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...

How does priming identity affect charitable giving? We show that individuals are more likely to donate when a facet of their identity associated with a norm of generosity is primed in an appeal. In large charitable giving field experiments run by the American Red Cross, appeals that prime an...

We examine how reciprocity changes over time by studying a large quasiexperiment in the field. Specifically, we analyze administrative data from a university hospital system. The data include information about over 18,000 donation requests made by the hospital system via mail to a set of its...