Collusive agreements are often observed in procurement auctions. They are probablymore easily achieved when competitors’ costs are easily estimated. If, however, the individualcosts of bidders are private information, effective ring formation is difficult to realize.We compare experimentally...

A long time ago most economists would have limited themselves to stating that agreements should be individually rational and efficient and that selecting a specific agreement from that set depends on bargaining and negotiation power whatever that may be. Nowadays hardly any economist will argue...