HOW do Latin America’s countries rank in terms of wealth? Whatever answer you have in mind is wrong, according to one measurement or another. Take GDP per capita: as of a few years ago, Brazil has been richer than Mexico. But if you account for purchasing power (that is, the amount of stuff people can buy in their country with the money they earn), Mexico jumps ahead. In Central America, Panama is about toovertake Costa Rica in terms of GDP per head (and already has in purchasing-power terms). But in terms of equality, it lags behind: poor Panamanians are worse off than poor Costa Ricans.