Friends Don't Let Friends Free Ride

Theory predicts that social sanctioning can solve the collective action problem, but only when people find out whether their peers participate. We evaluate this prediction using data from the near-universe of cell phone subscribers in Venezuela. Those whose behavior is more easily observed by peers are much more likely to protest and much more likely to sign a political petition than otherwise similar people in less-visible social network positions. Together with qualitative and survey data, we interpret this finding as evidence that social network structure can facilitate (or frustrate) social sanctioning as a solution to the collective action problem.