Social Ties and User-Generated Content: Evidence from an Online Social Network

We use variation in wind speeds at sur…ng locations in Switzerland as plausibly exogenous shifters of users’propensity to post content about their sur…ng activity onto an online social network. We exploit this variation to test whether users’online content generation activity a¤ects their social ties, and whether ties in turn a¤ects content generation. Under weak monotonicity assumptions, we also estimate nonparametric bounds on these e¤ects. Economically signi…cant e¤ects of the type above can produce positive feedback that generates local network e¤ects in content generation. When quantitatively signi…cant, the increased content and tie density arising from the network e¤ect induces more visitation and browsing on the site, which fuels growth by generating advertising revenue. We …nd evidence for such network e¤ects.