Willard F. Mueller and Frederick E. Geithman (1991) test the competing free-rider (efficiency) and market-power explanations of certain vertical restraints once used by the Sealy mattress company and declared illegal after 1980. They estimate that eliminating the restraints increased sales and argue that this supports only the market-power explanation. However, Mueller and Geithman overlook the rise in Sealy's profits that occurred after 1980, a fact which renders their test inconclusive.

We use event-time methodology to study legal insider trading associated with mergers circa 1900. For mergers with “prospective” disclosures similar to today's, we find substantial value gains at announcement, implying participation by “out-side” shareholders despite the absence of insider constraints. Furthermore, preannouncement stock-price runups, relative to total value gain, are no more than those observed for modern mergers. Insider regulation apparently has produced little benefit for outsiders, with the inside information-pricing function and related gains shifting to external “information specialists.” Other results suggest market penalties for nondisclosure; i.e., insider trading is less successful in a restricted information environment.

Jean-Claude Bosch, E. Woodrow Eckard, Jr., The Profitability of Price Fixing: Evidence From Stock Market Reaction to Federal Indictments, The Review of Economics and Statistics, Vol. 73, No. 2 (May, 1991), pp. 309-317

The authors estimate the probability that a price fixing conspiracy will be indicated by federal authorities to be at most between 0.13 and 0.17 in a given year. The authors' estimate is based on conspiracy durations calculated from data reported for a large sample of Department of Justice cases, and a statistical birth and death process model describing the onset and duration of conspiracies.