The Impact of the General Data Protection Regulation (GDPR) on Online Usage Behavior
Privacy regulations aim to safeguard consumers, but can have unintended consequences on how users interact with websites. This article estimates the causal effect of the EU's General Data Protection Regulation (GDPR) on online usage behavior and decomposes it into usage frequency (unique visitors) and usage intensity (visits per unique visitor). Using a generalized synthetic control estimator across trillions of visits to 6,387 websites in 24 industries and 13 countries-11 months before and 19 months after enforcement-it compares observations subject to the GDPR (EU users or EU websites) with unaffected observations (non-EU users on non-EU websites). Weekly visits decline by 4.88% within 3 months and by 10.02%% after 18 months, with the decline increasingly driven by usage frequency: by 18 months, unique visitors decline by 6.61%, whereas visits per unique visitor decline by only 0.59%. The average conceals offsetting effects consistent with a reallocation of online activity: about one quarter of websites gain significantly, and among websites losing users, the remaining users engage more intensively, whereas intensity falls where user numbers grow. Losses concentrate among hedonic and smaller websites and continue to deepen during the first wave of data-protection enforcement actions rather than being concentrated around the GDPR compliance deadline. Taken together, these patterns are more consistent with restricted data-driven user acquisition and privacy salience, than with consent friction and degraded retention as persistent explanations. Long-horizon, decompositional evaluation thus reveals GDPR's differential effect on usage frequency/intensity and heterogeneous effects not distinguished by the aggregate traffic effects reported in prior work.