We consider a second price auction between bidders with independently and identically distributed valuations, where a losing bidder suffers a negative direct externality. Considering ex-ante commitments to form bidding rings we study the question of core stability of the grand coalition, namely:...

We consider a second price auction between bidders with independently and identically distributed valuations, where a losing bidder suffers a negative direct externality. Considering ex-ante commitments to form bidding rings we study the question of core stability of the grand coalition, namely:...

We study a first-price auction preceded by a negotiation stage with complete information, during which bidders may form a bidding ring. We prove that in the absence of externalities, the grand cartel forms in equilibrium, allowing ring members to gain the auctioned object for a minimal price....

We propose a semi-cooperative game theoretic approach to check whether a given coalition is stable in a Bayesian game with independent private values. The ex ante expected utilities of coalitions, at an incentive compatible (noncooperative) coalitional equilibrium, describe a (cooperative)...

We propose a semi-cooperative game theoretic approach to check whether a given coalition is stable in a Bayesian game with independent private values. The ex ante expected utilities of coalitions, at an incentive compatible (noncooperative) coalitional equilibrium, describe a (cooperative)...

We study a first price auction preceded by a negotiation stage, during which bidders may form a bidding ring. We prove that in the absence of external effects the all-inclusive ring forms in equilibrium, allowing ring members to gain the auctioned object for a minimal price. However, identity...