An antitrust authority deters collusion using fines and a leniency program. Unlike in most of the earlier literature, our firms have imperfect cumulative evidence of the collusion. That is, cartel conviction is not automatic if one firm reports: reporting makes conviction only more likely, the...

An antitrust authority deters collusion using fines and a leniency program. It chooses the probability of an investigation. Firms pick the degree of collusion: The more they collude, the higher are profits, but so is the probability of detection. Firms thus trade-off higher profits against...