We show that an executive is optimistic about her company׳s prospects if and only if she retains some of the shares received whenever she exercises company stock options. Empirically, an indicator of optimism based on this idea matches the expected relations between optimism and corporate decision-making better than commonly used indicators based on the timing of option exercise. This makes sense, as our model of an executive׳s optimal option exercise and portfolio choice demonstrates that the timing of option exercise depends just as much on stock and other executive characteristics as it does on optimism.

Theoretical models of groups suggest that sub-group usage can affect communication among members and group decision-making. To examine the trade-offs from forming sub-groups, we assemble a detailed dataset on corporate boards (groups) and committees (sub-groups). Boards have increasingly used committees formally staffed entirely by outside directors. Our data show that twenty-five percent of all director meetings occurred in such committees in 1996; this increased to 45% by 2010. Our evidence suggests that granting formal authority to such committees can impair communication and decision-making. Sub-groups are relatively understudied, but our results suggest that they play an important role in group functioning and corporate governance.