Benjamin Mako Hill and Aaron Shaw
Abstract Online communities like Wikipedia produce valuable public information goods. While some of these communities require wouldbe contributors to create accounts, many do not. Does this requirement catalyze cooperation or inhibit participation? Prior research provides divergent predictions but little causal evidence. We conduct an empirical test using longitudinal data from 136 natural experiments where would-be contributors to wikis were suddenly required to log in to contribute. Requiring accounts leads to a small increase in account creation, but reduces both high and low quality contributions from registered and unregistered participants. Although the change deters a large portion of low quality participation, the vast majority of deterred contributions are higher quality. We conclude that requiring accounts introduces an under-theorized tradeoff for public goods production in interactive communication systems.