We study a notion of locally robust implementation that captures the idea that the planner may know agentsʼ beliefs well, but not perfectly. Locally robust implementation is a weaker concept than ex-post implementation, but we show that no regular allocation function is locally robust...

Combining the result of Palfrey (1983) about the role of bundling and the revenue equivalence theorem, this note shows that there is a conflict between revenue maximization and efficiency in multi-object auctions even with symmetric bidders.

We study a model that involves identity-dependent, asymmetric negative external effects. Willingness to pay, which can be computed only in equilibrium, will reflect, besides private valuations, also preemptive incentives stemming from the desire to minimize the negative externalities. We find...

We analyse the interplay between license auctions and market structure in a model with several incumbents and several potential entrants. The focus is on the competitiveness induced by the number of auctioned licences. Moreover, we study how the auction format affects the incentives for explicit...

We study multi-object auctions where agents have private and additive valuations for heterogeneous objects. We focus on the revenue properties of a class of dominant strategy mechanisms where a weight is assigned to each partition of objects. The weights influence the probability with which...

We study efficient, Bayes-Nash incentive compatible mechanisms in a general social choice setting that allows for informationally interdependent valuations and for allocative externalities. We show that such mechanisms exist only if a congruence condition relating private and social rates of...

We study the effects of allocative and informational externalities in (multi-object) auctions and related mechanisms. Such externalities naturally arise in models that embed auctions in larger economic contexts. In particular, they appear when there is downstream interaction among bidders after...