Today and tomorrow over a third of the world’s population (around 2 billion people) will be celebrating Christmas1. Traditionally, the holiday season will inevitably feature an exchange of gifts. The sums spent on Christmas gift-giving are huge! For example, in 2018 the expected spending on Christmas gifts in the United States is around 885 USD per person2 - this is about 2.8% of what someone in the middle of income distribution earns per year. If we work backwards from these figures and assume that a similar share of an average family’s income is devote...