China overtakes us for most purchasing power

China overtook the U.S. last year as the world's biggest economy when measured in terms of purchasing power, according to Arvind Subramanian, senior fellow at the Peterson Institute for International Economics in Washington.

The size of China's economy in 2010 was $14.8 trillion, compared with the U.S.'s $14.6 trillion, when accounting for the countries' differing costs of living, Subramanian wrote in a note published yesterday, a week before President Hu Jintao visits Washington. So-called purchasing power parity calculates gross domestic product using exchange rates that adjusts for price differences of the same goods between nations.

Growth in the world's most populous nation has averaged 10.3 percent a year over the past decade, nearly six times faster than the U.S. China was the biggest auto market for the second year running, created the world's fastest supercomputer and was ranked the biggest user of energy in 2010.

A poll of Americans ahead of a summit of Hu and President Barack Obama next week, found some 47 percent said China is the leading economic power with 31 percent naming the U.S., according to the Washington-based Pew Research Center for the People and the Press. A February 2008 Pew Poll found 41 percent of Americans considered the U.S. the top economic power, with 30 percent naming China.