http://philanthropy.com/article/America-s-Generosity-Divide/133775/ http://philanthropy.com/article/America-s-Generosity-Divide/... It's actually a pretty comp

http://philanthropy.com/article/America-s-Generosity-Divide/133775/ http://philanthropy.com/article/America-s-Generosity-Divide/... It's actually a pretty comprehensive study, though this article doesn't cover everything discovered, it is still very much worth reading.