SHANGHAI'S economy is projected to grow the strongest among the top 30 cities globally by 2025, PricewaterhouseCoopers LLP said yesterday in a research report.

The city is set to rise from 25th to 9th place in the global city rankings in terms of gross domestic product from 2008 to 2025, PwC said. Shanghai's economy is projected to top US$692 billion in terms of purchasing power parity, the accounting firm said.

Purchasing power parity calculations eliminate the differences in foreign exchange and price levels between countries.

"Global economic activity is concentrated in the world's largest cities," said John Hawksworth, head of macro-economics at PwC. "Looking ahead to 2025, the study sees the rise of the emerging economy cities continuing."

He said the comparison is stark between the top emerging and the top advanced economy cities in terms of growth momentum.

Between 2008 and 2025, cities such as Shanghai, Beijing and Mumbai are projected to grow at about 6 to 7 percent per annum in real terms, whereas New York, Tokyo, Chicago and London are set to grow only at around 2 percent annually on average.

Shanghai has jumped into the top 30 tier with its strong growth between 2005 and 2008, PwC said. In 2008, Beijing ranked 38th while Guangzhou in south China ranked 44th.

In 2008, the total number of emerging economy cities in the top 100 was 39, with 61 in the advanced economies. In 2025, this gap is projected to narrow sharply with 48 of the top 100 cities in the emerging economies and 52 in the advanced economies.

The largest 100 cities accounted for 30 percent of the global economy in 2008.