Flick, Click, and Sick: Mental Health Risks of Short-video Platforms

This paper provides the first large-scale causal evidence on short-video platforms' mental health impacts. Leveraging unique city-level data on short-video app usage and individual panel data from a nationally representative survey (2010-2022), we exploit spatial variation in pre-2016 4G infrastructure interacted with individuals' pre-2016 mobile internet usage and Douyin's September 2016 launch as instrumental variables for short-video exposure. Results show that increased short-video exposure significantly deteriorates mental health, with effects equivalent to 80\% of unemployment's psychological impact. Vulnerable populations suffer disproportionately: Rural residents, youth, elderly, the poor, and those without secondary education, with rural left-behind elderly experiencing the most severe outcomes. Mechanism analysis reveals four channels driving these effects: Unfavorable social comparison and inequality perception, disrupted sleep and exercise patterns, declining physical health and (non-)cognitive abilities, and weakened family relationships. These findings highlight how digital innovation can exacerbate existing social inequalities through multiple psychological and behavioral pathways.