We study the mechanics of cartel enforcement and its interaction with bidding constraints in the context of repeated procurement auctions. Under collusion, bidding constraints weaken cartels by limiting the scope for punishment. This yields a test of collusive behavior exploiting the...

This article presents the first experiment exploring the impact of debarments - the exclusion of colluding bidders - on collusion in procurement auctions. We find that debarments and their most common alternative, fines, reduce collusion and bids relative to a market with no sanction. The...