A firm’s board of directors is responsible for monitoring and evaluating senior management. Central to the
board’s effectiveness is the question of board structure (size and independence). The literature on the impact of
board size on firm value is mixed. The literature suggests that increased board size has two competing effects:
greater monitoring versus more rigid decision-making. Yermack (1996) finds that smaller boards are more
efficient as they provide greater decision making. In contrast, Harris and Raviv’s (2006) model of boards
trades off additional monitoring services with free-riding and predicts that larger boards will provide optimal
monitoring when managers’ opportunities to consume private benefits are high. Boone, Field, Karpoff, and
Raheja (2007) find evidence consistent with Harris and Raviv’s predictions.