Aris Filos-Ratsikas

Rectifying market externalities via AI policymaking

Abstract Traditional competitive markets do not account for negative externalities; indirect costs that some participants impose on others, such as the cost of over-appropriating a common-pool resource (which diminishes future stock, and thus harvest, for everyone). Quantifying a...

On the Computation of Equilibria in Discrete First-Price Auctions

Abstract. We study the computational complexity of computing Bayes–Nash equilibria in first-price auctions with discrete value distributions and discrete bidding space under general subjective beliefs. It is known that such auctions do not always have pure equilibria. In this pap...

PPAD-Membership for Problems With Exact Rational Solutions: A General Approach via Convex Optimization

Abstract. We introduce a general technique for proving membership of search problems with exact rational solutions in PPAD, one of the most well-known classes containing total search problems with polynomial-time verifiable solutions. In particular, we construct a “pseudogate,” c...