Jonathan M. Karpoff is Professor of Finance and Business Economics at the University of Washington Foster School of Business. This post is based on a recent paper, forthcoming in Management Science, by Professor Karpoff, Ms. Hae Mi Choi, Ms. Xiaoxia Lou, and Mr. Gerald S. Martin.
We document and examine the consequences of an important feature of enforcement activity for financial misrepresentation, that many enforcement actions for financial misrepresentation occur in industry-specific waves. In particular, one-quarter of all enforcement actions for misrepresentation initiated by the U.S. Securities and Exchange Commission or Department of Justice are clustered in 27 industry-specific waves (in 21 different industries) during our sample period of 1978-2015. As examples, the microchip industry experienced a wave of enforcement actions targeting 19 different firms during the 42-month period from August 2004 to January 2008, and the pharmaceutical industry experienced a wave of 16 targeted firms from 2001-2005.
Enforcement waves have important consequences for firms’ stock price dynamics and information spillovers that affect the share values of industry peer firms. Figure 1 illustrates the pattern of returns when firms are targeted for enforcement action during waves. The first firm in an enforcement wave experiences an abnormal stock return that averages –19.3% on the day its misconduct is revealed. There is a spillover on other firms in the same industry, which experience an average abnormal stock return of –0.30% on the same day. Subsequent targets in the enforcement wave have successively smaller drops in share values and smaller spillover effects on other firms in the same industry. By the end of the wave, newly targeted firms experience relatively small drops in share values (–13.2%) and the spillover effects on other firms are close to zero.