In his Books & Culture article "A Lot of Lattés," Ron Sider reviews Passing the Plate: Why American Christians Don't Give Away More Money, a book "about the pitifully small charitable donations of the richest Christians in history." Sider offers a synopsis of some of the authors' findings:
If just the "committed Christians" (defined as those who attend church at least a few times a month or profess to be "strong" or "very strong" Christians) would tithe, there would be an extra 46 billion dollars a year available for kingdom work. To make that figure more concrete, the authors suggest dozens of different things that $46 billion would fund each year: for example, 150,000 new indigenous missionaries; 50,000 additional theological students in the developing world; 5 million more micro loans to poor entrepreneurs; the food, clothing and shelter for all 6,500,000 current refugees in Africa, Asia, and the Middle East; all the money for a global campaign to prevent and treat malaria; resources to sponsor 20 million needy children worldwide. [The conclusion of the authors] is surely right: "Reasonably generous financial giving of ordinary American Christians would generate staggering amounts of money that could literally change the world."
Twenty percent of American Christians (19 percent of Protestants; 28 percent of Catholics) give nothing to the church. Among Protestants, 10 percent of evangelicals, 28 percent of mainliners, 33 percent of fundamentalists, and 40 percent of liberal Protestants give nothing. The vast majority of American Christians give very little—the mean average is 2.9 percent. Only 12 percent of Protestants and 4 percent of Catholics tithe.
A small minority of American Christians give most of the total donated. Twenty percent of all Christians give 86.4 percent of the total. The most generous five percent give well over half (59.6 percent) of all contributions. But higher-income American Christians give less as a percentage of household income than poorer American Christians. In the course of the 20th century, as our personal disposable income quadrupled, the percentage donated by American Christians actually declined.