Gift exchange experiments have demonstrated that norms can affect labor market outcomes and provided an explanation for involuntary unemployment. However, conflicting results from laboratory and field experiments have questioned the relevance of gift exchange and helped spark an ongoing debate...

In three sets of experiments involving 5,432 subjects, we show that agents make more errors when doing so allows them to justify selfish behavior. We show that errors relating to addition arise when they can help to justify selfishness but are eliminated when selfish motives are removed. In...