Theses Doctoral

The Impact of Social Media on Political Elites

Argote Tironi, Pablo Francisco

The Internet and social media have significantly affected democracies around the world. Yet, little is known about their direct impact on political elites. My dissertation posits that the expansion of the internet and social media has increased elite ideological extremism through two channels: i) A growth in voter radicalism, affecting politicians who respond to their constituencies, and ii) a higher reward to extreme politicians on social media. In particular, politicians' higher exposure to a very politicized set of voters and the positive reception of their negative messages on social media results in an increase in their ideological extremism.

I test these hypotheses in Chile, conducting four types of analyses. I start by characterizing the profile of the social media and Facebook users in Chile at different periods, corroborating that they are people with sharper ideological preferences than the rest of the voters.

Then, I examine whether Chilean members of the Chamber of Deputies pay more attention to Facebook when an increasing share of their constituencies have access to 3G mobile internet. Empirically, I estimate a two-way fixed effect model, regressing measures of Facebook activity ---likes, shares, and total interactions--- on 3G mobile internet coverage using a panel data of Chilean legislators. Here, I found a substantive effect of 3G mobile internet on Facebook activity among politicians, implying that when citizens have more access to the internet, legislators spend much more time interacting on Facebook.

Moreover, I analyze if either district-level access to the internet or large levels of Facebook activity enhances the level of ideological extremism among political elites. The use of behavioral outcomes outside the digital world is crucial to understanding the impact of social media on democracies, as such outcomes can have real-world consequences. I decided to use roll-call voting data from the Chilean congress, which allowed me to generate a measure of ideological extremism on the left-right scale. I regressed the measure on several measures of Facebook activity and/or 3G coverage, using two-way fixed effects models and an instrumental variable specification, leveraging the variation in 3G mobile internet as an instrument. In these analyses, I consistently found that higher levels of Facebook interactions increase ideological extremism among Chilean politicians, especially in the initial years of Facebook penetration.

This dissertation contributes to the literature in three ways. First, it is one of the few academic endeavors investigating how social media affect political elites in domains outside the digital world. Second, this work speaks to the old discussion about whether politicians lead or follow the public, in this case, regarding extremism. My results show an elite-driven move to extremism due to exposure to social media, regardless of the position of voters.

Third, this analysis contributes to the understanding of polarization and democratic backsliding in the global south. Indeed, in the last years, Latin American countries such as Colombia, Peru, Brazil, and Chile have experienced increasing levels of elite polarization, as evidenced by the type of candidates disputing the presidential elections. Social media penetration is a plausible driving force behind this phenomenon, as it encourages politicians to spend time chasing "likes," which, as I demonstrate, could eventually have consequences for the functioning of democracy.

Geographic Areas


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More About This Work

Academic Units
Political Science
Thesis Advisors
Marshall, John L.
Ph.D., Columbia University
Published Here
April 5, 2023