Event studies can also give guidance on whether government challenges to mergers have been perceived by the market as preventing antitrust harm. If the government challenges a merger that would lead to higher consumer prices because of the elimination of competition, that challenge should lead to a decline in the value of the merged firm’s rivals, who would benefit from the general increased price level. In a 2004 research paper, Tulane’s C. Edward Fee and University of Pittsburgh’s Shawn Thomas investigate that possibility and do not find evidence to support it. There may be anticompetitive mergers going on, but government agencies don’t seem to be able to identify them in their challenges.
More research is needed to reconcile these event studies with postmerger pricing and accounting information. If the merged firm is more efficient than the premerger firms, presumably measured profits should rise. That link has been hard to establish. Perhaps this is because of the difficulty of using accounting information, though I find that explanation unsatisfying. Some detailed studies of individual mergers have been more successful. There is evidence that CEOs who fail to deliver the anticipated value of a merger get replaced. But there is more work to be done to reconcile these results with the stock-price behavior documented by event studies. Moreover, there have been relatively few merger retrospectives on pricing in the industrial-organization literature, but that is changing. Linking up these postmerger studies on profits and individual pricing with event studies at the time of the merger would fill a gap in the literature. All of these advances are made possible by Gene’s contribution from decades before.
The effect of regulation is another question of great interest to industrial-organization economists. University of Rochester’s G. William Schwert describes clearly how event studies can assist in the study of regulation. Since that article was published in 1981, a large number of studies have done what Schwert suggests. Event studies have proven enormously valuable here, though again there are many complicated issues related to identifying the right event windows and figuring out how the regulations have affected the riskiness of the firms. The obvious question is how proposed and implemented regulations have affected the value of firms in the industry. If regulation protects consumers by limiting the exercise of market power on prices, regulations should reduce the profits of firms and lower their value. On the other hand, if producer groups use regulations to their advantage, for example by reducing competition, greater regulation might increase stock market value.
There have now been numerous event-study investigations of the effects of regulation and deregulation. The Federal Reserve’s Robin A. Prager used an event study to show that the creation of the Interstate Commerce Commission (ICC) in 1887 can be viewed as an attempt by the railroads to create a regulatory authority that would limit the amount of railroad competition, to the detriment of consumers. The creation of that regulatory authority is associated with an increase in the value of railroads. Early court decisions that limited the power of the ICC to protect railroads from competition typically reduced the value of railroads. The ICC subsequently was captured by the customers of railroads and wound up harming the value of railroads.
There also have been numerous studies of the effect of deregulation of various industries using event studies. For example, MIT’s Nancy L. Rose uses an event study to show that deregulation of trucking in the 1980s led to large declines in the value of certain trucking firms, suggesting that the earlier regulations were used to prevent competition in trucking. University of Oregon’s Larry Y. Dann and University of Florida’s Christopher M. James find that the permission to issue variable-rate money-market certificates in the 1970s lowered the value of savings and loans. The 1980 deregulations, which allowed banks to offer a greater variety of services, helped large banks and hurt small ones. Central Connecticut State University’s Kathy Czyrnik and University of Connecticut’s Linda Schmid Klein use event studies to show that repeal of the Glass-Steagall Act increased the value of commercial and investment banks.