Ensuring access to clean water is one of the most important development and health challenges of the twenty-first century. Given the manifold impacts of business activities on water resources, corporate water actions should be of central concern to business ethics researchers. Yet so far we know too little about whether business activities that impact on water resources are noticed or how corporate water actions are valued by a firm’s stakeholders, including by financial markets. In response, we conduct an event study to investigate the shareholder wealth effect of reports of corporate water actions. We explore stock market reactions to water actions by S&P 500 firms from 2005 to 2017, showing that the market reacts positively to reports of responsible water actions and negatively to irresponsible actions. We further explain that these abnormal returns to water actions are associated with a firm’s past performance on ethical issues, arguing that the reputational effects from prior corporate social responsibility and irresponsibility influence market reactions. Our analysis provides evidence that there are diminishing marginal returns to responsible water actions for firms with records of past responsibility and an offsetting effect for those with past irresponsibility. Similarly, we demonstrate an insurance effect that limits punishment for irresponsible water actions for firms with responsible performance records and diminishing negative marginal returns for those already seen to be irresponsible. This study is the first to show that shareholders recognize market value in corporate water actions and are prepared to award or punish firms in stock markets based on their impacts on water.

确保获得清洁水是 21 世纪最重要的发展和健康挑战之一。鉴于商业活动对水资源的多方面影响，企业水资源行为应该成为商业道德研究人员的核心关注点。然而，到目前为止，我们对影响水资源的商业活动是否受到关注，或者公司的利益相关者（包括金融市场）如何评价企业水资源行为的价值知之甚少。作为回应，我们进行了一项事件研究，以调查公司水资源行动报告的股东财富效应。我们探索了股票市场对 2005 年至 2017 年标准普尔 500 指数公司的水资源行动的反应，表明市场对负责任的水资源行动的报告作出积极反应，对不负责任的行动作出消极反应。我们进一步解释说，这些对水行为的异常回报与公司过去在道德问题上的表现有关，认为先前企业社会责任和不负责任的声誉影响会影响市场反应。我们的分析提供的证据表明，对于过去有责任记录的公司而言，负责任的水资源行动的边际回报正在递减，而对于那些过去不负责任的公司，则具有抵消效应。同样，我们证明了一种保险效应，它限制了对具有负责任绩效记录的公司不负责任的水行为的惩罚，并减少了那些已经被视为不负责任的公司的负边际回报。