Short-form video platforms drive mobile overuse

Short-form video platforms, such as TikTok, have rapidly transformed digital media consumption, with billions of active users worldwide. Their design features, such as algorithmic personalization, endless scrolling, and rapid novelty, have raised concerns about mobile overuse and its associated adverse effects on well-being. However, evidence on whether short-form videos increase mobile usage remains limited. To address this gap, we estimate the causal effect of short-form video platforms on mobile usage behavior using individual-level data (N=1,764) drawn from a representative panel of U.S. mobile device users. Specifically, we compare TikTok adopters to adopters of Instagram/Facebook during the period when short-form video was the key distinguishing feature of TikTok (i.e., before these competitors introduced their own short-form video products), thereby shedding light on the effect of exposure to short-form videos. We find that using short-form video platforms significantly increases total mobile usage duration (up to 17%) and reduces average time away from the mobile phone (by -20%), but does not consistently affect the number of daily sessions. Effects are disproportionately higher among individuals who previously used their phones less, relative to those with higher baseline usage. Contrary to fears about nocturnal overuse, effects are only significant during daytime hours. Surprisingly, older individuals have significantly larger increases in mobile sessions per day from usage of short-form video platforms compared to younger individuals. Altogether, our results show a behavioral mechanism through which short-form video platforms contribute to mobile overuse, offering new insights into theories of digital addiction and highlighting the importance of promoting healthier digital engagement.