Probabilistic Verification for Obviously Strategyproof Mechanisms

TL;DR

This paper explores probabilistic verification in obviously strategyproof mechanisms, showing how to implement any social choice function with minimal verification or fines, balancing incentive compatibility and verification costs.

Contribution

It introduces a probabilistic verification model for OSP mechanisms, establishing conditions for implementing social choice functions efficiently.

Findings

Implementing any social choice function with linear verification cost.

Achieving OSP with large fines or probabilistic verification.

Balancing incentive compatibility with verification costs.

Abstract

Obviously strategyproof (OSP) mechanisms maintain the incentive compatibility of agents that are not fully rational. They have been object of a number of studies since their recent definition. A research agenda, initiated in [Ferraioli&Ventre, AAAI 2017], is to find a small (possibly, the smallest) set of conditions allowing to implement an OSP mechanism. To this aim, we define a model of probabilistic verification wherein agents are caught misbehaving with a certain probability, and show how OSP mechanisms can implement every social choice function at the cost of either imposing very large fines for lies or verifying a linear number of agents.