Shedding Light into Preference Heterogeneity: Why Players of Traveller’s Dilemma Depart from Individual Rationality?

We analyse the experimental outcome of the Traveller's Dilemma under three different treatments - baseline (BT), compulsory ex post players' meeting (CET) and voluntary ex post players' meeting (VET) - to evaluate the effects of removal of anonymity (without preplay communication) in a typical one shot game in which there is a dilemma between individual rationality and aggregate outcome. We show that deviations from the Nash equilibrium outcome are compatible with the joint presence in the sample of individually rational, team-rational, (gift giving), "irrational" and (opportunistic) "one-shot-cooperator" types. The two main factors affecting deviations from the standard individually rational behaviour are male gender and the interaction of generalised trust with the decision of meeting the counterpart in the VET design.