When awarding the prize in 1970, the Swedish Royal Academies stated that he "has done more than any other contemporary economist to raise the level of scientific analysis in economic theory".

Samuelson wrote a weekly column for Newsweek magazine along with Chicago School economist Milton Friedman, where they represented opposing sides: Samuelson, as a self described "Cafeteria Keynesian",[7] claimed taking the Keynesian perspective but only accepting what he felt was good in it.

[7] The lecture mentioned as the cause was on the British economist Thomas Malthus, who most famously studied population growth and its effects.

[13] Samuelson felt there was a dissonance between neoclassical economics and the way the system seemed to behave; he said Henry Simons and Frank Knight were a big influence on him.

As a graduate student at Harvard, Samuelson studied economics under Joseph Schumpeter, Wassily Leontief, Gottfried Haberler, and the "American Keynes" Alvin Hansen.

[13] James M. Poterba, an economics professor at MIT and the president of the National Bureau of Economic Research, commented that Samuelson "leaves an immense legacy, as a researcher and a teacher, as one of the giants on whose shoulders every contemporary economist stands".

Samuelson strongly criticised Friedman and Friedrich Hayek, arguing their opposition to state intervention "tells us something about them rather than something about Genghis Khan or Franklin Roosevelt.

Several years later, Samuelson responded with David Ricardo's theory of comparative advantage: "That it is logically true need not be argued before a mathematician; that is not trivial is attested by the thousands of important and intelligent men who have never been able to grasp the doctrine for themselves or to believe it after it was explained to them.

One article included Samuelson's most quoted remark and a favorite economics joke: To prove that Wall Street is an early omen of movements still to come in GNP, commentators quote economic studies alleging that market downturns predicted four out of the last five recessions.

[36]In the early editions of his famous, bestselling economics textbook Paul Samuelson joked that GDP falls when a man "marries his maid".

The book showed how these goals could be parsimoniously and fruitfully achieved, using the language of the mathematics applied to diverse subfields of economics.

The book proposes two general hypotheses as sufficient for its purposes: The first tenet suggests that all actors, whether firms or consumers, are striving to maximize something.

They could be attempting to maximize profits, utility, or wealth, but it did not matter because their efforts to improve their well-being would provide a basic model for all actors in an economic system.

[39] Samuelson was also influential in providing explanations on how the changes in certain factors can affect an economic system.

It shows how to represent (in the maximization calculus) all real-valued economic measures of any belief system that is required to rank consistently different feasible social configurations in an ethical sense as "better than", "worse than", or "indifferent to" each other (p. 221).

"[42] Written in the shadow of the Great Depression and the Second World War, it helped to popularize the insights of John Maynard Keynes.

The study of business cycles along with the introduction of the Keynesian approach of aggregate demand set the stage for the macroeconomic revolution in America, which then diffused throughout the world through translations into every major language.

[50] Piling on, William F. Buckley, Jr., in his 1951 book, God and Man at Yale, devoted an entire chapter, attacking both Samuelson's and Tarshis' textbooks.

Stanley Fischer (1987, p. 234) writes that taken together they are "unique in their verve, breadth of economic and general knowledge, mastery of setting, and generosity of allusions to predecessors".