Some rich countries are more unequal than others - and the United States more so than most. America has a higher degree of income inequality than almost any other developed country. Only three of the 34 members of the Organization for Economic Cooperation and Development rank higher - Chile, Mexico and Turkey. So why is the U.S. so much more unequal than its peers? The U.S. Congressional Research Service cited several potential reasons in a report earlier this year. One is that most other rich countries spend a bigger share of their national output on social programs, which tend to lessen income inequality. In Germany, public social spending accounted for 27.8 percent of gross domestic product in 2009, compared with 19.2 percent in the United States. A second factor is tax systems. A 2012 study by economists at the OECD found that, in general, the more a country spends on social programs, and the more progressive its tax-and-transfer system is, the more it can reduce income inequality. The U.S. is less effective at reducing inequality through taxes and benefits than the OECD average. Attitudes toward the poor may make a difference, some researchers say. A 2008 OECD study found that respondents in the United States and Korea were far more likely to say poor people were poor because they are lazy than did respondents in Nordic and Continental European countries. Recent studies ... have shown that Americans are now less likely to move into a class above their parents than are people in other rich countries.