Imagine ten people each have \$1,000 to give to charity this year. They pool their money, and draw one of their names out of a hat. The winner gets to decide how to give away all \$10,000. This is an example of a donor lottery. More generally, a donor lottery is an arrangement where a group of people pool their money and pick one person to give it away. This selection is randomized so that each person has a probability of being selected proportional to their initial contribution.