Research

While social media has facilitated protests and challenged democratic norms, online information campaigns could also enhance electoral accountability. High saturation campaigns—that target many voters—may ignite social effects beyond direct exposure. We experimentally evaluate the electoral impact of non-partisan Facebook ads in Mexico. Vote shares of municipal incumbent parties that engaged in zero/negligible expenditure irregularities increased by 6-7 percentage points in directly-targeted electoral precincts and 3 percentage points in untargeted precincts within treated municipalities. Both effects were greater where ads targeted 80%—rather than 20%—of the electorate. The amplifying effects of high saturation campaigns reflect interactions between citizens within more socially-connected municipalities.

Criminal organizations exert political influence through bribery, voter mobilization, and pre- and post-electoral violence. We present a model in which organized crime groups strategically choose between inducements (e.g., vote buying), punishments (e.g., violence against voters and/or candidates), or a combination of both to obtain political favors, either before or after elections. The model elucidates the mechanisms through which these choices impact voter turnout and electoral competitiveness—two critical aspects of democratic processes. We derive direct, testable empirical implications and discuss their relevance to existing and prospective research, offering insights for transparency-enhancing policies.

Social distancing policies have been widely used to curb the spread of infectious diseases such as COVID-19, but assessing their effectiveness is challenging. This study shows that widely-used methods to estimate the effects of such policies are highly sensitive to accounting, or failing to account, for the simultaneous adoption of policies and the presence of spillovers across geographies stemming from human movement. By estimating a series of nonparametric models on fine-grained mobility, epidemiological, and policy data from Mexico, this research shows that failing to consider confounders, interactions, and spillovers can change the magnitude and the sign of estimated policy effects, hampering the design of optimal public policies.

Political polarization can weaken electoral accountability by shaping how citizens process information. We examine the impact of disseminating incumbent performance information on voting behavior in a polarized setting and assess the mitigating role of a debiasing nudge. We experimentally evaluate a local CSO's Facebook ad campaign that delivered COVID-19 case and death statistics to over 2 million unique users across 500 Mexican municipalities ahead of the 2021 elections. Polling-station-level results reveal that the information alone backfired: it increased (decreased) incumbent support in areas with high (low) COVID-19 impact. These effects are driven by areas with strong prior incumbent support, prevalent communal values, and higher stress indicators among citizens. However, a debiasing nudge reversed this effect, enabling voters to reward (punish) incumbents with low (high) COVID-19 impact. Our findings underscore how biases in information processing undermine electoral accountability in polarized contexts and demonstrate the potential for nudges to restore it.

This paper studies the decision of criminal organizations to use violence or bribes to influence political outcomes. Using an asymmetric information model, I show that criminal groups resort to violence when other channels of influence, specifically bribes, become unavailable. I test the model's predictions in the context of an electoral reform in Mexico that increased politicians' cost of accepting bribes. I measure bribes using confidential administrative reports of suspicious financial transactions in retail banking and measure violence using an original dataset of attacks on politicians. Using a difference-in-differences design, I find that in areas with drug trafficking organizations, the reform led to a 4-percentage point decrease (∼650 fewer reports) in suspicious financial transactions and a 2-percentage point increase (∼44 more attacks) in attacks on politicians. Consistent with the model, further evidence indicates that (1) criminal organizations resort to violence when they fail to reach agreements with politicians, and (2) the effects of the reform are driven by municipalities where politicians have tighter campaign spending limits and possess less information about the criminal groups. These findings have implications for our understanding of local governance and call for attention to the design and implementation of transparency-enhancing electoral reforms.

Developing public policies that effectively address complex societal issues while representing diverse perspectives remains a significant challenge in governance and policy-making. This paper presents Policy Dreamer, an evolutionary dynamics-based preference aggregation method designed to create public policy that aligns with heterogeneous populations while preserving solution diversity. It does so in three stages: a) Initial Public Policy Generation (where public policies are defined as a set of goals, actions, and strategies aimed at addressing specific societal issues), b) Preference Elicitation from a constituency of humans, and c) Policy Refinement using simulated human feedback. We apply this approach to the domain of creating public policy, which require navigating complex socioeconomic trade-offs. To validate our method, we measure our system's ability to create popular yet diverse policy proposals in the following domains: Healthcare, Gun Control, and Social Media regulation. Our approach iteratively aligns policies with respect to a base constituency, while using evolutionary search to ensure that policy diversity is not compromised. When compared to an expert-crafted set of policies, it is able to generate novel policies, with up to 25% of generated policies being novel. However, it exhibits limitations in capturing the full diversity of these expert-crafted policies, particularly in controversial or emerging policy domains. Overall, our preliminary results suggest that Large Language Models (LLMs) are able to actively elicit preferences from a constituency of people, and iteratively generate statements (public policies) that align with this constituency while preventing a collapse in statement diversity.

Experimental design.

Presented at the ASSA 2025 Annual Meeting. Working paper forthcoming!

Collected initial pilot data on deliberation.io, a general-purpose deliberation platform to host online conversations. Working with partners for field experiment in Spring 2025.

Social media has been identified as a relevant factor in the global rise in political polarization. Yet, the role of political elites in this process remains unclear. Using data on mobile coverage, Facebook connections, and electoral outcomes in Mexico from 2012 to 2021, we investigate the determinants of elite-driven polarization on social media. Our findings indicate that political actors who deepened a divisive discourse during this period gained electoral benefits from increased polarization. We distinguish between mechanisms of selective exposure ("echo chambers") and diversification ("contact"), noting that electoral gains are concentrated where social media amplifies a single political voice. Conversely, exposure to an ideologically diverse network mitigates these effects. By clarifying the role of political elites and differentiating mechanisms of social media exposure, our study reconciles conflicting results in political polarization literature and offers insights into potential mitigation strategies.