入选股指成份股会影响企业环保投资吗?--基于沪深300指数的实证研究

Can Index Additions Influence Corporate Environmental Investment?

基于沪深300指数特有的备选股制度形成的"准自然实验",利用双重差分方法(DID)检验了股指成份股调整对企业环保投资的影响及其作用机理。研究发现,入选沪深300指数成份股后,企业环保投资显著增加,支持"治理效应假说"。作用机制分析表明,入选股指成份股可以提高分析师对企业的关注度,约束管理层的短视行为;而且在企业信息透明度低、行业竞争弱以及地区法制环境差时,入选成份股对企业环保投资的积极作用更显著。本文从资本市场制度设计角度丰富了企业环保投资影响因素的相关研究,有利于监管部门完善股指成份股调整制度,促进企业更好地履行环境责任。

Based on a quasi-natural experiment provided by the unique system of CSI300 Index,this paper conducts difference-in-differences analysis to examine the effect of CSI300 index additions on corporate environmental investment and its mediating mechanism.The results show that after being in addition to CSI300 Index,corporate environmental investment has increased significantly,supporting the"governance effect hypothesis".The mediating mechanism reveals that addition to the stock index leads to more analysts’ coverage and can constrain managerial myopia.Moreover,we find that the positive effect is stronger in lower information-opaque companies,companies in industries with lower level of product market competition and in regions with worse legal protection.The paper expands the research on the determinants of corporate environmental investment from the perspective of stock market system,which helps the regulatory authorities to improve the CSI300 adjustment system and promote corporates to fulfill environmental responsibilities.