses an important area which undoubtedly will be valued for our learned audience. To improve upon your manuscript further, I believe addressing the issues highlighted by the reviewers will improve it to a large extent.

Please submit your revised manuscript by Dec 03 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Yasir Ahmad

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

Reviewer #3: (No Response)

********** 2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Partly

********** 3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

********** 4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

**********5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

********** 6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Dear Authors,

Thank You for improving Your manuscript. I can see that the Authors made all requested changes to make the manuscript better.

Reviewer #2: 1.Corporate charitable donation is essentially a way of benefit sharing, and the income distribution gap between management and employees is also a manifestation of corporate social responsibility. Therefore, to some extent, this article discusses the relationship between the fulfillment of social responsibility within and outside the enterprise, or the allocation of economic resources between external and internal responsibilities of the enterprise, The article should appropriately elaborate on the impact of this issue on the research process and findings from the perspective of different forms of social responsibility.

2.The theoretical analysis section in the article involves a variety of theories: principal agent theory, effective wage theory, bargaining theory, The rent sharing theory, which are complicated and overloaded. authors should accurately and concisely use related theory to explain.

Reviewer #3: I think the paper would benefit from a strong discussion section to add to the current 'conclusions and policy' section that needs to tie everything together, with the extant literature, including why this theoretical approach was chosen, whether there are any conflicting theories that were considered, why the fixed effects approach was chosen over other statistical approaches, why these particular robustness or sensitivity tests were done and importantly explain the limitations of this statistical and theoretical approach. While some of these components are presented in the results and introduction it feels a little scattered and not cohesively tied to current literature. I especially could not find the limitations discussed anywhere.

********** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Sergey Barykin

Reviewer #2: No

Reviewer #3: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

10.1371/journal.pone.0309387.r004
Author response to Decision Letter 1
Submission Version2
3 Jan 2024

Dear Editor and Reviewers,

We would like to appreciate your effort for having reviewed our submitted manuscript and giving us so many valuable suggestions and helpful comments for improving the manuscript.

In the revised manuscript, we have improved this paper thoroughly according to your suggestions and comments. And we marked the revised parts in red font.

We are highly appreciated your great support and kind help in improving the quality of this paper. Our detailed responses to all of your individual comments are described in the following parts.

1. Corporate charitable donation is essentially a way of benefit sharing, and the income distribution gap between management and employees is also a manifestation of corporate social responsibility. Therefore, to some extent, this article discusses the relationship between the fulfillment of social responsibility within and outside the enterprise, or the allocation of economic resources between external and internal responsibilities of the enterprise, The article should appropriately elaborate on the impact of this issue on the research process and findings from the perspective of different forms of social responsibility.

Response 1: Thank you for your valuable suggestion. Corporate social responsibility includes four aspects: economic responsibility, legal responsibility, ethical responsibility, and charitable responsibility. In the introduction of the article, we elaborated on the impact of charitable donations on different forms of social responsibility. In addition, we also emphasize that the corporate social responsibility discussed in this paper specifically refers to charitable responsibility.

2. The theoretical analysis section in the article involves a variety of theories: principal agent theory, effective wage theory, bargaining theory, The rent sharing theory, which are complicated and overloaded. authors should accurately and concisely use related theory to explain.

Response 2：Thank you for your valuable suggestion. This article mainly uses rent sharing theory and bargaining theory, with the specific idea that public welfare donations increase the rent of enterprises. According to the rent sharing theory, both the management and ordinary employees of enterprises require rent sharing. Then according to the bargaining theory, the bargaining power of ordinary employees is weak, while the bargaining power of management is strong, the amount of rent shared by the two will be different, which leads to an widening income gap within the enterprise. We have adjusted the first paragraph in the theoretical analysis and research hypothesis section of the article.

3. I think the paper would benefit from a strong discussion section to add to the current 'conclusions and policy' section that needs to tie everything together, with the extant literature, including why this theoretical approach was chosen, whether there are any conflicting theories that were considered, why the fixed effects approach was chosen over other statistical approaches, why these particular robustness or sensitivity tests were done and importantly explain the limitations of this statistical and theoretical approach. While some of these components are presented in the results and introduction it feels a little scattered and not cohesively tied to current literature. I especially could not find the limitations discussed anywhere.

Response 3: Thank you for your valuable suggestion.We have made changes to the suggestions you made in our conclusions and policies.

