American economist Paul Krugman on Monday won the 2008 Nobel prize for economics for work that helps explain why some countries dominate international trade.

Here are some key facts on the winner and the prize:

* The Royal Swedish Academy of Sciences said the prize recognised Krugman’s formulation of a new theory to answer questions such as what is driving worldwide urbanisation.

* Krugman’s work has integrated the previously disparate research fields of international trade and economic geography, the prize committee said.

* His new theory sheds light on why global trade is dominated by countries that not only have similar conditions, but also trade in similar products.

* Krugman has criticised the administration of President George W. Bush for policies that he argues led to the current financial crisis.

* Krugman’s theories have helped explain how self-reinforcing processes of urbanisation and increased large-scale production, as well as higher real wages and a more diverse supply of goods, can combine to divide regions into a high-technology urbanized core and a less developed periphery.

* Krugman was born in New York City in 1953 and received a PhD at the Massachusetts Institute of Technology.

* He has been professor of economics and international affairs at Princeton University, New Jersey, since 2000.

* Krugman has written for publications such as the New York Times and Foreign Affairs and is the author of 20 books and more than 200 papers in professional journals.

* He has also taught at Yale, MIT and Stanford University.

* His current work centres on economic and currency crises.