How many cartels are there? The answer is important in assessing the need for 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. We take the model to data from a period of...

We study cartel contracts using data on 18 contract clauses of 109 legal Finnish manufacturing cartels whose legal status is reminiscent of e.g. the U.S Sugar Institute. One third of the clauses relate to raising profits; the others deal with instability through incentive compatibility, cartel...