People who identify themselves as conservatives donate money to charity more often than people who identify themselves as liberals. They donate more money and a higher percentage of their incomes.
It is not that conservatives have more money. Liberal families average 6 percent higher incomes than conservative families...
Conservatives not only donate more money to charity than liberals do, conservatives volunteer more time as well. More conservatives than liberals also donate blood.
According to Professor Brooks: "If liberals and moderates gave blood at the same rate as conservatives, the blood supply of the United States would jump about 45 percent."
While this sort of statistical data gives conservatives a chuckle, there are some that disagree with Brooks's conclusion. Jim Lindgren over at The Volokh Conspiracy says that Brooks is placing too much emphasis on the liberal vs. conservative divide.
(T)he contrast in Who Really Cares is frequently made between liberals (about 30% of the population) and conservatives (about 40% of the population), but I find that often the group that contrasts most strongly with conservatives is not liberals (who share with conservatives higher than average educations), but political moderates (about 30% of the population)...
This problem of treating liberals and conservatives (who share similar levels of education) as the outliers — when moderates often are the outliers — is a common one in conservatism research, whether that research is done by liberal or conservative researchers. Here it can make liberals look as if they are at the opposite end of the spectrum in donations from conservatives, but from the data that are presented by Brooks, it’s often hard to tell whether moderates (not liberals) really are the outliers.
I'm not really sure that any of these findings are that surprising. If you believe that it is the government's job and not the responsibility of individuals to take care of the poor and needy, then you probably don't feel as compelled to donate. On the other hand, if you think that individuals are responsible for aiding others, then you are more likely to donate your money, time, goods, even blood. It really is a world-view thing.
Lindgren doesn't dismiss Brooks's book, though. In this post he explains that the real significance to the information isn't between liberals and conservatives but between those who believe in redistribution of income from poor to rich and those that don't.
Compared to those favoring greater income redistribution, anti-redistributionists are more likely to report that they donated money to charities, religious organizations, and political candidates (p<.000000001). This hypothesized effect remains significant (p=.001) after controlling for race, gender, age, income, and education. Anti-redistributionists were also more likely to report having returned money after receiving too much change, and to have looked after plants, pets, or mail while someone was away. The one sort of altruistic behavior the redistributionists were more likely to engage in was giving money to a homeless person on the street. Thus, it appears that those who wanted the government to promote more income leveling were less likely to be generous themselves in their patterns of charitable donations and some other altruistic behaviors.
None of these findings is really surprising to me. As I said, it all depends on whose responsibility it is to take care of people.