Gonzalo Ballestero

Gonzalo Ballestero

I am a Ph.D. candidate in Economics at Penn State University.

I am an applied microeconomist working at the intersection of market design and industrial organization.

Here you can find my curriculum vitae.

You can contact me at gballestero@psu.edu.

Visit our AI and the Economy Initiative at Penn State.

Working Papers

Strategic Algorithmic Monoculture: Experimental Evidence from Coordination Games (with Hadi Hosseini, Samarth Khanna, Ran I. Shorrer)

AI agents increasingly operate in multi-agent environments where outcomes depend on coordination. We distinguish primary algorithmic monoculture (baseline action similarity) from strategic algorithmic monoculture, whereby agents adjust similarity in response to incentives. We implement a simple experimental design that cleanly separates these forces, and deploy it on human and large language model (LLM) subjects. LLMs exhibit high levels of baseline similarity (primary monoculture) and, like humans, they regulate it in response to coordination incentives (strategic monoculture). While LLMs coordinate extremely well on similar actions, they lag behind humans in sustaining heterogeneity when divergence is rewarded.

Publications

Algorithmic Collusion under Sequential Pricing and Stochastic Costs
Forthcoming at the International Journal of Industrial Organization, April 2026

The use of pricing algorithms raises concerns about algorithmic collusion. This paper considers a sequential pricing model where marginal cost fluctuates over time. I find that Q-learning algorithms autonomously collude even under cost uncertainty. Collusion is sustained by strategies that involve reward-punishment schemes. It suggests that cost uncertainty is not an obstacle to autonomous algorithmic collusion.

Work in Progress

Centralized Admission Mechanisms and International Migration

Information Frictions and Biased Beliefs in Centralized Admissions

Publications (prior to the PhD)

Traducción Contextualizada de un Marco de Responsabilidad: Dinámica Nanotecnológica en Argentina (with Pablo Herrera and Javier García Fronti)
Nanotecnología y Sociedad en Argentina. Vol. I, pp. 183-200, 2021

Análisis de la Cualificación de las Restricciones en el Teorema de Kuhn–Tucker (with Pablo Herrera)
Revista de Investigación en Modelos Matemáticos Aplicados a la Gestión y la Economía, 34 (2019): 26–39

Policy Briefs

Fraude en el Examen de Ingreso al Sistema Nacional de Residencias Médicas, July 2025

El Sistema Nacional de Residencias Médicas: Hacia un Acceso Más Equitativo (with Mariana Gudiño and Nahir Lera), June 2025