We calculate the equilibrium fraction of cooperators in a population in which payoffs accrue from playing a single-shot prisoner's dilemma game. Individuals who are hardwired as cooperators or defectors are randomly matched into pairs, and cooperators are able to perfectly find out the type of a...

The current debate on trade liberalization is accompanied by an increased concern about environmental and food safety issues leading to frictions of different country groups under the World Trade Organization (WTO). This discussion paper aims at shedding more light on some of the issues in the...