Middle-income people gave more to charities in 2008 than wealthy people, and those in Republican-leaning states gave more than those in Democratic states, a new study by the Chronicle of Philanthropy finds.

The South is first among four regions studied by the Chronicle, giving an average of 5.2 percent of discretionary income to charity, compared with 4.1 percent in the Northeast.

Religious involvement plays a major role in charitible giving: When only donations to secular charities are counted, the Northeast leads, giving 1.4 percent of discretionary income to the South's 0.9 percent. (See the second PDF displayed to the right of this story's text.)

The charitable giving data is searchable down to the ZIP code level in the Chronicle of Philanthropy's interactive map.

Out of 28,725 zip codes nation-wide, 30306 ranked 1,598 with $19.9 million in donations.

Zip code 30307 ranked 2,437 with $15.1 million in donations.

Among the study's other key findings:

• The top eight states for charitable giving in 2008 voted for John McCain for president. Georgia ranks eight on the overall list. (See the PDF displayed to the right of this story.)
• People who earned $50,000 to $70,000 a year gave an average of 7.6 percent of their discretionary income to charity, compared with 4.6 percent for people who made more than $100,000.
• States that offer tax incentives for charitible giving can increase total donations, often at no cost to the donor when the state provides dollar-for-dollar tax credits.

What do you think of the study's findings? How much do you give to charity? Tell us in the comments.