Consistent with the research of Kong, D. et al. (2017) [35], we controlled for industry and annual fixed effects in benchmark regression, thereby controlling for influencing factors that change over time or industry. In addition, to alleviate the impact of endogeneity issues on our observation results, Heckman test[43]and control for individual fixed effects[44]were used. This result also passed a series of robustness tests. However, despite conducting a series of robustness tests, we were unable to rule out the interference of all endogeneity issues (Card et al., 2016)

In terms of research limitations, we have added content on model design. Considering that the rental sharing theory (Zhou W., et al., 2014) and bargaining power theory (Auerbach,A., 2018) we used cannot derive high-order regression results, we did not use a similar inverted U-shaped model (Liu,C. and Gao, J., 2022). Future research can develop a U-shaped regression model of corporate public welfare donations on internal income inequality based on other theoretical deductions.

It should be explained here that we have already controlled for industry annual fixed effects in the benchmark regression, in order to maintain consistency with the core reference articles. To alleviate the interference of endogeneity issues on our observed conclusions, we further utilized individual fixed effects to alleviate endogeneity issues. In this section, we have also added corresponding literature to support and compare for discussion.

Attachment Submitted filename: Response to Reviewers2.docx

10.1371/journal.pone.0309387.r005
Decision Letter 2
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submission Version2
20 May 2024

PONE-D-23-00002R2Public welfare donation, rent sharing, and income gap within enterprisesPLOS ONE

Dear Dr. luo,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

One of the reviewers has provided valuable input for improving the manuscript and I think if you could be able to address these comments in your revision, the paper will be in much shape for the larger audience. I can understand this might require a bit of time but I am sure it will be worth it.

Please submit your revised manuscript by Jul 04 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Yasir Ahmad

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: The research question of this paper is to examine the impact and mechanism of public welfare donations on the internal income gap of enterprises. The public welfare donations significantly increase the internal income gap of enterprises through the income tax benefits and the increase in corporate operating income. The research design is rigorous. The findings have certain contribution to understanding the corporate public donations and its economic consequence.

The following concerns seem to be further considered.

1.The part of “Heterogeneity test” in this paper seems too simple，the authors could add tests on industry attributes and external supervisory factors, such as media or analysts。

2.The translation marks of the paper are too obvious, especially in the part of “policy implications”. Simultaneously, there are still some wrong description. For example, “the actual tax negative rate (TAXR)”, “China Tai'an (CSMARS) database”, “Guotai An database”.

3.The authors should consider reducing the number of Chinese literature and indicating which ones are Chinese form.

4.The authors should merge and refine the last two paragraphs of the paper, or deleting them directly.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

10.1371/journal.pone.0309387.r006
Author response to Decision Letter 2
Submission Version3
9 Jun 2024

Dear Editor and Reviewers,

We would like to appreciate your effort for having reviewed our submitted manuscript and giving us so many valuable suggestions and helpful comments for improving the manuscript.

In the revised manuscript, we have improved this paper thoroughly according to your suggestions and comments. And we marked the revised parts in red font.

We are highly appreciated your great support and kind help in improving the quality of this paper. Our detailed responses to all of your individual comments are described in the following parts.

1.The part of “Heterogeneity test” in this paper seems too simple，the authors could add tests on industry attributes and external supervisory factors, such as media or analysts。

Response 1: Thank you for your valuable suggestion. In the heterogeneity test, two factors reflecting external supervision, namely Report Attention and Media Attention, are incorporated. The empirical findings indicate that a more lenient external supervision is associated with a greater positive impact of public welfare donations on the internal income gap of the enterprises.

2.The translation marks of the paper are too obvious, especially in the part of “policy implications”. Simultaneously, there are still some wrong description. For example, “the actual tax negative rate (TAXR)”, “China Tai'an (CSMARS) database”, “Guotai An database”.

Response 2: Thank you for your valuable suggestion. The issues present in the translation of the entire study have been thoroughly revised.

3.The authors should consider reducing the number of Chinese literature and indicating which ones are Chinese form.

Response 3:Thank you for your valuable advice. As the focus of this article is on income gap within Chinese enterprises, We have included all relevant Chinese literature that we have reviewed. In order to enhance the quality of this paper, 21 citations from Chinese literature have been removed, and the remaining 6 citations are numbered 11, 18, 20, 21, 22 and 24.

