Academic Research

CSMaP faculty, postdoctoral fellows, and students publish rigorous, peer-reviewed research in top academic journals and post working papers sharing ongoing work.

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  • Working Paper

    Understanding Latino Political Engagement and Activity on Social Media

    Working Paper, November 2024

    View Article View abstract

    Social media is used by millions of Americans to access news and politics. Yet there are no studies, to date, examining whether these behaviors systematically vary for those whose political incorporation process is distinct from those in the majority. We fill this void by examining how Latino online political activity compares to that of white Americans and the role of language in Latinos’ online political engagement. We hypothesize that Latino online political activity is comparable to white Americans. Moreover, given media reports suggesting that greater quantities of political misinformation are circulating on Spanish versus English-language social media, we expect that reliance on Spanish-language social media for news predicts beliefs in inaccurate political narratives. Our survey findings, which we believe to be the largest original survey of the online political activity of Latinos and whites, reveal support for these expectations. Latino social media political activity, as measured by sharing/viewing news, talking about politics, and following politicians, is comparable to whites, both in self-reported and digital trace data. Latinos also turned to social media for news about COVID-19 more often than did whites. Finally, Latinos relying on Spanish-language social media usage for news predicts beliefs in election fraud in the 2020 U.S. Presidential election.

  • Journal Article

    The Effects of Facebook and Instagram on the 2020 Election: A Deactivation Experiment

    • Hunt Alcott, 
    • Matthew Gentzkow, 
    • Winter Mason, 
    • Arjun Wilkins, 
    • Pablo Barberá
    • Taylor Brown, 
    • Juan Carlos Cisneros, 
    • Adriana Crespo-Tenorio, 
    • Drew Dimmery, 
    • Deen Freelon, 
    • Sandra González-Bailón
    • Andrew M. Guess
    • Young Mie Kim, 
    • David Lazer, 
    • Neil Malhotra, 
    • Devra Moehler, 
    • Sameer Nair-Desai, 
    • Houda Nait El Barj, 
    • Brendan Nyhan, 
    • Ana Carolina Paixao de Queiroz, 
    • Jennifer Pan, 
    • Jaime Settle, 
    • Emily Thorson, 
    • Rebekah Tromble, 
    • Carlos Velasco Rivera, 
    • Benjamin Wittenbrink, 
    • Magdalena Wojcieszak
    • Saam Zahedian, 
    • Annie Franco, 
    • Chad Kiewiet De Jong, 
    • Natalie Jomini Stroud, 
    • Joshua A. Tucker

    Proceedings of the National Academy of Sciences, 2024

    View Article View abstract

    We study the effect of Facebook and Instagram access on political beliefs, attitudes, and behavior by randomizing a subset of 19,857 Facebook users and 15,585 Instagram users to deactivate their accounts for 6 wk before the 2020 U.S. election. We report four key findings. First, both Facebook and Instagram deactivation reduced an index of political participation (driven mainly by reduced participation online). Second, Facebook deactivation had no significant effect on an index of knowledge, but secondary analyses suggest that it reduced knowledge of general news while possibly also decreasing belief in misinformation circulating online. Third, Facebook deactivation may have reduced self-reported net votes for Trump, though this effect does not meet our preregistered significance threshold. Finally, the effects of both Facebook and Instagram deactivation on affective and issue polarization, perceived legitimacy of the election, candidate favorability, and voter turnout were all precisely estimated and close to zero.

  • Journal Article

    Like-Minded Sources On Facebook Are Prevalent But Not Polarizing

    • Brendan Nyhan, 
    • Jaime Settle, 
    • Emily Thorson, 
    • Magdalena Wojcieszak
    • Pablo Barberá
    • Annie Y. Chen, 
    • Hunt Alcott, 
    • Taylor Brown, 
    • Adriana Crespo-Tenorio, 
    • Drew Dimmery, 
    • Deen Freelon, 
    • Matthew Gentzkow, 
    • Sandra González-Bailón
    • Andrew M. Guess
    • Edward Kennedy, 
    • Young Mie Kim, 
    • David Lazer, 
    • Neil Malhotra, 
    • Devra Moehler, 
    • Jennifer Pan, 
    • Daniel Robert Thomas, 
    • Rebekah Tromble, 
    • Carlos Velasco Rivera, 
    • Arjun Wilkins, 
    • Beixian Xiong, 
    • Chad Kiewiet De Jong, 
    • Annie Franco, 
    • Winter Mason, 
    • Natalie Jomini Stroud, 
    • Joshua A. Tucker

