This paper provides the first evidence of the existence of gender-based favoritism in life saving decisions to donate blood. We conduct a field experiment among blood donors from Bosnia and Herzegovina where we exogenously manipulate the signal of a blood recipient's gender by adding his/her name, and photograph, to a letter soliciting blood donation.
Motivated by the literature on identity, we test the influence on donation behavior of two dimensions of shared identity between donor and recipient - gender and age. 74% more blood donors donate if the potential blood recipient is of the same gender. This result is mostly driven by male donors donating to a male recipient.
In contrast to gender identity being an important determinant in fostering donors' participation rates, being of similar age to the blood recipient has relatively little effect. By identifying an important factor that influences willingness to give blood, our results have implications for better targeting of campaigns to increase blood donations.