Having more money does not necessarily make a person more generous. According to an analysis of U.S. Bureau of Labor Statistics data, in 2007 the poorest one-fifth of Americans donated 4.3 percent of their incomes — more than double the percentage pledged by the nation's richest one-fifth, who gave just 2.1 percent of their incomes. There is no firm rule on donating, and every bit can help. Many people aspire to donate between 3 and 10 percent of their taxed incomes. Donors should just be sure they are able to cover bills and typical living expenses before giving to charity.