Paul Samuelson: The Economist's Economist

How Paul Samuelson brought mathematics into economics, wrote its best-selling textbook, and helped define public goods and the modern theory of trade.

Paul Samuelson (1915 to 2009) was one of the most influential economists of the twentieth century. In 1970, he became the first American to win the Nobel prize in economics.

Maths in economics

Samuelson’s 1947 book Foundations of Economic Analysis showed how mathematics could unify economic theory. Many ideas that had been expressed in words became precise models. Modern economics, with its equations and graphs, owes much to him.

The textbook

In 1948, Samuelson published Economics, an introductory textbook. It became the best-selling economics textbook of all time, going through many editions and translations and teaching millions of students worldwide. He reportedly said he didn’t care who wrote a nation’s laws if he could write its economics textbooks.

The neoclassical synthesis

Samuelson combined Keynesian ideas about recessions and government policy with neoclassical ideas about markets. In this neoclassical synthesis:

In the short run, Keynesian policies can fight unemployment.
In the long run, when the economy is at full employment, markets allocate resources efficiently.

This view dominated economics for decades after World War Two.

Public goods

In 1954, Samuelson gave a precise definition of public goods: goods that are non-rival, so one person’s use doesn’t reduce another’s. He showed why markets underprovide them, supporting a role for government.

Trade theory

The Stolper-Samuelson theorem (1941, with Wolfgang Stolper) showed that trade can raise the incomes of some groups, such as owners of abundant factors, while lowering others’. It helps explain why trade creates winners and losers within countries.

Legacy

Samuelson trained generations of economists at MIT, which became a leading economics department. His approach of rigorous models tested against evidence remains central.

The textbook in the classroom

A student in the 1970s opening an introductory economics course, whether in Boston or Delhi, might well have used Samuelson's textbook. Its diagrams of supply and demand and the circular flow shaped how millions first learned economics.

Thinking mathematics is the whole of economics

Samuelson made maths central, but he also stressed that models must be judged by how well they explain the real world.

Key takeaways

Samuelson brought mathematics to the core of economic theory.
His textbook Economics became the best-selling in the field.
He developed the neoclassical synthesis of Keynesian and market ideas.
He defined public goods and co-created the Stolper-Samuelson theorem.