Have Supermarket Mergers Raised Prices? An Event Study Analysis

Antitrust enforcement of supermarket merger activity during the late 1980s and early 1990s was less stringent than it had been before or has been since. For six announcements of supermarket acquisitions during this period, this study examines the abnormal stock returns of rival firms to determine if investors believed these acquisitions would lead to higher retail prices.These abnormal returns imply that investors expected that the average retail price change associated with these types of acquisitions ranges from a 0.12% decrease to a 0.05% increase. Thus, our results suggest that investors generally did not view these acquisitions as anticompetitive.