From:http://online.wsj.com/article/SB126072304261489561.html

ByJUSTIN LAHARTandJON HILSENRATH

Paul A. Samuelson, whose analytical work laid the foundation for modern economics, died Sunday. He was 94.

Mr. Samuelson, the first American to win the Nobel Prize in economics and the author of one of the most-ubiquitous college textbooks ever, was "one of the greatest teachers that economics has ever known" and "a titan of economics," according to Federal Reserve chairman Ben Bernanke.

"Paul Samuelson was both a path-breaking and prolific economic theorist," said Mr. Bernanke, a former student of Mr. Samuelson's at the Massachusetts Institute of Technology.

Actively publishing into the 2000s, Mr. Samuelson's career in economics spanned eight decades. As a high school student in 1932, he wandered into an economics lecture at the University of Chicago and was enamored. But attending Chicago as an undergraduate during the Great Depression, he became acutely aware, he said in an interview with The Wall Street Journal earlier this year, of the differences between what was being taught in the classroom and "what I heard out the windows and I heard from the street."

In 1935 he went, despite his Chicago professors' protestations, to Harvard University for his graduate work. His 1941 PhD thesis, later published as "Foundations of Economic Analysis," examined the mathematical structure underlying economics. The approach revolutionized the field, to the point where economists today are often consumed with finding mathematical proofs for their theories.

"For me, it is a special bereavement," said Princeton University economist Avinash Dixit. "My whole style of research, and the techniques that support almost all of my own papers, derive from his foundational articles."

Mr. Samuelson started teaching at MIT in 1940, the beginning of a lifelong association with the university that helped its economics program become the most highly-regarded in the world. Through his "Economics" textbook, first published in 1948 and for years the most widely used college textbook on any topic, his analytical approach became the standard for undergraduate courses. It also introduced the work of John Maynard Keynes into the college curriculum. Now in its 19th edition, it is still popular. Mr. Bernanke keeps a copy signed by Mr. Samuelson on the shelves in his office at the Fed.

"There's just an enormous amount of what every undergraduate learns that we take for granted that Paul played an absolutely critical role in codifying and uncovering," said MIT economist and National Bureau of Economic Research president James Poterba, who remembers carrying around Mr. Samuelson's textbook as a high school student. "It's like trying to envision how did people do mechanics before Newton."

In 1970, Mr. Samuelson was the first American to win the Nobel Prize in economics, the second year the prize was offered. "Samuelson's contribution has been that, more than any other contemporary economist, he has contributed to raising the general analytical and methodological level in economic science," wrote the Nobel prize committee. "He has in fact simply rewritten considerable parts of economic theory."

Mr. Samuelson, a lifelong Democrat, acted as an adviser to Presidents John F. Kennedy and Lyndon B. Johnson, though he refused to take an official position in government. Mr. Samuelson hailed from a family of well-known economists, including brother Robert Summers, sister-in-law Anita Summers and nephew Lawrence Summers.

"Above all else, Paul Samuelson was a scholar," Lawrence Summers, who runs President Obama's National Economic Council,