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Political incentives and pollution reduction in China: Evidence from firm-level emissions data

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  • Chan, Charlie
  • Fei, Long
  • Kandilov, Ivan T.
  • Zhang, Chi

Abstract

Do local political officials' promotion incentives affect pollution? While previous research has mostly focused on developed countries and employed more aggregate data, we answer this question in the context of China, an emerging economy, using confidential, granular (firm-level) data. Our analysis demonstrates that firms’ sulfur dioxide (SO2) emissions as well as emissions of other pollutants decline during periods of heightened promotion incentives for local officials across Chinese cities. The evidence suggests that the reduction in emissions was likely due to end-of-pipe treatments, instead of improvements in production technology. We find that non-state-owned enterprises, which likely have less bargaining power and face stricter regulatory constraints compared to state-owned enterprises, experience a grater reduction in their emissions during the promotion evaluation period for local officials. We document that stricter enforcement of existing environmental regulations is likely driving the decline in emissions, suggesting that perhaps during the promotion period, more pressure is exerted on local environmental protection agencies to monitor pollution.

Suggested Citation

  • Chan, Charlie & Fei, Long & Kandilov, Ivan T. & Zhang, Chi, 2025. "Political incentives and pollution reduction in China: Evidence from firm-level emissions data," Economic Modelling, Elsevier, vol. 144(C).
  • Handle: RePEc:eee:ecmode:v:144:y:2025:i:c:s0264999324003444
    DOI: 10.1016/j.econmod.2024.106987
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    as
    1. Zhang, Bing & Chen, Xiaolan & Guo, Huanxiu, 2018. "Does central supervision enhance local environmental enforcement? Quasi-experimental evidence from China," Journal of Public Economics, Elsevier, vol. 164(C), pages 70-90.
    2. Wang, Hua & Wheeler, David, 2005. "Financial incentives and endogenous enforcement in China's pollution levy system," Journal of Environmental Economics and Management, Elsevier, vol. 49(1), pages 174-196, January.
    3. Piotroski, Joseph D. & Zhang, Tianyu, 2014. "Politicians and the IPO decision: The impact of impending political promotions on IPO activity in China," Journal of Financial Economics, Elsevier, vol. 111(1), pages 111-136.
    4. Macho-Stadler, Ines & Perez-Castrillo, David, 2006. "Optimal enforcement policy and firms' emissions and compliance with environmental taxes," Journal of Environmental Economics and Management, Elsevier, vol. 51(1), pages 110-131, January.
    5. Kent Walker & Fang Wan, 2012. "The Harm of Symbolic Actions and Green-Washing: Corporate Actions and Communications on Environmental Performance and Their Financial Implications," Journal of Business Ethics, Springer, vol. 109(2), pages 227-242, August.
    6. Kedia, Simi & Rajgopal, Shiva, 2011. "Do the SEC's enforcement preferences affect corporate misconduct?," Journal of Accounting and Economics, Elsevier, vol. 51(3), pages 259-278, April.
    7. Gong, Min & He, Wei & Zhang, Nan, 2021. "Political promotion incentives and local employment," Economic Analysis and Policy, Elsevier, vol. 69(C), pages 492-502.
    8. Min Maung & Craig Wilson & Xiaobo Tang, 2016. "Political Connections and Industrial Pollution: Evidence Based on State Ownership and Environmental Levies in China," Journal of Business Ethics, Springer, vol. 138(4), pages 649-659, November.
    9. Chen, Yuyu & Jin, Ginger Zhe & Kumar, Naresh & Shi, Guang, 2013. "The promise of Beijing: Evaluating the impact of the 2008 Olympic Games on air quality," Journal of Environmental Economics and Management, Elsevier, vol. 66(3), pages 424-443.
    10. Jiankun Lu & Pi-Han Tsai, 2017. "Signal and political accountability: environmental petitions in China," Economics of Governance, Springer, vol. 18(4), pages 391-418, November.
    11. Zhou, Wubiao, 2013. "Political connections and entrepreneurial investment: Evidence from China's transition economy," Journal of Business Venturing, Elsevier, vol. 28(2), pages 299-315.
    12. Que, Wei & Zhang, Yabin & Schulze, Günther, 2019. "Is public spending behavior important for Chinese official promotion? Evidence from city-level," China Economic Review, Elsevier, vol. 54(C), pages 403-417.
