User Location Disclosure Fails to Deter Overseas Criticism but Amplifies Regional Divisions on Chinese Social Media

We examine the behavioral impact of a user location disclosure policy implemented on Sina Weibo, China's largest microblogging platform, using a high-frequency, real-time dataset of uncensored user engagement with 165 leading government and media accounts. Leveraging a natural experiment result from the platform's sudden rollout of location tagging on April 28, 2022, we compare millions of time-stamped observations of user behavior in the comment sections of these accounts before and after the policy change. Although the policy appeared intended to deter overseas users from spreading information deemed harmful by the regime, we find no reduction in their engagement. Instead, the policy sharply reduced domestic users' willingness to comment on posts about local issues outside their own provinces. This effect was especially pronounced among out-of-province commenters and disproportionately curtailed criticisms. Using large language models, we further show that location disclosure triggered a rise in regionally discriminatory replies, which in turn heightened the perceived risk of cross-provincial engagement and reshaped the norms of online participation. Our findings suggest that authoritarian regimes can reinforce censorship not only through top-down control, but by mobilizing social cleavages, here, regional divisions, to suppress dissent and fragment public discourse.