Individual Evolutionary Learning, Other-regarding Preferences, and the Voluntary Contributions Mechanism ∗ DRAFT Jasmina Arifovic † & John Ledyard ‡ March 30, 2009 Abstract The data from experiments with the Voluntary Contributions Mechanism suggest four stylized facts. To date, no theory explains all of these facts simultaneously. We provide a new theory by merging our Individual Evolutionary Learning model with a variation of other-regarding preferences and a distribution of types. The data generated by our model are remarkably similar to data from a variety of experiments. Further, the data generated do not seem to depend in any crucial way on the exact values of the parameters of our model. That is, we have a robust explanation for most behavior in VCM experiments. * We thank Olena Kostyshyna and Lilong Shi for their help in generating the simulations in this paper. We would also like to thank participants at the 2008 Econometric Society Summer Meetings, Pittsburgh; 14th International Conference on Computing and Finance, 2008, Paris; 2008 North-American ESA Conference, Tucson and the participants at the seminars at University of Amsterdam, June 2008; Paris 2 University, June 2008; and University of New South Wales, August 2008. † Simon Fraser University, arifovic@sfu.ca ‡ California Institute of Technology, jledyard@caltech.hss 1