4.The authors should merge and refine the last two paragraphs of the paper, or deleting them directly.

Response 4: Thank you for your valuable suggestion. The final two paragraphs of the paper have been revised to address any ambiguity.

10.1371/journal.pone.0309387.r007
Decision Letter 3
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submission Version3
11 Jul 2024

PONE-D-23-00002R3Public welfare donation, rent sharing, and income gap within enterprisesPLOS ONE

Dear Dr. luo,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Kindly review the comments of reviewer 2 and appropriate modifications need to be made in the manuscript. 

Please submit your revised manuscript by Aug 25 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Yasir Ahmad

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: 1.There are missing variables " ReportAttention" and "MediaAttention" and the results of their coefficients in columns (3) and (4) of Table 8,repectively.

2.The abbreviation "CSMARS" should be "CSMAR".

3.there are Inconsistent characters in the spaces before each paragraph in this paper.

4.At the end of the paper, the "individual fixed effects model" is mentioned, but in the previous robustness test, individual fixed effect is not controlled. Simultaneouslythe use of the fixed effect model in Table 6 is confusing, the reason and process for its use should be explained.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

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Reviewer #2: No

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10.1371/journal.pone.0309387.r008
Author response to Decision Letter 3
Submission Version4
20 Jul 2024

Dear Editor and Reviewers,

We would like to appreciate your effort for having reviewed our submitted manuscript and giving us so many valuable suggestions and helpful comments for improving the manuscript.

In the revised manuscript, we have improved this paper thoroughly according to your suggestions and comments. And we marked the revised parts in red font.

We are highly appreciated your great support and kind help in improving the quality of this paper. Our detailed responses to all of your individual comments are described in the following parts.

1.There are missing variables " ReportAttention" and "MediaAttention" and the results of their coefficients in columns (3) and (4) of Table 8,repectively.

Response 1: Thank you for your valuable suggestion. We have included the outcomes of the variables "ReportAttention" and "MediaAttention" along with their coefficients in columns (3) and (4) of Table 8, demonstrating significance at the 1% level.

2.The abbreviation "CSMARS" should be "CSMAR".

Response 2: Thank you for your valuable suggestion. We have corrected the errors in the text.

3.there are Inconsistent characters in the spaces before each paragraph in this paper.

Response 3:Thank you for your valuable advice. We have changed the spaces at the beginning of each paragraph.

4.At the end of the paper, the "individual fixed effects model" is mentioned, but in the previous robustness test, individual fixed effect is not controlled. Simultaneously the use of the fixed effect model in Table 6 is confusing, the reason and process for its use should be explained.

Response 4: Thank you for your valuable suggestion. To further account for the presence of time-invariant features over the observation period, we incorporate firm and year fixed effects to control for these influencing factors. The regression results are presented in Table 6. Even after controlling for the firm fixed effects, the coefficient of GAP is 0.019 and significant at 1% level. This suggests that our main regression findings remain robust even after accounting for the firm fixed effects.

10.1371/journal.pone.0309387.r009
Decision Letter 4
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submission Version4
12 Aug 2024

Public welfare donation, rent sharing, and income gap within enterprises

PONE-D-23-00002R4

Dear Dr. Luo,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Yasir Ahmad

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: 1. The abstract needs to be further refined and its research value should be embodied.

2. The citation format of literature in the main text should be consistent（e.g. Conclusions and policy implications)

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

**********

10.1371/journal.pone.0309387.r010
Acceptance letter
Ahmad Yasir Academic Editor
© 2024 Yasir Ahmad
2024
Yasir Ahmad
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
26 Aug 2024

PONE-D-23-00002R4

PLOS ONE

Dear Dr. luo,

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team.

At this stage, our production department will prepare your paper for publication. This includes ensuring the following:

* All references, tables, and figures are properly cited

* All relevant supporting information is included in the manuscript submission,

* There are no issues that prevent the paper from being properly typeset

If revisions are needed, the production department will contact you directly to resolve them. If no revisions are needed, you will receive an email when the publication date has been set. At this time, we do not offer pre-publication proofs to authors during production of the accepted work. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few weeks to review your paper and let you know the next and final steps.

Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

If we can help with anything else, please email us at customercare@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

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on behalf of

Dr. Yasir Ahmad

Academic Editor

PLOS ONE
==== Refs
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