As a commonwealth of the United States, Puerto Rico enjoys many benefits of the stable U.S. dollar, referred to as a "peso" by most local people, and the U.S. central banking structure. Economic trends tend to follow those on the mainland, and the dollar retains a relatively strong and stable monetary value. The monetary stability gives the island an advantage over many other Latin American countries. Puerto Rico's per capita income at purchasing power parity (an economic measure of the strength of a nation's currency) of US$9,800 (1999 est.) is one of the highest in all of Latin America, and the inflation rate is a relatively low 5.2 percent.