Chinese Journal of Applied Chemistry ›› 2025, Vol. 42 ›› Issue (11): 1585-1592.
Received:2025-10-11
Accepted:2025-08-14
Published:2025-11-01
Online:2025-12-05
About author:312633166@qq.comCLC Number:
| Varname | N | Mean | Sd | Min | Max |
|---|---|---|---|---|---|
| ROE | 39 424 | 11.27 | 15.82 | -64.39 | 59.68 |
| DPS | 22 082 | 0.163 | 0.181 | 0 | 1 |
| G_salary | 30 656 | 14.27 | 0.769 | 12.30 | 16.41 |
| Lnsize | 39 833 | 21.69 | 1.598 | 18.46 | 26.80 |
| NADR | 39 793 | 1.469 | 2.279 | 0.0317 | 15.37 |
| Growth | 38 131 | -5.027 | 292.7 | -1,977 | 905.8 |
| Cash | 39 682 | 9.383 | 28.08 | -140.5 | 123.6 |
| HT | 30 970 | 59.57 | 16.64 | 21.93 | 99.61 |
Table 1 Descriptive statistics of variables
| Varname | N | Mean | Sd | Min | Max |
|---|---|---|---|---|---|
| ROE | 39 424 | 11.27 | 15.82 | -64.39 | 59.68 |
| DPS | 22 082 | 0.163 | 0.181 | 0 | 1 |
| G_salary | 30 656 | 14.27 | 0.769 | 12.30 | 16.41 |
| Lnsize | 39 833 | 21.69 | 1.598 | 18.46 | 26.80 |
| NADR | 39 793 | 1.469 | 2.279 | 0.0317 | 15.37 |
| Growth | 38 131 | -5.027 | 292.7 | -1,977 | 905.8 |
| Cash | 39 682 | 9.383 | 28.08 | -140.5 | 123.6 |
| HT | 30 970 | 59.57 | 16.64 | 21.93 | 99.61 |
| Varname | ROE | DPS | G_salary | Lnsize | NADR | Growth | Cash | HT |
|---|---|---|---|---|---|---|---|---|
| ROE | 1 | |||||||
| DPS | 0.501*** | 1 | ||||||
| G_salary | 0.182*** | 0.233*** | 1 | |||||
| Lnsize | -0.189*** | 0.100*** | 0.496*** | 1 | ||||
| NADR | -0.130*** | -0.011 | 0.099*** | 0.408*** | 1 | |||
| Growth | 0.500*** | 0.010 | 0.067*** | -0.011** | -0.080*** | 1 | ||
| Cash | 0.189*** | 0.142*** | 0.060*** | 0.028*** | 0.016*** | 0.093*** | 1 | |
| HT | 0.258*** | 0.252*** | 0.136*** | 0.100*** | -0.062*** | 0.086*** | 0.074*** | 1 |
Table 2 A matrix of correlation coefficients between explained variables, explanatory variables and control variables
| Varname | ROE | DPS | G_salary | Lnsize | NADR | Growth | Cash | HT |
|---|---|---|---|---|---|---|---|---|
| ROE | 1 | |||||||
| DPS | 0.501*** | 1 | ||||||
| G_salary | 0.182*** | 0.233*** | 1 | |||||
| Lnsize | -0.189*** | 0.100*** | 0.496*** | 1 | ||||
| NADR | -0.130*** | -0.011 | 0.099*** | 0.408*** | 1 | |||
| Growth | 0.500*** | 0.010 | 0.067*** | -0.011** | -0.080*** | 1 | ||
| Cash | 0.189*** | 0.142*** | 0.060*** | 0.028*** | 0.016*** | 0.093*** | 1 | |
| HT | 0.258*** | 0.252*** | 0.136*** | 0.100*** | -0.062*** | 0.086*** | 0.074*** | 1 |
| Varname | 无股利 | 有股利 | 低股利 | 高股利 |
|---|---|---|---|---|
| G_salary | -0.309 | 2.464*** | 1.470*** | 2.089*** |
| (-1.110) | (32.78) | (18.21) | (15.02) | |
| Lnsize | 0.422** | -0.423*** | -0.525*** | -0.272*** |
| (2.550) | (-9.060) | (-10.32) | (-3.400) | |
