How many cartels are there? The answer is important in assessing the efficiency of competition policy. We present a Hidden Markov Model that answers the question, taking into account that often we do not know whether a cartel exists in an industry or not. Our model identifies key policy...

We study cartel contracts using data on 18 contract clauses of 109 legal Finnish manufacturing cartels. One third of the clauses relate to raising profits; the others deal with instability through incentive compatibility,cartel organization, or external threats. Cartels use three main approaches...

A common approach to merger simulations used in antitrust cases is to calibrate demand from market shares and a few additional parameters. When the products involved in the merger case are differentiated along several dimensions, the resulting diversion ratios may be very different from those...

This paper deals with the enforcement of merger policy, and aims to study how merger emedies affect the deterrence accomplished by controlling mergers. We determine the optimal frequency of investigations launched by the agency, and identify situations where the introduction of remedies can lead...

This study develops and uses a successive oligopoly model, with an unobservable non-linear tariff between upstream and downstream firms, to analyze the possible anti-competitive effects of an upstream merger. We nd that an upstream merger may lead to higher average prices paid by downstream...

The economics of crime and punishment postulates that higher punishment leads to lower crime levels, or less severe crime. It is however hard to get empirical support for this intuitive relationship. This paper o¤ers a model that contributes to explain why this is the case. We show that if...

Farrell and Shapiro proposed a simple test of the possible upward pricing pressure (UPP) following a merger. They showed that the test may give false negatives, that is, indicate that a merger may not give an UPP, while a more comprehensive test would indicate the opposite. We show that their...