How Effective are Reminders and Frames in Incentivizing Blood Donations

This paper studies the effects of reminders, and frames used to invoke higher levels of empathy and altruistic motives on the willingness to donate blood. We have conducted a randomized field experiment with 3236 blood donors from Bosnia and Herzegovina, in order to test how effective frames were when used in letters soliciting blood donation. Further, we tested the effectiveness of the letter itself which served as a specific reminder, making the need for blood more salient. Our baseline group did not receive any letter. Another seven groups received letters which differed in terms of goal framing; whether a specific victim was identified; and the gender of a victim. We found that a reminder of the need for blood in the form of a simple letter increases the probability of coming to donate blood by 63% relative to the baseline group, suggesting that reminder letters may serve as a cost effective policy tool. At the same time, we found that the framing of the letter had relatively little effect when donors are allowed longer period to make their donation decision.