We experimentally investigate the effects of two different sources of heterogeneity – capability and valuation – on the provision of public goods when punishment is possible or not. We find that compared to homogeneous groups, asymmetric valuations for the public good have negative effects on cooperation and its enforcement through informal sanctions. Asymmetric capabilities in providing the public good, in contrast, have a positive and stabilizing effect on voluntary contributions. The main reason for these results is the different externalities contributions have on the other group members’ payoffs affecting individuals’ willingness to cooperate. We thus provide evidence that it is not the asymmetric nature of groups per se that facilitates or impedes collective action, but that it is rather the nature of asymmetry that determines the degree of cooperation and the level of public good provisionThis network project brings together economists, psychologists, computer and complexity scientists from three leading centres for behavioural social science at Nottingham, Warwick and UEA. This group will lead a research programme with two broad objectives: to develop and test cross-disciplinary models of human behaviour and behaviour change; to draw out their implications for the formulation and evaluation of public policy. Foundational research will focus on three inter-related themes: understanding individual behaviour and behaviour change; understanding social and interactive behaviour; rethinking the foundations of policy analysis. The project will explore implications of the basic science for policy via a series of applied projects connecting naturally with the three themes. These will include: the determinants of consumer credit behaviour; the formation of social values; strategies for evaluation of policies affecting health and safety. The research will integrate theoretical perspectives from multiple disciplines and utilise a wide range of complementary methodologies including: theoretical modeling of individuals, groups and complex systems; conceptual analysis; lab and field experiments; analysis of large data sets. The Network will promote high quality cross-disciplinary research and serve as a policy forum for understanding behaviour and behaviour change.

Experimental data. The underlying decision situation behind our experiment is a standard linear public goods game. Subjects are randomly assigned to one of three experimental treatments, which differ with respect to the group members’ characteristics. In each treatment, participants are matched into groups of three, playing the public goods game for twenty consecutive periods with a surprise restart after ten periods. Group composition is kept constant across all twenty periods using a partner-matching design. At the beginning of each period, all group members receive an endowment of 20 tokens. During the first ten periods of the experiment, the game only consists of a contribution stage in which participants simultaneously decide how many tokens of their endowment they want to contribute to the public good and how many tokens they want to keep for themselves. In the last ten periods, the contribution stage is followed by a decentralized punishment stage.