Finding the right incentives for blood donation.

What form might this take? In 1967, the Italian government passed legislation that gave blood donors paid time off on the day of donation. Eligible donors include employees of private and public organizations, but not the self-employed, employers, or those without formal employment. The Italian government reimburses employers for the value of pay to eligible employees who donate blood.

In the six years preceding the law's passage, membership in the Italian Association of Blood Donors increased by 60,000 members. In the six years after the law's passage, membership increased by 170,000 members.

The average donation among the donors Lacetera and Macis studied was 2.4 times per year. Workers who experienced a switch in status from ineligible for the day off to eligible tended to increase their blood donations by one per year. Similarly, employees who became ineligible by leaving the work force or opting for self-employment ended up reducing the frequency with which they donated blood. The findings suggest that removing the incentive would reduce donations.

The public hospital in the study town accepted donations from 8 to 11 a.m., Monday through Saturday. Not surprisingly, people who were not eligible for the paid day off tended to cluster donations during their free time on Saturday mornings.

Eligible employees tended to cluster blood donations on Friday. An eligible Friday morning donor gets a paid day off and, after donating, a Friday afternoon of leisure. What's more, most people do not work on Saturday or Sunday, so they end up with two and a half consecutive days of leisure time after donating on a Friday morning—more than they could get by donating on any other day of the week. Eligible employees not only responded favorably to the blood donation incentive, they did so in a way that maximized their material gain from donating.

The economists also observed a substantial subset of hard-core altruists: eligible employees who consistently donated during their normal time off on Saturday mornings rather than taking the paid leave. Apparently, the promise of paid time off is strong enough to lure additional donations but appropriate enough to avoid offending too many of the Saturday donors who draw on intrinsic motivations for giving blood. So while it pays to donate blood in Italy, the payment is masked in a way that avoids commercializing the transaction, allowing people to feel rewarded for their donations even if their motivations weren't entirely altruistic.