Recent figures published by Giving USA show that in the U.S. charitable gifts of money have been 2% or more of GDP since 1998 and more than 89% of Americans donate to charity. Such figures have left fundraisers, who are typically long on rules of thumb and short on hard scientific evidence, divided as to the most efficient means to attract these dollars. Though the economics of charity has been well studied on the "supply" side, critical gaps remain on the "demand" side.

In an effort to better understand the economics of charity, we make use of a large-scale natural field experiment. Specifically, we use a direct mail solicitation to explore whether, and to what extent, "price" matters in charitable fundraising. To study this price effect, we test the impact of matching gifts; a leadership gift that is conditional committed by a donor(s) to match the contributions of others at a given rate.

We randomly assign a sample of over  50,000 prior donors to receive either a 1:1 match offer,  a 1:2 match offer (for each dollar donated, a lead donor will give two),  a 1:3 match offer, or to receive no match offer. The impact of this match is measuring both by the average amount donated and the likelihood of donation.