That's the prediction of a new report out today by the World Bank, which says the global economy could expand from $35 trillion last year to $72 trillion in 2030.
It says this will have a big impact on global poverty, saying the number of people living on less than $1 a day could be cut in half -- from 1.1 billion to 550 million in 2030.
"Developing countries are likely to grow from about a fifth of the global economy to a third of the global economy, depending on how you measure it," said Richard Newfarmer, the report's lead authoer. "In terms of purchasing power, they may amount to about half or more of the global economy by 2030. So this is a very important segment of the international market."
However, the report goes on to warn that the gap between rich and poor could widen in many countries.