Recent empirical research in finance has uncovered two families of pervasive regularities: underreaction of stock prices to news such as earnings announcements, and overreaction of stock prices to a series of good or bad news. In this paper, we present a parsimonious model of investor sentiment, or of how investors form beliefs, which is consistent with the empirical findings. The model is based on psychological evidence and produces both underreaction and overreaction for a wide range of parameter values.

This paper examines legal rules covering protection of corporate shareholders and creditors, the origin of these rules, and the quality of their enforcement in 49 countries. The results show that common‐law countries generally have the strongest, and frenchcivillaw countries the weakest, legal protections of investors, with German‐and scandinavin‐civil‐law countries located in the middle. We also find that concentration of ownership of shares in the largest public companies is negativelyrelated to investor protections, consistent with the hypothesis that small, diversified share‐holders are unlikely to be important in countries that fail to protect their rights.