Crowding Out in Blood Donation: Was Titmuss Right?

In his seminal 1970 book, The Gift Relationship, Richard Titmuss argued that monetary compensation for donating blood might crowd out the supply of blood donors. To test this\nclaim we carry out a field experiment with three different treatments. In the first treatment subjects are given the opportunity to become blood donors without any compensation. In the second treatment subjects receive a payment of SEK 50 (≈ $7) for becoming blood donors, and in the third treatment subjects can choose between a SEK 50 payment and donating SEK 50 to charity. The results differ markedly between men and women. For men the supply of blood donors is not significantly different among the three experimental groups. For…