Using the Investors' Intelligence sentiment index, we employ a generalized autoregressive conditional heteroscedasticity-in-mean specification to test the impact of noise trader risk on both the formation of conditional volatility and expected return as suggested by De Long et al. [Journal of Political Economy 98 (1990) 703]. Our empirical results show that sentiment is a systematic risk that is priced. Excess returns are contemporaneously positively correlated with shifts in sentiment. Moreover, the magnitude of bullish (bearish) changes in sentiment leads to downward (upward) revisions in volatility and higher (lower) future excess returns.

We study after-hours trading (AHT), price contributions, and price discovery following quarterly earnings announcements released outside of the normal trading hours. For Standard & Poor’s (S&P) 500 index stocks from 2004–2008, AHT is heightened on announcement days. A significant portion of the price change and price discovery occurs immediately after the earnings releases. Prices in AHT show a large degree of informational efficiency, further demonstrating the importance of price discovery in AHT. We also provide evidence suggesting that firms prefer after-hours earnings announcements, as trades are mainly from informed traders, and those trades are relied upon to convey information to the general public.

We investigate the relationship between internal governance and firms' innovation. We hypothesize that internal governance stemming from the difference in expected employment horizons between a CEO and her subordinate executives improves a firm's innovation. Using the age difference between a CEO and her subordinate executives as the primary measure of internal governance, we find a strong positive relationship between internal governance and firms' innovation output, and scientific and economic values. We show that the positive relation is causal and robust based on empirical tests including exogenous variation in internal governance resulting from non-forced CEO turnovers. We further show that the relationship between internal governance and innovation is more pronounced when external governance is weaker and when subordinate executives are expected to have more influence on the board. Cross-sectional analysis shows that internal governance spurs innovation in younger firms, firms led by generalist CEOs, and when the likelihood of insider successions is higher.