I study the causes and effects of modern social movements, using original and rich data sources, with a specific focus on the role of social media. I am particularly interested in empowering movements affecting minorities and marginalized groups.

Job Market paper

• Can chants in the street change politics’ tune? Evidence from the 15M movement in Spain – Latest version

  Abstract: What are the long term effects of protests? This paper studies how the level of attendance at simultaneous marches organized by the 15M (the Spanish Occupy movement) impacted electoral behavior and political attitudes in the following decade. Using regional variation in weather shocks as an instrumental variable for the level of attendance at simultaneous marches, I find that cities with higher attendance are more concerned about corruption and vote more for left wing and anti-corruption parties and less for far-right parties. Using novel data from Twitter, I document, for the first time, a higher uptake of social media platforms after an offline protest and a persistent difference in online activity in cities with higher attendance. Using survey data, I also show a higher and longer-lasting electoral effect for people that have a social media account. Overall, this paper shows that street protests can have long-lasting effects on political concerns and electoral choices, explained, in part, by the creation of a persistent online social network.

Working papers

• Late Adoption and Collective Action: Social Media Expansion and the Diffusion of Black Lives Matter – Current draft. Joint with Avetian, Vladimir; Sardoschau, Sulin; and Saxena, Kritika.

  Abstract: This paper explores the impact of social media expansion in its later stages on collective action, focusing on Black Lives Matter (BLM) protests in 2020. Using data from over 100 million tweets and leveraging plausibly exogenous variation in super spreading events, we show that pandemic exposure increased social media adoption in predominantly white, rural, and Republican-leaning counties. “Late adopters” played a crucial role in spreading online and offline BLM protests to new areas, mobilizing more effectively than existing users. Our evidence suggests a shift in preferences among late adopters, beyond merely reducing coordination costs.

• Triggers and barriers to political empowerment: Evidence from Black Lives Matter – Current draft

  Abstract: This paper sudies the triggers, barriers and factors favoring political empowerment through protest in the context of the Black Lives Matter movement (BLM) in the period 2014–2018 in the US. Using high-profile police-caused deaths of Blacks as a quasi-exogenous national protest trigger, and two-way fixed effects for counties and days, I study the differential effects of various local characteristics on offline protest behavior and online BLM activity. After confirming that police-related Black deaths are an important predictor of protests, and more so in places with a higher share of Black population, results show the following: 1) Past protest in the county itself and in surrounding areas increase the likelihood of observing a BLM event after a new trigger, even more so if past protest are larger, are closer geographically to the county or are closer in time to the date of a new trigger; 2) past local police-related deaths are linked to an increase in BLM protest and online discussion after a non-local police-related death that gained national media attention 3) economic resource deprivation reduces both protest behavior and online engagement in BLM debates, suggesting the existence of a “protest poverty trap”; 4) higher inequality increases the number of protests but not the likelihood of observing a first protest in a county that has never protested before, suggesting that unfavorable local context can be reinterpreted after exposure to a more negative narrative about it (for example during a protest); 5) more social links are related to an increase of the number of protests but not to the likelihood of observing a first protest, suggesting that having experienced a protest can reveal information about others’ political preferences in the region, allowing individuals to be less reluctant when taking advantage of their social network to push forward their protest agenda; 6) a higher ability to participate in formal ways in the political debate (such as participating in elections) reduces the protest behavior, suggesting that formal and informal means of political participation substitute each other.

• Anti-immigration protest and hate crime: evidence from Germany, joint with Sardoschau, Sulin.

  Abstract: Can gatherings of people with anti-migration views cause an increase in hate crimes against migrants? We study the effects of protests organized every Monday by PEGIDA (Patriotic Europeans Against the Islamicisation of the Occident) on subsequent hate crime activity against migrants. Preliminary results suggest that having a protest on a Monday increases the probability of having at least a hate crime committed against migrants in the following week in the same municipality and more so if the protests occurred under pleasant weather.

• Diffusion of protest through Social Media: Evidence from Nahel protest in France, joint with Meón, Pierre Guillaume and Stephan, Paul.

  Abstract: We study how social media contribute to the geographic diffusion of riots. To do so, we study how riots spurred by the death of Nahel Merzouk in the hands of the police in France spread over mainland France in the early summer of 2023. From 27 June to 4 July, violent protests involving several thousand participants took place in 553 municipalities, including municipalities that had never witnessed that type of event. We use the geolocation of posts and comments on TikTok and Instagram talking about the death of Nahel Merzouk to create a measure of network exposure to previous riots in municipalities without any previous riots. Exploiting the panel dimension of social media posts and riots, we find that higher exposure to riots on a day increases the probability of hosting a riot on the day that follows. The effect is higher if the municipality has a higher share of young population and a higher share of immigrants.

Work in progress

• What do we lose when women don’t code?, joint with Rossi, Davide; Zacchiroli, Stefano and Zimmermann, Théo.

• Social media and gender norms: Evidence from 8M marches in Mexico, joint with Larreguy, Horacio and Zago, Eduardo.

• Formal and informal ways of political participation: the Voting Rights Act and the Black Lives Matter movement, joint with Bernini, Andrea.

• Diffusion of hate speech and out-group discrimination: evidence from Instagram, joint with Kerkhof, Anna and Reiner, Helmut.

Published, peer-reviewed papers

• Impact of switching bug trackers: a case study on a medium-sized open source project. Joint work with Zimmermann, Théo. 2019 IEEE International Conference on Software Maintenance and Evolution (ICSME).

  Abstract: For most software projects, the bug tracker is an essential tool. In open source development, this tool plays an even more central role as it is generally open to all users, who are encouraged to test the software and report bugs. Previous studies have highlighted the act of reporting a bug as a first step leading a user to become an active contributor. The impact of the bug reporting environment on the bug tracking activity is difficult to assess because of the lack of comparison points. In this paper, we take advantage of the switch, from Bugzilla to GitHub, of the bug tracker of Coq, a medium-sized open source project, to evaluate and interpret the impact that such a change can have. We first report on the switch itself, including the migration of preexisting issues. Then we analyze data from before and after the switch using a regression discontinuity design, an econometric methodology imported from quantitative policy analysis. We complete this quantitative analysis with qualitative data from interviews with developers. We show that the switch induces an increase in bug reporting, particularly from principal developers themselves, and more generally an increased engagement with the bug tracking platform, with more comments by developers and also more external commentators.

• La crisis en femenino plural (The crisis in plural femenine). Joint work with Martinez-Castells, Ángels. Revista de Economía Crítica 9. 2010.