    Nature, 2023

    View Article View abstract

    Many critics raise concerns about the prevalence of ‘echo chambers’ on social media and their potential role in increasing political polarization. However, the lack of available data and the challenges of conducting large-scale field experiments have made it difficult to assess the scope of the problem1,2. Here we present data from 2020 for the entire population of active adult Facebook users in the USA showing that content from ‘like-minded’ sources constitutes the majority of what people see on the platform, although political information and news represent only a small fraction of these exposures. To evaluate a potential response to concerns about the effects of echo chambers, we conducted a multi-wave field experiment on Facebook among 23,377 users for whom we reduced exposure to content from like-minded sources during the 2020 US presidential election by about one-third. We found that the intervention increased their exposure to content from cross-cutting sources and decreased exposure to uncivil language, but had no measurable effects on eight preregistered attitudinal measures such as affective polarization, ideological extremity, candidate evaluations and belief in false claims. These precisely estimated results suggest that although exposure to content from like-minded sources on social media is common, reducing its prevalence during the 2020 US presidential election did not correspondingly reduce polarization in beliefs or attitudes.

  • Journal Article

    How Do Social Media Feed Algorithms Affect Attitudes and Behavior in an Election Campaign?

    • Andrew M. Guess
    • Neil Malhotra, 
    • Jennifer Pan, 
    • Pablo Barberá
    • Hunt Alcott, 
    • Taylor Brown, 
    • Adriana Crespo-Tenorio, 
    • Drew Dimmery, 
    • Deen Freelon, 
    • Matthew Gentzkow, 
    • Sandra González-Bailón
    • Edward Kennedy, 
    • Young Mie Kim, 
    • David Lazer, 
    • Devra Moehler, 
    • Brendan Nyhan, 
    • Jaime Settle, 
    • Calos Velasco-Rivera, 
    • Daniel Robert Thomas, 
    • Emily Thorson, 
    • Rebekah Tromble, 
    • Beixian Xiong, 
    • Chad Kiewiet De Jong, 
    • Annie Franco, 
    • Winter Mason, 
    • Natalie Jomini Stroud, 
    • Joshua A. Tucker

    Science, 2023

    View Article View abstract

    We investigated the effects of Facebook’s and Instagram’s feed algorithms during the 2020 US election. We assigned a sample of consenting users to reverse-chronologically-ordered feeds instead of the default algorithms. Moving users out of algorithmic feeds substantially decreased the time they spent on the platforms and their activity. The chronological feed also affected exposure to content: The amount of political and untrustworthy content they saw increased on both platforms, the amount of content classified as uncivil or containing slur words they saw decreased on Facebook, and the amount of content from moderate friends and sources with ideologically mixed audiences they saw increased on Facebook. Despite these substantial changes in users’ on-platform experience, the chronological feed did not significantly alter levels of issue polarization, affective polarization, political knowledge, or other key attitudes during the 3-month study period.

  • Journal Article

    Reshares on Social Media Amplify Political News But Do Not Detectably Affect Beliefs or Opinions

    • Andrew M. Guess
    • Neil Malhotra, 
    • Jennifer Pan, 
    • Pablo Barberá
    • Hunt Alcott, 
    • Taylor Brown, 
    • Adriana Crespo-Tenorio, 
    • Drew Dimmery, 
    • Deen Freelon, 
    • Matthew Gentzkow, 
    • Sandra González-Bailón
    • Edward Kennedy, 
    • Young Mie Kim, 
    • David Lazer, 
    • Devra Moehler, 
    • Brendan Nyhan, 
    • Carlos Velasco Rivera, 
    • Jaime Settle, 
    • Daniel Robert Thomas, 
    • Emily Thorson, 
    • Rebekah Tromble, 
    • Arjun Wilkins, 
    • Magdalena Wojcieszak
    • Beixian Xiong, 
    • Chad Kiewiet De Jong, 
    • Annie Franco, 
    • Winter Mason, 
    • Natalie Jomini Stroud, 
    • Joshua A. Tucker

