In this study, we examine how the concentration of authority within the board of directors affects the variability of firm performance. Using directors' committee assignments as a proxy for decision-making power, we develop two unique measures of board concentration of authority. We find that firms with greater concentration of power within their boards have higher variability in firm performance. In additional tests, we demonstrate that our results are not driven by endogeneity bias. Finally, we also show concentrated boards adopt more extreme corporate strategies, providing several different mechanisms through which board concentration of power affects firm performance volatility.

We study the stock market reactions to the Tax Cuts and Jobs Act (TCJA), the most significant structural U.S. tax reform in over 30 years. In line with the stated intent of TCJA proponents, we find that the Act benefited highly taxed firms. However, the Act hindered firms with international operations as well as firms with high interest expense and tax losses. Counter to claims that the TCJA would quickly spur economic growth, we find that financially constrained and high growth opportunity firms did not benefit. Rather, market participants anticipate that most of the TCJA's benefits will be passed on to shareholders via higher corporate payouts. We confirm these market expectations by documenting that firms did increase payouts via repurchases after the TCJA, but did not increase their corporate investments.