We investigate parochial altruism, the combination of in-group altruism and out-group hostility, in an experimental conflict game preceded by a prisoner’s dilemma. Our data are consistent with parochial altruism, but cannot be explained by in-group pro-sociality or out-group hostility alone.

To trust is to risk. When we lend someone money, we make ourselves vulnerable, hoping or expecting that the borrower will reward our trust and return the money at a later stage, possibly with interest or a reciprocal favor added. This paper examines whether willingness to trust follows the same...

We introduce two variants of the one-shot joy-of-destruction minigame (mini-JOD). Two players are endowed with the same amount of money. They simultaneously decide whether or not to reduce the payoff of the other player at an own cost. In one treatment there was a probability that Nature would...

In this study, we use an allocation experiment to study the effects of group identity and group size on in-group favouritism when the person's own payoff is not affected by her decision. In a triadic setting when subjects are asked to allocate a fixed amount of resource between two other...

We study how conflict in contest games is influenced by rival parties being groups and by group members being able to punish each other. Our motivation stems from the analysis of socio-political conflict. The theoretical prediction is that conflict expenditures are independent of group size and...

While numerous experiments demonstrate how pro-sociality can influence economic decision-making, evidence on explicitly anti-social economic behavior has thus far been limited. In this paper we investigate the importance of spite in experimental rent-seeking contests. Although, as we show,...

Understanding the proximate and ultimate sources of human cooperation is a fundamental issue in all behavioural sciences. In this article we review the experimental evidence on how people solve cooperation problems. Existing studies show without doubt that direct and indirect reciprocity are...

This paper employs experiments to determine how effectively arrangements decreasing the expected cost of trust betrayal foster trust in three Gulf countries (Kuwait, Oman and the United Arab Emirates), and two Western countries (Switzerland and the United States). Our basic instrument elicits...

We conducted a randomized field experiment to examine how workers respond to wage cuts, and whether their response depends on the wages paid to coworkers. Workers were assigned to teams of two, performed identical individual tasks, and received the same performance – independent hourly wage....

Social comparison has potentially far reaching consequences in many economic domains. We conducted a field experiment to examine how social comparison affects workers' effort provision if their own wage or that of a co-worker is cut. Workers were assigned to groups of two, performed identical...