5 papers
From Caricature to Collective Artifact: How Persona Construction Drives Polarization in Generative Social Simulations
Dimitris Michailidis, Petter Törnberg, Fernando P. Santos
Generative Social Simulation (GSS) leverages Large Language Models (LLMs) to create sophisticated personas that define agents with demographics, emotions, and political opinions. W…
Smart Transportation Without Neurons -- Fair Metro Network Expansion with Tabular Reinforcement Learning
Dimitris Michailidis, Sennay Ghebreab, Fernando P. Santos
We tackle the Metro Network Expansion Problem (MNEP), a subset of the Transport Network Design Problem (TNDP), which focuses on expanding metro systems to satisfy travel demand. Tr…
Inequality in Congestion Games with Learning Agents
Dimitris Michailidis, Sennay Ghebreab, Fernando P. Santos
Who benefits from expanding transport networks? While designed to improve mobility, such interventions can also create inequality. In this paper, we show that disparities arise not…
How large language models judge and influence human cooperation
Alexandre S. Pires, Laurens Samson, Sennay Ghebreab +1
Humans increasingly rely on large language models (LLMs) to support decisions in social settings. Previous work suggests that such tools shape people's moral and political judgemen…
Scalable Multi-Objective Reinforcement Learning with Fairness Guarantees using Lorenz Dominance
Dimitris Michailidis, Willem Röpke, Diederik M. Roijers +2
Multi-Objective Reinforcement Learning (MORL) aims to learn a set of policies that optimize trade-offs between multiple, often conflicting objectives. MORL is computationally more…