We use a large sample of guessed ice break-up dates for the Tanana River in Alaska to study differences between outcomes of decisions made by individuals versus groups. We estimate the distribution of guesses conditional on whether they were made by individual bettors or betting pools. We document two major distinctions between the two sets of guesses: (1) the distribution of guesses made by groups of bettors appears to conform more to the distribution of historical break-up dates than the distribution of guesses made by individual bettors, and (2) the distribution for groups has less mass in its tails and displays lower variability than the distribution for individuals. We argue that these two pieces of evidence are consistent with the hypothesis that group decisions are more moderate, either because groups have to reach a compromise when their members disagree or because individuals with extreme opinions are less likely to be part of a group.

We show that female directors have a significant impact on board inputs and firm outcomes. In a sample of US firms, we find that female directors have better attendance records than male directors, male directors have fewer attendance problems the more gender-diverse the board is, and women are more likely to join monitoring committees. These results suggest that gender-diverse boards allocate more effort to monitoring. Accordingly, we find that chief executive officer turnover is more sensitive to stock performance and directors receive more equity-based compensation in firms with more gender-diverse boards. However, the average effect of gender diversity on firm performance is negative. This negative effect is driven by companies with fewer takeover defenses. Our results suggest that mandating gender quotas for directors can reduce firm value for well-governed firms.