This paper shows that the possibility of collusion between an agent and a supervisor imposes no restrictions on the set of implementable social choice functions (SCF) and associated payoff vectors. Any SCF and any payoff profile that are implementable if the supervisor's information was public...

A number of recent papers have proposed that a pattern of isolated winning bids may be associated with collusion. In contrast, others have suggested that bid clustering, especially of the two lowest bids, is indicative of collusion. In this paper, we present evidence from an actual procurement...

We examine the relation between consumer search and equilibrium prices when collusion is endogenously determined. We develop a theoretical model and show that average price is a U-shaped function of the measure of searchers: prices are highest when there are no searchers (local monopoly power)...

This paper studies the effect of forward contracts on the stability of collusion among firms, competing in supply functions on the spot market. A forward market can increase the range of discount factors which allow to sustain collusion. On the contrary, collusion is destabilised when a...