    13. Feng Guo & Yonghong Liu & Mengmeng Wang & Yiyang Zhang, 2023. "When the Presidential Candidate Comes to Town: The Impact of Donald J. Trump’s Campaign Rallies on Local Firms’ Environmental and Social Performance," Journal of Business Ethics, Springer, vol. 186(3), pages 531-552, September.
    14. Chenggang Xu, 2011. "The Fundamental Institutions of China's Reforms and Development," Journal of Economic Literature, American Economic Association, vol. 49(4), pages 1076-1151, December.
    15. Adhikari, Ajay & Derashid, Chek & Zhang, Hao, 2006. "Public policy, political connections, and effective tax rates: Longitudinal evidence from Malaysia," Journal of Accounting and Public Policy, Elsevier, vol. 25(5), pages 574-595.
    16. Feng, Xunan & Johansson, Anders C. & Zhang, Tianyu, 2014. "Political participation and entrepreneurial initial public offerings in China," Journal of Comparative Economics, Elsevier, vol. 42(2), pages 269-285.
    17. Qi, Yu & Zhang, Jianshun & Chen, Jianwei, 2023. "Tax incentives, environmental regulation and firms’ emission reduction strategies: Evidence from China," Journal of Environmental Economics and Management, Elsevier, vol. 117(C).
    18. Hering, Laura & Poncet, Sandra, 2014. "Environmental policy and exports: Evidence from Chinese cities," Journal of Environmental Economics and Management, Elsevier, vol. 68(2), pages 296-318.
    19. Marin, Giovanni & Vona, Francesco, 2021. "The impact of energy prices on socioeconomic and environmental performance: Evidence from French manufacturing establishments, 1997–2015," European Economic Review, Elsevier, vol. 135(C).
    20. Jiankun LU & Pi-Han Tsai, 2017. "Signal and Political Accountability: Environmental Petitions in China," Economic Growth Centre Working Paper Series 1711, Nanyang Technological University, School of Social Sciences, Economic Growth Centre.
    21. Li, Hongbin & Zhou, Li-An, 2005. "Political turnover and economic performance: the incentive role of personnel control in China," Journal of Public Economics, Elsevier, vol. 89(9-10), pages 1743-1762, September.
    22. Simon, Daniel H. & Prince, Jeffrey T., 2016. "The effect of competition on toxic pollution releases," Journal of Environmental Economics and Management, Elsevier, vol. 79(C), pages 40-54.
    23. Qian, Xuesong & Ding, Hai & Ding, Zifang, 2023. "Governmental inspection and firm environmental protection expenditure: Evidence from China," Economic Modelling, Elsevier, vol. 123(C).
    24. Ann Terlaak & Seonghoon Kim & Taewoo Roh, 2018. "Not Good, Not Bad: The Effect of Family Control on Environmental Performance Disclosure by Business Group Firms," Journal of Business Ethics, Springer, vol. 153(4), pages 977-996, December.
    25. Guojun He & Shaoda Wang & Bing Zhang, 2020. "Watering Down Environmental Regulation in China," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 135(4), pages 2135-2185.
    26. Cole, Matthew A. & Elliott, Robert J.R. & Okubo, Toshihiro & Zhou, Ying, 2013. "The carbon dioxide emissions of firms: A spatial analysis," Journal of Environmental Economics and Management, Elsevier, vol. 65(2), pages 290-309.
    27. Chen, Shuo & Qiao, Xue & Zhu, Zhitao, 2021. "Chasing or cheating? Theory and evidence on China's GDP manipulation," Journal of Economic Behavior & Organization, Elsevier, vol. 189(C), pages 657-671.
    28. Chen, Yvonne Jie & Li, Pei & Lu, Yi, 2018. "Career concerns and multitasking local bureaucrats: Evidence of a target-based performance evaluation system in China," Journal of Development Economics, Elsevier, vol. 133(C), pages 84-101.
    29. Chen, Ye & Li, Hongbin & Zhou, Li-An, 2005. "Relative performance evaluation and the turnover of provincial leaders in China," Economics Letters, Elsevier, vol. 88(3), pages 421-425, September.
    30. Zheng, Siqi & Kahn, Matthew E. & Sun, Weizeng & Luo, Danglun, 2014. "Incentives for China's urban mayors to mitigate pollution externalities: The role of the central government and public environmentalism," Regional Science and Urban Economics, Elsevier, vol. 47(C), pages 61-71.
    31. Li, Hongbin & Meng, Lingsheng & Wang, Qian & Zhou, Li-An, 2008. "Political connections, financing and firm performance: Evidence from Chinese private firms," Journal of Development Economics, Elsevier, vol. 87(2), pages 283-299, October.
    32. Jiawei Li & Jianghong Zeng & Zhengke Ye & Xiangrong Huang, 2021. "Are Clean Technologies More Effective Than End-of-Pipe Technologies? Evidence from Chinese Manufacturing," IJERPH, MDPI, vol. 18(8), pages 1-17, April.
