Social identity, group composition and public good provision: an experimental study

Social fragmentation has been identified as a potential cause for the under-provision of public goods in developing nations, as well as in urban communities in developed countries such as the U.S. We study the effect of social fragmentation on public good provision using laboratory experiments. We create two artificial social groups in the lab and we assign subjects belonging to both groups to a public good game. The treatment variable is the relative size of each social group, which is a proxy for social fragmentation. We find that while higher social fragmentation leads to lower public good provision, this effect is short-lived. Furthermore, social homogeneity does not lead to higher levels of contributions.