Virtual communities enable one to pretend to be a different person or to possess a different identity at little or no cost. Despite the ubiquity of such communities, there is limited theoretical and empirical research on how taking on a different identity is associated with one's contributive behavior in those communities. Drawing on the social psychology literature, we adopt the concept of self-discrepancy rooted in self-identity and derive an index for selfdiscrepancy by using the differences between actual and virtual self-identities. Next, we link the selfdiscrepancy with perceived privacy rights and with the quality and quantity of contribution. An analysis of 299 respondents showed that self-discrepancy significantly influenced perceived privacy rights and indirectly reduced quality and quantity of contribution in virtual communities. Furthermore, sub-group analysis revealed that the effects of self-discrepancy varied depending on whether the virtual community was utilitarian or hedonic.