Abstract Previous experimental and observational work suggests that people act more generously when they are observed and observe others in social settings. But the explanation for this is unclear. An individual may want to send a signal of her generosity in order to improve her own reputation....

When and how should a fundraiser ask for a donation from an individual facing an uncertain bonus income? A standard model of expected utility over outcomes predicts that the individual’s before choice – her ex-ante commitment conditional on her income – will be the same as her choice after...