The literature of private provision of public goods suggests that incentive to contribute is inversely related to group size. This paper empirically tests this relationship using field data from Chinese Wikipedia, an online encyclopedia. We exploit an exogenous reduction in group size as a...

We examined whether people conform to or diverge from the most popular choice among their friends by conducting a large-scale field experiment on a leading social-networking site in China. Our setting allowed us to minimize confounding effects such as pre-existing taste similarities between a...