Check out this interactive map from The Chronicle of Philanthropy. What intrigues me at first blush is that the darker areas (greater percentage of giving) seems to overlap areas of the United States where you will find more strongly held religious beliefs within the general population.
Does that mean that religious people are more generous? Probably too little data to draw a conclusion, but worth exploration.
Below is a link to a Pew Research web page that shows the United States and location of various stages of religious belief, as compiled from a religious landscape survey (click on image to go to website). There does seem to be strong overlap.
Does it count donations to their own church? Because those are charitable organizations, but donations to an organization from which you benefit isn’t quite the same as, say, just giving money that will help strangers.
That is an intriguing observation, and one that I wondered about. I’m fairly confident that this model included giving to one’s own church; however, I might suggest that donations to one’s church isn’t strictly (or solely) “an organization from which you benefit.” Many (most?) churches support mission work, whether local, national, or international, and not just the pastor’s salary and the heat for the building. That would be no different from donations to an arts organization that (1) has a building and staff (2) has members and (3) benefits the community, would it?