Effects of cross-border capital flows on stock returns of dual-listed firms in mainland China and Hong Kong: Evidence from a natural experiment

This study analyses the effects of the Shanghai–Hong Kong Stock Market Connect policy on the price disparity between A-shares and H-shares of dual-listed companies (DLC). Using a difference-in-difference estimation method, we show that the policy decreases the relative twin cumulative abnormal returns of treated DLC by 3% and narrows the price gaps between A-shares and H-shares. We determine that the rising demand for H-shares, which are newly accessible by mainland investors, drives the price of H-shares up. By contrast, the price of A-shares remains unchanged. Further analysis reveals that cross-border capital flow is the main force of the policy.