Collusive dominant-strategy truthfulness

Collusive dominant-strategy truthfulness

We show that collusion and wrong beliefs may cause a dramatic efficiency loss in the Vickrey mechanism for auctioning a single good in limited supply. We thus put forward a new mechanism guaranteeing efficiency in a very adversarial collusion model, where the players can partition themselves into arbitrarily many coalitions, exchange money with each other, and perfectly coordinate their actions...

Asymptotic Dominant Strategy Truthfulness in Ascending Price Auctions

At the very beginning of the semester, we saw an incredibly powerful tool in mechanism design: the VCG mechanism. You remember: the VCG mechanism lets us find the welfare-optimal solution for any social choice problem, and pair it with payments that makes truthful reporting of one’s preferences a dominant strategy for every player. Pretty impressive! Yet, one-shot direct revelation mechanisms a...

Almost-dominant Strategy Implementation

Though some economic environments provide allocation rules that are implementable in dominant strategies (strategy-proof), a significant number of environments yield impossibility results. On the other hand, while there are quite general possibility results regarding implementation in Nash or Bayesian equilibrium, these equilibrium concepts make strong assumptions about the knowledge that playe...

The Geometry of Truthfulness

We study the geometrical shape of the partitions of the input space created by the allocation rule of a truthful mechanism for multi-unit auctions with multidimensional types and additive quasilinear utilities. We introduce a new method for describing the allocation graph and the geometry of truthful mechanisms for an arbitrary number of items(/tasks). Applying this method we characterize all p...

Notes on Dominant-Strategy Mechanisms