Assessing the Impact of Granular Privacy Controls on Content Sharing and Disclosure on Facebook
基于2009年12月Facebook隐私政策变化，研究发现细粒度隐私控制总体上增加了用户公开分享（如发帖）并减少了私密交流（如私信），但不同隐私敏感度的用户反应相反，最终缩小了用户间的行为差异。
We examine the role of granular privacy controls on dynamic content-sharing activities and disclosure patterns of Facebook users based on the exogenous policy change in December 2009. Using a unique panel data set, we first conduct regression discontinuity analyses to verify a discontinuous jump in context generation activities and disclosure patterns around the time of the policy change. We next estimate unobserved effects models to assess the short-run and long-run effects of the change. Results show that Facebook users, on average, increase use of wall posts and decrease use of private messages after the introduction of granular privacy controls. Also, users’ disclosure patterns change to reflect the increased openness in content sharing. These effects are realized immediately and over time. More importantly, we show that user-specific factors play crucial roles in shaping users’ varying reactions to the policy change. While more privacy sensitive users (those who do not reveal their gender and/or those who have exclusive disclosure patterns ex ante) share more content openly and less content secretly than before, less privacy sensitive users (those who reveal their gender and/or those who have inclusive disclosure patterns ex ante) share less content openly and more content secretly after the change. Hence, the policy change effectively diminishes variation among Facebook users in terms of content-generation activities and disclosure patterns. Therefore, characterizing the privacy change as a way to foster openness across all user categories does not reveal the change’s true influence. Although an average Facebook user seems to favor increased openness, the policy change has different impacts on various groups of users based on their sensitivity to privacy, and this impact is not necessarily toward increased openness. To our knowledge, this is the first study that relies on observational data to assess the impact of a major privacy change on dynamic content-sharing activities and the resulting disclosure patterns of Facebook users.