| NADR | -1.241*** | 0.253*** | 0.528*** | 0.086* |
| (-18.60) | (7.90) | (13.60) | (1.770) | |
| Growth | 0.022*** | 0.013*** | 0.011*** | 0.024*** |
| (62.19) | (37.22) | (33.13) | (25.71) | |
| Cash | 0.042*** | 0.035*** | 0.016*** | 0.033*** |
| (7.270) | (18.29) | (8.020) | (9.240) | |
| HT | 0.140*** | 0.111*** | 0.067*** | 0.075*** |
| (11.56) | (35.08) | (20.04) | (11.89) | |
| _cons | -7.846** | -23.46*** | -6.177*** | -15.54*** |
| (-1.980) | (-21.13) | (-5.030) | (-7.730) | |
| N | 8 122 | 21 696 | 14 761 | 6 935 |
| r2_a | 0.378 | 0.163 | 0.118 | 0.140 |
| F | 824.5 | 704.0 | 330.6 | 189.9 |
| F test | 0 | 0 | 0 | 0 |
Table 3 Executive compensation and profitability regression results
| Varname | 无股利 | 有股利 | 低股利 | 高股利 |
|---|---|---|---|---|
| G_salary | -0.309 | 2.464*** | 1.470*** | 2.089*** |
| (-1.110) | (32.78) | (18.21) | (15.02) | |
| Lnsize | 0.422** | -0.423*** | -0.525*** | -0.272*** |
| (2.550) | (-9.060) | (-10.32) | (-3.400) | |
| NADR | -1.241*** | 0.253*** | 0.528*** | 0.086* |
| (-18.60) | (7.90) | (13.60) | (1.770) | |
| Growth | 0.022*** | 0.013*** | 0.011*** | 0.024*** |
| (62.19) | (37.22) | (33.13) | (25.71) | |
| Cash | 0.042*** | 0.035*** | 0.016*** | 0.033*** |
| (7.270) | (18.29) | (8.020) | (9.240) | |
| HT | 0.140*** | 0.111*** | 0.067*** | 0.075*** |
| (11.56) | (35.08) | (20.04) | (11.89) | |
| _cons | -7.846** | -23.46*** | -6.177*** | -15.54*** |
| (-1.980) | (-21.13) | (-5.030) | (-7.730) | |
| N | 8 122 | 21 696 | 14 761 | 6 935 |
| r2_a | 0.378 | 0.163 | 0.118 | 0.140 |
| F | 824.5 | 704.0 | 330.6 | 189.9 |
| F test | 0 | 0 | 0 | 0 |
| Varname | 低薪酬 | 高薪酬 |
|---|---|---|
| DPS | 19.41*** | 19.53*** |
| (47.16) | (59.81) | |
| Lnsize | -0.265*** | -0.496*** |
| (-4.350) | (-9.080) | |
| NADR | 0.598*** | 0.451*** |
| (10.28) | (12.80) | |
| Growth | 0.011*** | 0.014*** |
| (29.50) | (27.02) | |
| Cash | 0.026*** | 0.013*** |
| (9.010) | (5.810) | |
| HT | 0.073*** | 0.042*** |
| (18.10) | (10.09) | |
| _cons | 6.746*** | 15.498*** |
| (5.08) | (12.76) | |
| N | 11,213 | 10,550 |
| r2_a | 0.282 | 0.332 |
| F | 734.3 | 876.5 |
| F test | 0 | 0 |
Table 4 Regression results of cash dividends and profitability
| Varname | 低薪酬 | 高薪酬 |
|---|---|---|
| DPS | 19.41*** | 19.53*** |
| (47.16) | (59.81) | |
| Lnsize | -0.265*** | -0.496*** |
| (-4.350) | (-9.080) | |
| NADR | 0.598*** | 0.451*** |
| (10.28) | (12.80) | |
| Growth | 0.011*** | 0.014*** |
| (29.50) | (27.02) | |
| Cash | 0.026*** | 0.013*** |
| (9.010) | (5.810) | |
| HT | 0.073*** | 0.042*** |
| (18.10) | (10.09) | |
| _cons | 6.746*** | 15.498*** |
| (5.08) | (12.76) | |
| N | 11,213 | 10,550 |
| r2_a | 0.282 | 0.332 |
| F | 734.3 | 876.5 |
