Princeton economist and New York Times columnist Paul Krugman won the Nobel economics prize on Monday for his analysis of how economies of scale can affect trade patterns and the location of economic activity.
Krugman was the lone of winner of the $1.4 million award and the latest in a string of American researchers to be honored.
The Royal Swedish Academy of Sciences praised Krugman for formulating a new theory to answer questions about free trade.
"What are the effects of free trade and globalization? What are the driving forces behind worldwide urbanization? Paul Krugman has formulated a new theory to answer these questions," the academy said in its citation.
"He has thereby integrated the previously disparate research fields of international trade and economic geography," it said.
The award, known as the Nobel Memorial Prize in Economic Sciences, is the last of the six Nobel prizes announced this year and is not one of the original Nobels. It was created in 1968 by the Swedish central bank in Nobel's memory.
In addition to his work as an economist at Princeton University in New Jersey, where he has been since 2000, Krugman also writes about politics and inequality in the United States and other topics for The New York Times.