2 citations · 2 across the 7 of their papers we have counts for
9 papers
Deterministic Stackelberg Strategies in Robotaxi Assignment Games
Ioannis Caragiannis, Kostas Kollias, Mohammad Roghani +2
In autonomous mobility duopolies, platforms compete for riders based on vehicle proximity. A critical operational challenge---faced by an incumbent proactively defending against a…
A Unified Framework for Uniform-Price Resource Allocation Mechanisms
Ioannis Caragiannis, Dimitris Fotakis, Stratis Skoulakis
Mechanisms for allocating a divisible resource among strategic agents have been widely studied. The prominent paradigm is the proportional (Kelly) mechanism, which elicits a scalar…
The Robotaxi Placement Problem: Minimizing Expected ETA for Stochastic Demand
Ioannis Caragiannis, Kostas Kollias, Mohammad Roghani +2
Autonomous ride-hailing platforms must strategically position idle robotaxis to minimize the wait times of prospective riders. We formalize this as the robotaxi placement problem (…
The Distortion of Prior-Independent b-Matching Mechanisms
Ioannis Caragiannis, Vasilis Gkatzelis, Sebastian Homrighausen
In a setting where items need to be partitioned among agents, we evaluate the performance of mechanisms that take as input each agent's \emph{ordinal preferences}, i.e., th…
Computing Approximately Proportional Allocations of Indivisible Goods: Beyond Additive and Monotone Valuations
Martin Jupakkal Andersen, Ioannis Caragiannis, Anders Bo Ipsen +1
Although approximate notions of envy-freeness-such as envy-freeness up to one good (EF1)-have been extensively studied for indivisible goods, the seemingly simpler fairness concept…
Quantile agent utility and implications to randomized social choice
Ioannis Caragiannis, Fabian Frank, Sanjukta Roy
We initiate a novel direction in randomized social choice by proposing a new definition of agent utility for randomized outcomes. Each agent has a preference over all outcomes and…
Welfare-Optimal Serial Dictatorships have Polynomial Query Complexity
Ioannis Caragiannis, Kurt Mehlhorn, Nidhi Rathi
Serial dictatorship is a simple mechanism for coordinating agents in solving combinatorial optimization problems according to their preferences. The most representative such proble…
Estimating the Expected Social Welfare and Cost of Random Serial Dictatorship
Ioannis Caragiannis, Sebastian Homrighausen
We consider the assignment problem, where agents have to be matched to items. Each agent has a preference order over the items. In the serial dictatorship (SD) mechanism th…
New Fairness Concepts for Allocating Indivisible Items
Ioannis Caragiannis, Jugal Garg, Nidhi Rathi +2
For the fundamental problem of fairly dividing a set of indivisible items among agents, envy-freeness up to any item (EFX) and maximin fairness (MMS) are arguably the most compelli…