    33. Brandt, Loren & Van Biesebroeck, Johannes & Zhang, Yifan, 2012. "Creative accounting or creative destruction? Firm-level productivity growth in Chinese manufacturing," Journal of Development Economics, Elsevier, vol. 97(2), pages 339-351.
    34. Kong, Dongmin & Liu, Chenhao, 2024. "Centralization and regulatory enforcement: Evidence from personnel authority reform in China," Journal of Public Economics, Elsevier, vol. 229(C).
    35. Manuel Frondel & Jens Horbach & Klaus Rennings, 2007. "End‐of‐pipe or cleaner production? An empirical comparison of environmental innovation decisions across OECD countries," Business Strategy and the Environment, Wiley Blackwell, vol. 16(8), pages 571-584, December.
    36. Xiao Tang & Zhengwen Liu & Hongtao Yi, 2018. "Performance Ranking and Environmental Governance: An Empirical Study of the Mandatory Target System," Review of Policy Research, Policy Studies Organization, vol. 35(5), pages 750-772, September.
    37. Wu, Haoyi & Guo, Huanxiu & Zhang, Bing & Bu, Maoliang, 2017. "Westward movement of new polluting firms in China: Pollution reduction mandates and location choice," Journal of Comparative Economics, Elsevier, vol. 45(1), pages 119-138.
    38. Maurizio Bussolo & Simon Commander & Stavros Poupakis, 2023. "Political connections and firms: network dimensions," Oxford Economic Papers, Oxford University Press, vol. 75(1), pages 256-280.
    39. Earnhart, Dietrich & Lizal, Lubomir, 2006. "Effects of ownership and financial performance on corporate environmental performance," Journal of Comparative Economics, Elsevier, vol. 34(1), pages 111-129, March.
    40. Nie, Huihua & Jiang, Minjie & Wang, Xianghong, 2013. "The impact of political cycle: Evidence from coalmine accidents in China," Journal of Comparative Economics, Elsevier, vol. 41(4), pages 995-1011.
    41. Tang, Pengcheng & Jiang, Qisheng & Mi, Lili, 2021. "One-vote veto: The threshold effect of environmental pollution in China's economic promotion tournament," Ecological Economics, Elsevier, vol. 185(C).
    42. Dai, Mi & Maitra, Madhura & Yu, Miaojie, 2016. "Unexceptional exporter performance in China? The role of processing trade," Journal of Development Economics, Elsevier, vol. 121(C), pages 177-189.
    43. Liu, Mengdi & Shadbegian, Ronald & Zhang, Bing, 2017. "Does environmental regulation affect labor demand in China? Evidence from the textile printing and dyeing industry," Journal of Environmental Economics and Management, Elsevier, vol. 86(C), pages 277-294.
    44. Deng, Yuping & Wu, Yanrui & Xu, Helian, 2019. "Political turnover and firm pollution discharges: An empirical study," China Economic Review, Elsevier, vol. 58(C).
    45. Wu, Mingqin & Cao, Xun, 2021. "Greening the career incentive structure for local officials in China: Does less pollution increase the chances of promotion for Chinese local leaders?," Journal of Environmental Economics and Management, Elsevier, vol. 107(C).
    46. Talukdar, Debabrata & Meisner, Craig M., 2001. "Does the Private Sector Help or Hurt the Environment? Evidence from Carbon Dioxide Pollution in Developing Countries," World Development, Elsevier, vol. 29(5), pages 827-840, May.
    47. Patricia Kanashiro & Jorge Rivera, 2019. "Do Chief Sustainability Officers Make Companies Greener? The Moderating Role of Regulatory Pressures," Journal of Business Ethics, Springer, vol. 155(3), pages 687-701, March.
    48. Joseph D. Piotroski & T. J. Wong & Tianyu Zhang, 2015. "Political Incentives to Suppress Negative Information: Evidence from Chinese Listed Firms," Journal of Accounting Research, Wiley Blackwell, vol. 53(2), pages 405-459, May.
    49. Tang, Pengcheng & Jiang, Qisheng & Wang, Chao, 2024. "Beyond environmental actions: How environmental regulations stimulate strategic-political CSR engagement in China?," Energy Economics, Elsevier, vol. 129(C).
    50. Andersen, Dana C., 2017. "Do credit constraints favor dirty production? Theory and plant-level evidence," Journal of Environmental Economics and Management, Elsevier, vol. 84(C), pages 189-208.
    51. Langpap, Christian & Shimshack, Jay P., 2010. "Private citizen suits and public enforcement: Substitutes or complements?," Journal of Environmental Economics and Management, Elsevier, vol. 59(3), pages 235-249, May.
