Global real GDP would grow by 3.5 percent annually on average, making the world economy two-thirds bigger in 2020 than it was in 2005, said the study conducted by Economist Intelligence Unit (EIU) and the U.S.-based Cisco Systems, a worldwide leader in networking for the Internet.

The study said that China would be responsible for a significant 27 percent of this growth.

The study projected that the continued rapid growth of China would match the US as the world's largest consumer market in purchasing power parity (PPP) terms by 2020.

The study showed that by the year 2020 China, India and the US will jointly contribute 1 trillion US dollars to the global economy.

"The next fifteen years will see significant outpacing by Asia and particularly the powerhouses of China and India of the rest of the world in gross domestic product (GDP), wages and consuming power," the study said.

China and India would contribute 65 million and 142 million new workers to the global workforce, respectively, by 2020, said the study.

Despite this significant new workforce entering the market, wages would increase substantially, with wages in China in 2020 expected to be 4.5 times higher than they are presently, according to the study.

The study surveyed 1,656 executives from 100 countries and conducted in-depth interviews with executives, analysts and policymakers in late 2005.