    Science, 2023

    View Article View abstract

    We studied the effects of exposure to reshared content on Facebook during the 2020 US election by assigning a random set of consenting, US-based users to feeds that did not contain any reshares over a 3-month period. We find that removing reshared content substantially decreases the amount of political news, including content from untrustworthy sources, to which users are exposed; decreases overall clicks and reactions; and reduces partisan news clicks. Further, we observe that removing reshared content produces clear decreases in news knowledge within the sample, although there is some uncertainty about how this would generalize to all users. Contrary to expectations, the treatment does not significantly affect political polarization or any measure of individual-level political attitudes.

  • Journal Article

    Asymmetric Ideological Segregation In Exposure To Political News on Facebook

    • Sandra González-Bailón
    • David Lazer, 
    • Pablo Barberá
    • Meiqing Zhang, 
    • Hunt Alcott, 
    • Taylor Brown, 
    • Adriana Crespo-Tenorio, 
    • Deen Freelon, 
    • Matthew Gentzkow, 
    • Andrew M. Guess
    • Shanto Iyengar, 
    • Young Mie Kim, 
    • Neil Malhotra, 
    • Devra Moehler, 
    • Brendan Nyhan, 
    • Jennifer Pan, 
    • Caros Velasco Rivera, 
    • Jaime Settle, 
    • Emily Thorson, 
    • Rebekah Tromble, 
    • Arjun Wilkins, 
    • Magdalena Wojcieszak
    • Chad Kiewiet De Jong, 
    • Annie Franco, 
    • Winter Mason, 
    • Joshua A. Tucker
    • Natalie Jomini Stroud

    Science, 2023

    View Article View abstract

    Does Facebook enable ideological segregation in political news consumption? We analyzed exposure to news during the US 2020 election using aggregated data for 208 million US Facebook users. We compared the inventory of all political news that users could have seen in their feeds with the information that they saw (after algorithmic curation) and the information with which they engaged. We show that (i) ideological segregation is high and increases as we shift from potential exposure to actual exposure to engagement; (ii) there is an asymmetry between conservative and liberal audiences, with a substantial corner of the news ecosystem consumed exclusively by conservatives; and (iii) most misinformation, as identified by Meta’s Third-Party Fact-Checking Program, exists within this homogeneously conservative corner, which has no equivalent on the liberal side. Sources favored by conservative audiences were more prevalent on Facebook’s news ecosystem than those favored by liberals.

  • Book

    Computational Social Science for Policy and Quality of Democracy: Public Opinion, Hate Speech, Misinformation, and Foreign Influence Campaigns

    Handbook of Computational Social Science for Policy, 2023

    View Book View abstract

    The intersection of social media and politics is yet another realm in which Computational Social Science has a paramount role to play. In this review, I examine the questions that computational social scientists are attempting to answer – as well as the tools and methods they are developing to do so – in three areas where the rise of social media has led to concerns about the quality of democracy in the digital information era: online hate; misinformation; and foreign influence campaigns. I begin, however, by considering a precursor of these topics – and also a potential hope for social media to be able to positively impact the quality of democracy – by exploring attempts to measure public opinion online using Computational Social Science methods. In all four areas, computational social scientists have made great strides in providing information to policy makers and the public regarding the evolution of these very complex phenomena but in all cases could do more to inform public policy with better access to the necessary data; this point is discussed in more detail in the conclusion of the review.

  • Journal Article

    Twitter Flagged Donald Trump’s Tweets with Election Misinformation: They Continued to Spread Both On and Off the Platform

    Harvard Kennedy School (HKS) Misinformation Review, 2021

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    We analyze the spread of Donald Trump’s tweets that were flagged by Twitter using two intervention strategies—attaching a warning label and blocking engagement with the tweet entirely. We find that while blocking engagement on certain tweets limited their diffusion, messages we examined with warning labels spread further on Twitter than those without labels. Additionally, the messages that had been blocked on Twitter remained popular on Facebook, Instagram, and Reddit, being posted more often and garnering more visibility than messages that had either been labeled by Twitter or received no intervention at all. Taken together, our results emphasize the importance of considering content moderation at the ecosystem level.