Take the annual income of the wealthiest 20 percent, divide it by the annual income of the poorest 20 percent, and you get a number. The larger a country’s number is, the more economically unequal the country is.
Here is Latin America. The United States (wealthiest 20% earns 16 times more than the poorest 20%) is now in the middle of the pack. In 1980, the U.S. number was 10.5.
The source is the UN Economic Commission for Latin America and the Caribbean annual Statistical Yearbook, which was released January 10. All numbers are for 2011, except Bolivia (2009), El Salvador (2010), Guatemala (2006), Honduras (2010), and Nicaragua (2009). The U.S. figure comes from Census Bureau data cited by Congressional Research Service [PDF].