Funding a new bridge in rural Vietnam: a field experiment on social influence and default contributions

Public goods provision is essential for economic development. Yet there is limited evidence regarding contributions to local public goods in developing countries. This article analyses a field experiment where all 200 households in a village in rural Vietnam make real contributions to a public good that is very important for them in daily life—a bridge. We study the role of social influence (that people may be more willing to co-operate if others do) and the effects of the default alternative in the choice situation. We find significant and substantial (in the order of magnitude of 15–25%) effects of both social influence and defaults but only when providing low reference or default contributions.