Reputation, personal identity and cooperation in a social dilemma

Abstract

Many problems of human society, such as overexploiting fish stock or the difficulty of sustaining the global climate, are problems of achieving cooperation. When individuals, groups or states are free to overuse a public good, they usually overuse it. Thus, public goods are at risk of collapsing, which happens to health insurance systems, fish stock and most probably the global climate (Hasselmann et al. 2003). This problem is known as the 'tragedy of the commons' (Hardin 1968, 1998). Social and political scientists, economists and recently evolutionary biologists have studied this issue intensively (e.g. Ledyard 1995, Ostrom 1999, Fehr & Fischbacher 2003, Nowak & Sigmund 2004). Several potential solutions to this social dilemma have been proposed and/or shown in experiments with human subjects: (i) punishment of uncooperative group members (Boyd & Richerson 1992, Gintis 2000, Sigmund et al. 2001, Fehr & Gächter 2000b, 2002), (ii) costly signaling with altruistic acts (Gintis et al. 2001), (iii) voluntary participation in the public goods game (Hauert et al. 2002, Semmann et al. 2003), (iv) a kind of interaction with both indirect reciprocity situations (see 14.3; Milinski et al. 2002a, Semmann et al. 2004, 2005) and a trust game (Barclay 2004). There are several examples from human societies where the social dilemma has been successfully avoided, at least for some time, by mechanisms such as control of access to public goods by the local community (Berkes et al. 1989). Nevertheless, tragedies of the commons are usually found to be tragedies.