Developing economies now produce 41 percent of the world's output, up from 36 percent in 2000, according to the World Development Indicators 2008. The combined output of the world's economies reached $59 trillion in 2006. Using new measurements that take into account the differences in price levels between countries, China now ranks as the second largest economy in the world, and 5 of the 12 largest economies are developing economies.

Strong growth over the period has increased the shares of all developing regions except Latin America and the Caribbean, while the share of high-income economies fell by 5 percent.

This year's World Development Indicators (WDI) introduces new estimates of purchasing power parity (PPP). PPPs are used to convert local currencies to a common currency - in this case the US dollar. By taking account of price differences between countries on a broad range of products and services, PPPs allow more accurate comparisons of market size, the structure of economies, and what money can buy. The new PPPs replace previous benchmark estimates, many of them from 1993 and some dating back to the 1980s. These new estimates are based on the recently released results of the International Comparison Program (ICP) - a cooperative program involving 146 economies.

"We live in a world of highly interdependent markets for goods, services, finance, labor, and ideas," said Alan Gelb, Acting World Bank Chief Economist and Senior Vice President for Development Economics. "When we measure economies on a comparable global scale, the growing clout of developing countries comes into sharp relief."