Gísli Gylfason

Gísli Gylfason

Gísli Gylfason

PhD candidate in economics
Paris School of Economics & EHESS

I am a PhD candidate in economics at the Paris School of Economics and EHESS, supervised by Ekaterina Zhuravskaya. In 2024–25 I was a visiting PhD student in the Department of Politics at Princeton University, hosted by Jacob N. Shapiro.

My main research interests are Political Economics and Media Economics. In particular, my research investigates how new information technologies shape news demand, political beliefs and behaviour, and mental health. I use quasi-experimental methods on large-scale administrative and behavioural data.

I am on the economics job market in 2026–27.

References Ekaterina Zhuravskaya · Jacob N. Shapiro · Oliver Vanden Eynde

Job Market Paper

Doomscrolling: TikTok and News Consumption

Draft available upon request.

Using device-level mobile use data and a novel instrument for TikTok use, I find that TikTok use substantially reduces news consumption around major news events such as elections. Survey evidence shows the effect extends beyond mobile devices: TikTok use also decreases traditional news consumption, political knowledge, and increases partisan polarization in presidential approval.

Full abstract

How does TikTok use affect news consumption? Leveraging detailed device-level mobile browsing and app use data and a shock to early adoption of TikTok as a novel, plausibly exogenous source of variation, I estimate the causal effect of TikTok use on news consumption, political knowledge and attitudes in the United States. I find that increased TikTok use substantially reduces news consumption related to major news events such as elections, national disasters and major political developments. TikTok use causes decreases in news consumption along both the extensive and intensive margins. It also reduces the length of individuals’ news consumption sessions, suggesting that reduced attention spans contribute to the effect. Survey evidence shows that the effect is not limited to mobile devices and has downstream consequences. Individuals in high-TikTok-use media markets have lower traditional news consumption and political knowledge, and higher partisan polarization in presidential approval after, but not before, TikTok’s proliferation.

All research →