"Are moderate drinkers more likely to give to charity? A worthy question, so I did a bit of analysis and found that, indeed, moderate drinkers tend to be more charitable than nondrinkers. For example, 54% of nondrinkers contribute to charity each year, giving away an average of $1,100. In contrast, 62% of those who take one to two drinks per day have an average annual giving level of $1,200. The alcohol effect has diminishing returns, however: Just 40% of people drinking five or more drinks per day are donors, and they give only $230 per year on average. (So once you get past two or three, you have to stop claiming you're 'doing it for a good cause.')"

Source (for WSJ subscribers only. Art Brooks notes as well that drinkers give $50 to $100 more each year to charity even after controlling for income, education and religion. "But stop at two and don't forget to write the check," he concludes.