This paper reports results from an experiment studying how fines, leniency programs and reward schemes for whistleblowers affect cartel formation and prices. Antitrust without leniency reduces cartel formation, but increases cartel prices: subjects use costly fines as (altruistic) punishments....

We review current methods for calculating fines against cartels in the US and EU, and simulate their deterrence effects under different assumptions on the legal and economic environment. It is likely that European fines have not had significant deterrence effects before leniency programs were...