In a haystack-type representation of a heterogeneous population that is evolving according to a payoff structure of a prisoner’s dilemma game, migration is modeled as a process of “swapping” individuals between heterogeneous groups of constant size after a random allocation fills the...

This paper analyzes the effects of a legislative provision that grants a one-day paid leave of absence to blood donors who are employees in Italy. The analysis is based on a unique dataset with the complete donation histories of the blood donors in an Italian town. The cross-sectional variation...

Using longitudinal data on the entire population of blood donors in an Italian town, we examine how donors respond to an award scheme which rewards them with "medals" when they reach certain donation quotas. Our results indicate that donors significantly increase the frequency of their donations...