| F test | 0 | 0 |
| Varname | 模型Ⅰ | 模型Ⅲ | 模型Ⅳ |
|---|---|---|---|
| G_salary | 2.464*** | 0.058*** | 1.366*** |
| (32.78) | (32.33) | (19.89) | |
| DPS | 18.988*** | ||
| (74.62) | |||
| Lnsize | -0.423*** | 0.005*** | -0.518*** |
| (-9.061) | (4.503) | (-12.43) | |
| NADR | 0.253*** | -0.010*** | 0.435*** |
| (7.903) | (-12.54) | (15.16) | |
| Growth | 0.013*** | 0.000*** | 0.012*** |
| (37.22) | (3.304) | (40.04) | |
| Cash | 0.035*** | 0.001*** | 0.018*** |
| (18.29) | (19.94) | (10.30) | |
| HT | 0.111*** | 0.003*** | 0.057*** |
| (35.08) | (37.93) | (19.47) | |
| _cons | -23.462*** | -0.956*** | -5.317*** |
| (-21.13) | (-36.15) | (-5.21) | |
| N | 21 696 | 21 696 | 21 696 |
| r2_a | 0.163 | 0.139 | 0.334 |
| F | 704.0 | 586.5 | 1 554 |
| F test | 0 | 0 | 0 |
Table 5 The intermediate effect test results of cash dividends
| Varname | 模型Ⅰ | 模型Ⅲ | 模型Ⅳ |
|---|---|---|---|
| G_salary | 2.464*** | 0.058*** | 1.366*** |
| (32.78) | (32.33) | (19.89) | |
| DPS | 18.988*** | ||
| (74.62) | |||
| Lnsize | -0.423*** | 0.005*** | -0.518*** |
| (-9.061) | (4.503) | (-12.43) | |
| NADR | 0.253*** | -0.010*** | 0.435*** |
| (7.903) | (-12.54) | (15.16) | |
| Growth | 0.013*** | 0.000*** | 0.012*** |
| (37.22) | (3.304) | (40.04) | |
| Cash | 0.035*** | 0.001*** | 0.018*** |
| (18.29) | (19.94) | (10.30) | |
| HT | 0.111*** | 0.003*** | 0.057*** |
| (35.08) | (37.93) | (19.47) | |
| _cons | -23.462*** | -0.956*** | -5.317*** |
| (-21.13) | (-36.15) | (-5.21) | |
| N | 21 696 | 21 696 | 21 696 |
| r2_a | 0.163 | 0.139 | 0.334 |
| F | 704.0 | 586.5 | 1 554 |
| F test | 0 | 0 | 0 |
| Varname | 无股利 | 有股利 | 低股利 | 高股利 |
|---|---|---|---|---|
| D_salary | 0.084 | 2.054*** | 1.307*** | 1.628*** |
| (0.332) | (30.89) | (18.26) | (13.45) | |
| Lnsize | 0.381** | -0.199*** | -0.422*** | -0.037 |
| (2.35) | (-4.48) | (-8.67) | (-0.49) | |
| NADR | -1.185*** | 0.233*** | 0.524*** | 0.060 |
| (-17.89) | (7.25) | (13.51) | (1.233) | |
| Growth | 0.022*** | 0.013*** | 0.011*** | 0.023*** |
| (62.32) | (36.78) | (32.92) | (25.50) | |
| Cash | 0.043*** | 0.034*** | 0.016*** | 0.032*** |
| (7.571) | (18.00) | (7.832) | (9.000) | |
| HT | 0.138*** | 0.113*** | 0.067*** | 0.078*** |
| (11.50) | (35.71) | (20.14) | (12.27) | |
| _cons | -12.449*** | -22.382*** | -5.988*** | -14.006*** |
| (-.312) | (-20.08) | (-4.890) | (-6.923) | |
| N | 8 150 | 21 729 | 14 777 | 6 952 |
| r2_a | 0.377 | 0.158 | 0.118 | 0.134 |
| F | 822.7 | 680.0 | 330.2 | 180.7 |
| F test | 0 | 0 | 0 | 0 |
Table 6 Director compensation and profitability regression results
| Varname | 无股利 | 有股利 | 低股利 | 高股利 |
|---|---|---|---|---|
| D_salary | 0.084 | 2.054*** | 1.307*** | 1.628*** |
