President Obama’s proposal to limit the tax break wealthy people get for charitable deductions in order to help fund a universal healthcare system in the US has given rise to much debate about how much giving is affected by tax breaks. One question is whether all charities would feel the pain equally, or just those in certain fields.

A recently published paper by Robert and Michelle Yetman at the University of California suggests that in the US tax incentives have little or no effect on donations to charities in the fields of health, human services, or public and social benefit, but they do influence giving to organizations devoted to animals, arts and culture, education and the environment, as well as to private foundations.