In a fun coincidence, this Red Cross drive, offering a $5 Amazon gift card in exchange for presenting as a blood donor came across my Facebook feed this morning. I say it is a coincidence, because my Taboo Trades seminar was reading about precisely this issue today, in “Rewarding Altruism? A Natural Field Experiment” by Nicola Lacetera, Mario Macis, and Robert Slonim. The authors conduct a natural field experiment involving nearly 100,000 individuals on the effects of offering economic incentives for blood donations. Because cash compensation is not permitted, subjects received either a $5, $10, or $15 gift card. As is the case with the Red Cross drive featured here, anyone presenting to donate would receive the gift cards regardless of whether they donated. (Presumably, to undermine any incentive to lie about health histories in order to receive the compensation, as suggested long ago by Titmuss — who we read last week).
Lacetera, Macis, and Slomin find that providing material rewards led to a large and significant increase in the propensity to donate, and in a very standard way: the effect was increasing in the amount of the incentives. They also found that rewards led to some spatial (i.e. some subjects who would have donated at a particular center switched to a center offering a gift card) and short-term inter-temporal displacement (i.e. some subjects who would have donated later moved up the timing of their donations in order to take advantage of the reward offer). But the gift cards increased the likelihood of donation, even after accounting for these displacement effects.
Interestingly, the current drive is offering a $5 incentive, but the optimal incentive in the study, if I recall correctly, was $10 (although $15 generated more donations, it also cost more and resulted in more displacement effects). That’s my recollection anyway.
So, give blood! And, for the moment anyway, earn money! (Oops, not money, a mere thank you gift, of course).