6 papers
Selling an Item Among a Strategic Bidder and a Profiled Agent
Ioannis Caragiannis, Georgios Kalantzis
We consider the fundamental scenario where a single item is to be sold to one of two agents. Both agents draw their valuation for the item from the same probability distribution. H…
Proportional Fairness in Non-Centroid Clustering
Ioannis Caragiannis, Evi Micha, Nisarg Shah
We revisit the recently developed framework of proportionally fair clustering, where the goal is to provide group fairness guarantees that become stronger for groups of data points…
Can a Few Decide for Many? The Metric Distortion of Sortition
Ioannis Caragiannis, Evi Micha, Jannik Peters
Recent works have studied the design of algorithms for selecting representative sortition panels. However, the most central question remains unaddressed: Do these panels reflect th…
An impossibility result for strongly group-strategyproof multi-winner approval-based voting
Ioannis Caragiannis, Rob LeGrand, Evangelos Markakis +1
Multi-winner approval-based voting has received considerable attention recently. A voting rule in this setting takes as input ballots in which each agent approves a subset of the a…
Low-Distortion Clustering with Ordinal and Limited Cardinal Information
Jakob Burkhardt, Ioannis Caragiannis, Karl Fehrs +3
Motivated by recent work in computational social choice, we extend the metric distortion framework to clustering problems. Given a set of agents located in an underlying metric…
Randomized learning-augmented auctions with revenue guarantees
Ioannis Caragiannis, Georgios Kalantzis
We consider the fundamental problem of designing a truthful single-item auction with the challenging objective of extracting a large fraction of the highest agent valuation as reve…