We estimate the deterrence effects of U.S. merger policy tools with respect to the composition of future merger notifications. Data from the Annual Reports by the U.S. DOJ and FTC allow industry based measures over the 1986-1999 period of the conditional probabilities for detection (eliciting an investigation), prosecution (eliciting an antitrust action), and severity of prosecution (eliciting prohibitions versus remedies) – deterrence variables somewhat akin to the traditional deterrence variables from the crime and punishment literature. We find both the conditional probability of detection and even more so the conditional probability of prosecution to yield deterrence effects; however, the conditional probability of eliciting a severe prosecution (prohibitions versus
remedies) does not indicate significant deterrence. These results suggest that second-request-investigations and antitrust actions (remedies and
prohibitions) generally involve deterrence; yet, prohibitions do not involve significantly more deterrence than do remedies.