We present evidence that a tax bill containing antitakeover provisions proposed by the U.S. House Ways and Means Committee on October 13, 1987 and approved by the Committee on October 15 was the fundamental economic event causing the greater than 10% decline in the stock market on October 14–16, which arguably triggered the October 19 crash. The bill, which eventually passed without most of the antitakeover provisions, would have limited the deductibility of interest on debt incurred to finance corporate takeovers, leveraged buyouts and recapitalizations, and imposed other restrictions on hostile takeovers.

We use a well-developed dynamic panel generalized method of moments (GMM) estimator to alleviate endogeneity concerns in two aspects of corporate governance research: the effect of board structure on firm performance and the determinants of board structure. The estimator incorporates the dynamic nature of internal governance choices to provide valid and powerful instruments that address unobserved heterogeneity and simultaneity. We re-examine the relation between board structure and performance using the GMM estimator in a panel of 6,000 firms over a period from 1991 to 2003, and find no causal relation between board structure and current firm performance. We illustrate why other commonly used estimators that ignore the dynamic relationship between current governance and past firm performance may be biased. We discuss where it may be appropriate to consider the dynamic panel GMM estimator in corporate governance research, as well as caveats to its use.