To say or not to say: the mediating role of psychological safety and self-efficacy on the influence of social capital on users' knowledge sharing behavior in social network sites

The prevalence of the computer-mediated environment and the Internet have led to the emergence of social network sites. Social network sites have not only changed the way people communicate and share knowledge with one another, but have also created socialnomics and social commerce. Previous studies on social networks have focused on user behavior and mostly adopted an exploratory approach. In contrast, this article develops a holistic model that incorporates three facets of social capital (structural, cognitive, and relational) as determinants of users' knowledge sharing behavior and examines the mediating roles of users' psychological safety and knowledge sharing self-efficacy. The proposed structural equation model is empirically tested with survey data from 439 Facebook users in Taiwan. The results show that cognitive social capital exerts the strongest positive impact on Facebook users' knowledge sharing behavior and that knowledge sharing self-efficacy indeed plays a mediating role. The findings provide important insights for both theory and practice.