1 Board Diversity and Firm Performance Volatility

Diverse directors may have diverse preferences over firms’ policies or even objectives. As shown by Arrow (1951), diverse individual preferences may fail to univocally aggregate in collective preferences and may consequently lead to arbitrary and volatile decisions. Using the board of directors as a laboratory, we test whether diversity leads to higher performance volatility. We show that firms with more diverse boards have greater stock return and fundamental volatility suggesting that board diversity indeed makes decision-making more erratic. Also, firms with diverse boards have less persistent strategies and analysts make larger forecast errors in predicting their performance supporting the conjecture that board members’ diverse preferences lead to arbitrary and hard to predict decisions. Consistent with the presence of conflicts in the boardroom, we find that executive and director turnovers are higher in firms with diverse boards. These firms also have more board meetings. We find no evidence that our results may be driven by firm risk-taking or complexity.