Data released by the World Bank on April 30 shows that the United States is on the verge of losing its status as the world's largest economy, and its economic size is likely to fall behind China this year. If so, this overtaking would come earlier than widely expected. Since surpassing Britain in 1872, the United States has always been the world's largest economy. Most economists had previously predicted that China's economy would surpass that of the United States in 2019.

　　The above data were compiled by the World Bank's International Comparison Program (ICP), the most authoritative estimate of the purchasing power of currencies in different countries, and are used by most public and private sector institutions, including the International Monetary Fund (IMF). This is the first update of the data since 2005. After extensive research on the prices of goods and services, the World Bank concluded that the purchasing power of currencies in poorer countries is stronger than previously expected, and therefore raised the relative size of emerging market economies.

　　As an estimate of the real cost of living, purchasing power parity (PPP) is recognized as the best way to compare the size of economies, and is preferable to volatile exchange rates, which rarely reflect the true cost of goods and services. Based on exchange rate indicators, the IMF estimated that US gross domestic product (GDP) was $16.2 trillion in 2012, while China's GDP was $8.2 trillion.

　　In 2005, the World Bank believed that China's economy was less than half the size of the United States, at only 43% of the US level. Using the new PPP method and taking into account the fact that China's economy has grown significantly faster than that of the United States in recent years, the World Bank study concluded that China's GDP reached 87% of that of the United States in 2011. For 2011, the World Bank report said: "The United States remains the world's largest economy, but measured by purchasing power parity, China is close behind." The IMF expects China's economy to have grown by 24% from 2011 to 2014, while the United States grew by only 7.6%, so China's economy is likely to surpass that of the United States this year.

　　These data have completely changed the picture of the global economic landscape and increased the importance of large middle-income countries. India was previously the world's tenth-largest economy and has now become the third-largest. In 2005, India's economy was 19% the size of that of the United States, and by 2011 it reached 37%, nearly doubling that ratio. Russia, Brazil, Indonesia and Mexico have all entered the top 12 of the global economy. By contrast, because of high costs and low growth, Britain and Japan have fallen further behind the United States in the rankings compared with 2005, Germany's relative position has risen slightly, and Italy has maintained its original ranking. This result will intensify the debate over voting rights at global international institutions such as the World Bank and the IMF, which are increasingly out of step with the global balance of economic power.

　　When examining actual per capita consumption, the report found that the new method, together with the fact that poor countries are growing faster, has led to a "substantial reduction" in the gap between rich and poor, "showing that the world has become more equal." The GDP of the world's rich countries still accounts for 50% of global GDP, while their population accounts for only 17% of the global population. After comparing the cost of living in different countries, the report also found that the four economies with the highest cost of living in the world are Switzerland, Norway, Bermuda and Australia, and the lowest are Egypt, Pakistan, Myanmar and Ethiopia.