The debate surrounding the use of monetary incentives to encourage altruistic behavior, particularly blood donation, is ongoing. Some argue that paying blood donors could backfire, potentially diminishing the intrinsic motivation of voluntary donors – a phenomenon known as motivational crowding-out. Concerns also exist about the potential for decreased blood quality if financial incentives attract donors who might conceal health risks to obtain payment.
A comprehensive meta-analysis was conducted to investigate the cost-effectiveness of offering monetary incentives, including cash payments and material rewards, for blood donation. This study encompassed observational studies, natural experiments, and field experiments to provide a robust analysis.
Our search identified an initial pool of 17 relevant studies. Following a rigorous screening process for relevance and quality, 8 studies were selected for in-depth analysis. These studies were then evaluated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system to assess the quality of evidence, yielding 12 estimates of the marginal donation rate associated with monetary incentives.
The combined analysis, utilizing a random-effects model, indicated a marginal donation rate of 0.4 additional blood units collected per 1000 inhabitants annually for each dollar of incentive offered. However, it’s important to note that this estimate exhibited considerable variation across studies, reflecting the diverse contexts and perceived costs for donors in different settings. A more focused analysis, restricted to the most reliable and homogenous studies, yielded a higher estimate of 1.0 additional blood units per 1000 inhabitants per year per dollar incentive.
From a cost perspective, our findings suggest that implementing donor payments adds between $22 and $121 to the cost of increasing the blood supply by a single unit of whole blood. This cost range is significantly influenced by the specific context and local conditions.
Crucially, the observed positive marginal donation rate associated with donor payments does not support the concern of a short-run crowding-out effect. In fact, the data suggests that monetary incentives can be effective in increasing blood donations, at least in the short term.
However, it is important to acknowledge the limitations of the current research. The available studies are not designed to evaluate potential long-term crowding-out effects, negative spillover effects on other prosocial behaviors or altruistic norms, or the risks of transmittable infectious diseases. Therefore, the question of whether monetary incentives represent the most cost-effective and ethically sound strategy for enhancing blood and plasma supply remains unanswered and requires further investigation.
