Stock index constituent adjustments and corporate social responsibility: evidence from a quasi-natural experiment of CSI 300 index adjustments

The stock price index is a thermometer reflecting changes in the stock market, and can convey key information on capital market dynamics and trends to investors. This paper empirically investigates the impact of index adjustments on corporate social responsibility performance by employing the quasi-natural experiment of CSI 300 index adjustments. We find that index additions significantly promote corporate social responsibility performance. Mechanism analysis supports the shareholder value maximisation motivation that drives the fulfilment of corporate social responsibility. In addition, more analyst following and investor attention plays a significant mediating role in the promotion impact of stock index additions on corporate social responsibility. Further analyses show that the positive impact of the stock index additions on corporate social responsibility performance is more pronounced in industries with more competitive product market. However, index deletions do not significantly reduce corporate social responsibility performance, implying that index additions and index deletions have asymmetric effects.