Impact of Short-Form Videos on Screentime and Sleep: Evidence from TikTok

Short-form video platforms have become central to debates about digital overuse and sleep disruption, yet causal evidence on their behavioral impacts remains limited. We study the effects of adopting short-form video in the context of TikTok, which pioneered the format and accounts for a large share of global short-form video consumption. Using granular smartphone touchstream data from a large opt-in panel of U.S. Android users, we track app usage, screen time, and inferred sleep behavior before and after TikTok adoption. We employ a difference-in-differences framework leveraging a high-frequency app usage data set from nearly 7,000 TikTok adopters. Our findings reveal a significant increase in overall screen time—averaging 221 minutes per week for heavy TikTok users—following TikTok adoption, alongside notable declines in usage of other social media and gaming apps, suggesting a strong substitution effect. The screen time effects are highest during late night hours. We also observe shifts in sleep patterns, including delayed bedtimes and a moderate reduction in sleep duration, among high-intensity users. We observe no effects for low-intensity users, who engage minimally with TikTok postadoption. Our findings show that short-form video adoption expands total digital attention rather than merely reallocating it, with important implications for platform design, regulation, and digital well-being. As a side result, our analysis provides clear evidence of substitutability between TikTok and traditional social media platforms, which has important implications for competition policy. This paper was accepted by D. J. Wu, information systems. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2024.08260 .