Syracuse University professor Arthur C. Brooks has written a book called Who Really Cares: The Surprising Truth About Compassionate Conservatism. His conclusions echo all of the other research I’ve seen:
The book’s basic findings are that conservatives who practice religion, live in traditional nuclear families and reject the notion that the government should engage in income redistribution are the most generous Americans, by any measure.
Conversely, secular liberals who believe fervently in government entitlement programs give far less to charity. They want everyone’s tax dollars to support charitable causes and are reluctant to write checks to those causes, even when governments don’t provide them with enough money.
[L]iberals give less than conservatives in every way imaginable, including volunteer hours and donated blood.
Liberals tend to specialize in giving away other peoples’ money.