    52. Hua Wang, 2000. "Pollution charges, community pressure, and abatement cost of industrial pollution in China," Policy Research Working Paper Series 2337, The World Bank.
    53. Ling, Leng & Luo, Danglun & SHE, Guoman, 2019. "Judging a book by its Cover: The influence of physical attractiveness on the promotion of regional leaders," Journal of Economic Behavior & Organization, Elsevier, vol. 158(C), pages 1-14.
    54. Luo, Jin-hui & Gong, Manning & Lin, Yilong & Fang, Qifeng, 2016. "Political connections and stock price crash risk: Evidence from China," Economics Letters, Elsevier, vol. 147(C), pages 90-92.
    55. Kong, Dongmin & Cheng, Xu & Jiang, Xiandeng, 2021. "Effects of political promotion on local firms’ social responsibility in China," Economic Modelling, Elsevier, vol. 95(C), pages 418-429.
    56. Li, Shaomin & Xia, Jun, 2008. "The Roles and Performance of State Firms and Non-State Firms in China's Economic Transition," World Development, Elsevier, vol. 36(1), pages 39-54, January.
    57. Shaojian Chen & Hui Mao & Junqin Sun, 2022. "Low-Carbon City Construction and Corporate Carbon Reduction Performance: Evidence From a Quasi-Natural Experiment in China," Journal of Business Ethics, Springer, vol. 180(1), pages 125-143, September.
    58. Matthew E. Kahn & Pei Li & Daxuan Zhao, 2015. "Water Pollution Progress at Borders: The Role of Changes in China's Political Promotion Incentives," American Economic Journal: Economic Policy, American Economic Association, vol. 7(4), pages 223-242, November.
    59. Wang, Chunhua & Wu, JunJie & Zhang, Bing, 2018. "Environmental regulation, emissions and productivity: Evidence from Chinese COD-emitting manufacturers," Journal of Environmental Economics and Management, Elsevier, vol. 92(C), pages 54-73.
    60. Shi, Xinzheng & Xu, Zhufeng, 2018. "Environmental regulation and firm exports: Evidence from the eleventh Five-Year Plan in China," Journal of Environmental Economics and Management, Elsevier, vol. 89(C), pages 187-200.
    61. Wang, Huanhuan & Xiong, Jiaxin, 2022. "Governance on water pollution: Evidence from a new river regulatory system of China," Economic Modelling, Elsevier, vol. 113(C).
    62. Liu, Zheng & Shen, Hongtao & Welker, Michael & Zhang, Ning & Zhao, Yang, 2021. "Gone with the wind: An externality of earnings pressure," Journal of Accounting and Economics, Elsevier, vol. 72(1).
    63. Jie Chen & Danglun Luo & Guoman She & Qianwei Ying, 2017. "Incentive or Selection? A New Investigation of Local Leaders’ Political Turnover in China," Social Science Quarterly, Southwestern Social Science Association, vol. 98(1), pages 341-359, March.
    64. Yu, Jihai & Zhou, Li-An & Zhu, Guozhong, 2016. "Strategic interaction in political competition: Evidence from spatial effects across Chinese cities," Regional Science and Urban Economics, Elsevier, vol. 57(C), pages 23-37.
    65. Kong, Dongmin & Liu, Shasha & Xiang, Junyi, 2018. "Political promotion and labor investment efficiency," China Economic Review, Elsevier, vol. 50(C), pages 273-293.
    66. Zhang, Cui, 2017. "Political connections and corporate environmental responsibility: Adopting or escaping?," Energy Economics, Elsevier, vol. 68(C), pages 539-547.
    67. Jingbo Cui & Harvey Lapan & GianCarlo Moschini, 2016. "Productivity, Export, and Environmental Performance: Air Pollutants in the United States," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 98(2), pages 447-467.
    68. Qi, Yu & Yin, Aoxue & Chen, Jianwei & Yang, Chunfei & Zhan, Pengyu, 2024. "Motivating for environmental protection: Evidence from county officials in China," World Development, Elsevier, vol. 184(C).
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    More about this item

    Keywords

    Political incentives; Firm level emissions; State-owned enterprises; Micro level data; China;
    All these keywords.

    JEL classification:

    • Q52 - Agricultural and Natural Resource Economics; Environmental and Ecological Economics - - Environmental Economics - - - Pollution Control Adoption and Costs; Distributional Effects; Employment Effects
    • Q53 - Agricultural and Natural Resource Economics; Environmental and Ecological Economics - - Environmental Economics - - - Air Pollution; Water Pollution; Noise; Hazardous Waste; Solid Waste; Recycling
    • Q58 - Agricultural and Natural Resource Economics; Environmental and Ecological Economics - - Environmental Economics - - - Environmental Economics: Government Policy

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