Researchers have found heavy-tailed distributions in many phenomena, from the frequency of words to the sizes of cities. And they've even been found in how people give money to charity, such as how people responded with donations after the 2004 tsunami.

In a new paper posted to the arXiv, researchers at the University of Vermont decided to compare the patterns in giving to several different types of institutions: educational, health care, the arts, and more. And they found distinctive differences, between institutions and the types of institutions.

We find that the detailed forms of gift-size distributions differ across but are relatively constant within charity categories. We construct a model for how a donor's income affects their giving preferences in different charity categories, offering a mechanistic explanation for variations in institutional gift-size distributions.

Read the full research article by William L. Gottesman, Andrew James Reagan, Peter Sheridan Dodds about impact giving trends from Cornell University