Explaining Private Provision of Public Goods by Conditional Cooperation- An Evolutionary Approach -

We adopt an evolutionary approach to investigate whether and when condi-tional cooperation can explain the voluntary contribution phenomenon oftenobserved in public goods experiments and in real life. Formally, conditionalcooperation is captured by a regret parameter describing how much an in-dividual regrets to contribute less than the average. We find that the evolu-tionary stability of conditional cooperation depends on what is known aboutthe (individual) regret parameters of other group members.