ABSTRACT
This chapter reviews evidence of giving behaviors that are not easily explained by purely self-interested preferences, a standard assumption in economics. It begins with observational evidence from the field, focusing on two major forms of generosity: philanthropy and tipping. The second half of the chapter turns to experimental evidence from three canonical games in the lab: the dictator game, ultimatum game, and public good game. An advantage of lab games is that it is possible to plausibly eliminate the self-interested incentives for generosity. The fact that individuals still demonstrate generosity towards others in these settings suggests that the assumption of pure self-interest is inadequate.
