Participation in and provision of public goods: does granularity matter?

We use public goods games to experimentally investigate the effect of granularity (i.e., the degree of divisibility of the space of feasible contribution options) on participation (whether individuals contribute or not to the public good) and public goods provision (total contribution to the public good). Our results show that granularity has a significant effect on participation, mainly when coarser granularity eliminates the possibility of small contributions. However, this change in participation does not lead to a significant change in the total provision of the public good. These results are aligned with other experimental field results obtained in the context of donations and fundraising.