Seasonal altruism: How Christmas shapes unsolicited charitable giving

Christmas is a holiday of Christian origin with traditions that emphasize prosocial behavior, including charitable giving, but does it actually make people more altruistic? Responding to this question poses a challenge because of the confounding factors of charitable tax breaks, reciprocity motives, pressure from the solicitors and persuasive campaigns for giving that are more prevalent in December. In this paper, I use a unique solicitation situation where these factors are eliminated. Based on nine years of data and more than 50 million giving decisions, I provide three main results. First, the month of December is associated with a 14% increase in the probability to make a donation, thereby providing strong support to the notion of seasonal altruism. Second, exploiting a reform that changed the price of giving, I find that this December effect is equivalent to a 32% discount on charitable giving. Finally, half of the December increase in generosity persists into January before returning to the baseline in February.