Collusive Practices in Repeated English Auctions: Experimental Evidence on Bidding Rings

This paper documents the impacts of several practices that may facilitate low sale prices when multiple units are sold at repeated English auctions. Laboratory English auction markets are created. The number of symmetric buyers attending the auction is either six or two, with total demand in these two environments held constant. The six-buyer market is intended to represent a relatively competitive environment, while auctions with two buyers represent rivalry with substantial monopsony power held by each agent. These two market environments are used to study how selected treatments, or facilitating influences, affect the behavior of buying agents.