Cash or Credit? The importance of reward medium and experiment timing in classroom preferences for fairness

The author conducts experiments examining fairness preferences (Andreoni and Miller, 2002) and compares cash versus extra credit points as the reward medium. Additionally, he explores the role that classroom experiment timing—over the course of a semester—can have on outcomes. The results show that subjects are just as rational, if not more so, when the motivation is class points rather than cash. Also, preference classifications show that subjects are significantly more likely to be Selfish (and less likely to be Utilitarian) when the experiment is conducted early in the academic semester. One possible explanation is that is that the ultimate value of an extra credit point is more uncertain early in the semester, thus leading risk-averse students to make more selfish experiment allocations.