I haven’t read the report in enough detail to have an opinion about how good the research is. I suppose I could invoke the usual disclaimer about correlation not proving causality, but there’s something else that interests me, an angle that I haven’t seen in the news reports. According to an article on the Chronicle of Philanthropy’s website, “the study is based on exact dollar amounts released by the Internal Revenue Service showing the value of charitable deductions claimed by American taxpayers.”
So the study is about any form of tax-deductable giving, and makes no distinction between that which funds religious or political activities—such as preaching, proselytizing, or opposing evolution and gay marriage—and that which actually helps people with things like food, housing, or medical care. Religious believers fund both, but in what proportion?
This doesn’t lessen the generosity of the people giving the money, and there’s nothing wrong with funding institutions that exist mainly to promote your beliefs (as long as those beliefs aren’t harmful), but let’s not confuse that with our usual understanding of “charity.”