Why Do People Volunteer? An Experimental Analysis of Preferences for Time Donations

We conduct a laboratory experiment to test if there are differences in behavior when subjects can donate either time or money to charity. Our subjects perform an effort task to earn money. In one condition they can have their efforts accrue to a charity instead of themselves. In other conditions subjects may only earn money for their private account but then donate it to a charity. We vary the timing and availability of donation opportunities in the monetary donation settings to test the impact of subtle solicitation pressure. We find that subjects with a more opportunities to donate will donate more often and in larger amounts. Further, subjects giving effort to charity give far more than subjects who give monetary donations - between two and five times as much, on average. We posit that this difference is driven by different warm glow from the two donation types.