Working Paper: CEPR ID: DP15642
Authors: Adrian Bruhin; Lorenz Goette; Simon Haenni; Lingqing Jiang
Abstract: We test whether asking individuals to donate blood leads to a persistent change in prosocial behavior, and what the underlying mechanisms are. In a large-scale field experiment, we randomize asking blood donors to turn out, and follow them over up to 18 months. We observe significant behavioral persistence over at least one year. We use naturally occurring rainfall as a second instrument for donor turnout to test whether persistence is due to habit formation (Stigler and Becker, 1977) or a persistent increase in motivation independent of past donation. Our results strongly favor habit formation as the underlying mechanism.
Keywords: prosocial behavior; habit formation; field experiment; natural experiment
JEL Codes: C93; D04; D91; C36
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| phone call leads to persistent increases in donation rates (D64) | primarily through habit formation (D91) |
| phone call affects future motivation (L96) | violates exclusion restriction (C20) |
| asking donors to commit to donating blood (D64) | significant and persistent increase in donation rates (D64) |