China is set to overtake the U.S. as the world's number one economy, while India has jumped into third place ahead of Japan, according to a new study from the world's leading statistical agencies.
The 2011 International Comparison Program (ICP), which involves the World Bank, assesses economies based on purchasing power parity (PPP), an estimate of the real living costs. The results revealed on Wednesday paint a new and different picture of the global economy compared with the last update in 2005.
The research puts China's GDP (gross domestic product) at 87 percent of the U.S. in 2011 and says the Chinese and Indian economies have more than doubled relative to that of the U.S. In the 2005 study, the ICP believed China's economy was less than half the size of the U.S., at 43 percent.
"The United States remained the world's largest economy, but it was closely followed by China when measured using PPPs. India was now the world's third largest economy, moving ahead of Japan," the report said.
It added: "The results indicate that only a small number of economies have the greatest shares of world GDP. However, the shares of large economies such as China and India have more than doubled relative to that of the United States."
The ICP program is the largest global statistical operation, covering 199 economies from eight regions. It said that changes to its methodology help explain the estimates for the size of China's economy.
Rapid growth has led many economists to anticipate that China, the world's second biggest economy, would move into the number one position over the next few years. The latest findings from the ICP could fuel a debate on whether that is likely to happen sooner rather than later.
China's own National Bureau of Statistics, which took part in the study, said it had reservations about the study's methodology and didn't endorse the results as "official statistics," Reuters reported.
China's government has been reluctant to acknowledge previous milestones showing its economic rise when it passed Germany as the biggest exporter, Japan as the No. 2 economy and the United States as the biggest trader.
Its leaders have emphasized China's status as a middle-income country in resisting pressure to adopt binding limits on greenhouse gas emissions, for which their country is the biggest source.