| (0.332) | (30.89) | (18.26) | (13.45) | |
| Lnsize | 0.381** | -0.199*** | -0.422*** | -0.037 |
| (2.35) | (-4.48) | (-8.67) | (-0.49) | |
| NADR | -1.185*** | 0.233*** | 0.524*** | 0.060 |
| (-17.89) | (7.25) | (13.51) | (1.233) | |
| Growth | 0.022*** | 0.013*** | 0.011*** | 0.023*** |
| (62.32) | (36.78) | (32.92) | (25.50) | |
| Cash | 0.043*** | 0.034*** | 0.016*** | 0.032*** |
| (7.571) | (18.00) | (7.832) | (9.000) | |
| HT | 0.138*** | 0.113*** | 0.067*** | 0.078*** |
| (11.50) | (35.71) | (20.14) | (12.27) | |
| _cons | -12.449*** | -22.382*** | -5.988*** | -14.006*** |
| (-.312) | (-20.08) | (-4.890) | (-6.923) | |
| N | 8 150 | 21 729 | 14 777 | 6 952 |
| r2_a | 0.377 | 0.158 | 0.118 | 0.134 |
| F | 822.7 | 680.0 | 330.2 | 180.7 |
| F test | 0 | 0 | 0 | 0 |
| Varname | 低薪酬 | 高薪酬 |
|---|---|---|
| DPS | 1.749*** | 1.978*** |
| (92.34) | (112.9) | |
| Lnsize | 0.012*** | 0.010*** |
| (4.342) | (3.321) | |
| NADR | 0.001 | 0.025*** |
| (0.292) | (13.02) | |
| Growth | 0.000*** | 0.000*** |
| (20.81) | (14.98) | |
| Cash | 0.000 | 0.000 |
| (0.101) | (1.223) | |
| HT | 0.003*** | 0.001*** |
| (16.99) | (3.760) | |
| Constant | -0.275*** | -0.088 |
| (-4.502) | (-1.352) | |
| N | 11 212 | 10 550 |
| r2_a | 0.502 | 0.586 |
| F | 1 883 | 2 486 |
| F test | 0 | 0 |
Table 7 Cash dividends and profitability (EPS) regression results
| Varname | 低薪酬 | 高薪酬 |
|---|---|---|
| DPS | 1.749*** | 1.978*** |
| (92.34) | (112.9) | |
| Lnsize | 0.012*** | 0.010*** |
| (4.342) | (3.321) | |
| NADR | 0.001 | 0.025*** |
| (0.292) | (13.02) | |
| Growth | 0.000*** | 0.000*** |
| (20.81) | (14.98) | |
| Cash | 0.000 | 0.000 |
| (0.101) | (1.223) | |
| HT | 0.003*** | 0.001*** |
| (16.99) | (3.760) | |
| Constant | -0.275*** | -0.088 |
| (-4.502) | (-1.352) | |
| N | 11 212 | 10 550 |
| r2_a | 0.502 | 0.586 |
| F | 1 883 | 2 486 |
| F test | 0 | 0 |
| [1] | 牛翠萍, 耿修林. 企业家精神,管理层权力与企业可持续发展绩效的实证[J]. 统计与决策, 2020(19): 164-168. |
| NIU C P, GENG X L. Entrepreneurial spirit, managerial power and corporate sustainable development performance: an empirical study[J]. Stat Decis, 2020(19): 164-168. | |
| [2] | 闫邹先. 防范合谋与上市公司高管薪酬合理化测度研究[J]. 财贸研究, 2008, 19(6): 90-94. |
| YAN Z X. Collusion prevention and rationalization measurement of executive compensation in listed companies[J]. Financ Trade Res, 2008, 19(6): 90-94. | |
| [3] | 潘爱玲, 吴倩, 李京伟. 高管薪酬外部公平性,机构投资者与并购溢价[J]. 南开管理评论, 2021(1): 39-49,59-60. |
| PAN A L, WU Q, LI J W. External fairness of executive compensation, institutional investors, and merger premiums[J]. Nankai Bus Rev, 2021(1): 39-49, 59-60. | |
| [4] | 刘星, 汪洋. 高管权力,高管薪酬与现金股利分配[J]. 经济与管理研究, 2014(11): 115-123. |
| LIU X, WANG Y. Executive power, executive compensation, and cash dividend distribution[J]. Res Econ Manag, 2014(11): 115-123. | |
| [5] | JENSEN M C, MURPHY K J. Performance pay and top-management incentives[J]. J Polit Econ, 1990, 98(2): 225-264. |
| [6] | 周嘉南, 黄登仕. 上市公司高级管理层报酬业绩敏感度与风险之间关系的实证检验[J]. 会计研究, 2006(4): 44-50, 94. |
| ZHOU J N, HUANG D S. Empirical analysis on the relationship between executive compensation-performance sensitivity and risk in listed companies[J]. Account Res, 2006(4): 44-50, 94. | |
| [7] | 张刘柳. 中央企业上市公司高管薪酬与盈利能力相关性研究[D]. 西安: 西安工程大学, 2015. |
| ZHANG L L. Research on the correlation between executive compensation and profitability in central enterprise listed companies[D]. Xi′an: Xi′an Polytechnic University, 2015. | |
| [8] | 傅传锐, 戴青云, 温皓晴. 高管货币薪酬与低碳投资——来自我国A股高碳排放行业上市公司的经验证据[J]. 福建商学院学报, 2023(6): 30-38. |
| FU C R, DAI Q Y, WEN H Q. Executive monetary compensation and low-carbon investment: empirical evidence from A-share high-carbon emission listed companies in China[J]. J Fujian Bus Coll, 2023(6): 30-38. | |
| [9] | 吴育辉, 吴世农. 高管薪酬:激励还是自利?——来自中国上市公司的证据[J]. 会计研究, 2010, 11: 40-48,96-97. |
| WU Y H, WU S N. Executive compensation: incentive or self-interest? evidence from Chinese listed companies[J]. Account Res, 2010(11): 40-48, 96-97. | |
| [10] | 刘桑晨, 郝莉莉. 高管薪酬与公司盈利能力关系研究——基于服装业上市公司[J]. 商情, 2020(9): 81-82. |
| LIU S C, HAO L L. Research on the relationship between executive compensation and corporate profitability: evidence from listed apparel companies[J]. Commer Outlook, 2020(9): 81-82. | |
| [11] | 龚光明, 龙立. 股利支付水平、股利稳定性与企业价值——来自我国A股市场的经验证据[J]. 财会通讯, 2009(27): 3-5, 22, 161. |
| GONG G M, LONG L. Dividend payment level, dividend stability, and corporate value: empirical evidence from China′s A-share market[J]. Account Commun, 2009(27): 3-5, 22, 161. | |
| [12] | 罗进辉. 机构投资者持股、现金股利政策与公司价值——来自2005-2010年中国上市公司的经验证据[J].投资研究, 2013, 32(1): 56-74. |
| LUO J H. Institutional ownership, cash dividend policy, and firm value: evidence from Chinese listed companies (2005-2010)[J]. Invest Res, 2013, 32(1): 56-74. | |
| [13] | 陈振华, 马永开. 现金股利政策与上市公司代理成本实证研究[J]. 华东经济管理, 2005, 19(11): 64-68. |
| CHEN Z H, MA Y K. Cash dividend policy and agency costs of listed companies: an empirical study[J]. East China Econ Manage, 2005, 19(11): 64-68. | |
| [14] | 罗宏, 黄文华. 国企分红,在职消费与公司业绩[J]. 管理世界, 2008(9): 139-148. |
| LUO H, HUANG W H. State-owned enterprise dividends, perk consumption, and corporate performance[J]. Manage World, 2008(9): 139-148. | |
| [15] | 徐寿福, 徐龙炳. 现金股利政策,代理成本与公司绩效[J]. 管理科学, 2015, 28(1): 96-110. |
| XU S F, XU L B. Cash dividend policy, agency costs, and corporate performance[J]. J Manag Sci, 2015, 28(1): 96-110. |
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