Canadian-born economist who managed to synthesize divergent economic viewpoints. He was one of the more important economists of the post-World War II era, with a published output that dwarfed those of his contemporaries and made substantial contributions to the fields of macroeconomics and international trade.

Johnson earned numerous degrees. He studied at the University of Toronto (B.A., 1943; M.A., 1947), the University of Cambridge (B.A., 1946; M.A., 1951), Harvard University (M.A., 1948; Ph.D., 1948), and the University of Manchester (M.A., 1960). His teaching career was equally peripatetic: Johnson started with a lectureship at Cambridge (1949–56), become professor of economics at Manchester (1956–59), and moved to the University of Chicago as a professor of economics (1959–77). Later in his career, he held full professorships at two major institutions: the University of Chicago, where he was the Charles F. Grey Professor of Economics (from 1974), and the London School of Economics (from 1966 until his resignation in 1974).

One of the most prolific and readable economists of all time, Johnson published largely on topics of international trade, international finance, and monetary policy. In trade (international trade), one of Johnson's major theoretical contributions was his proof that a country could, under special circumstances, improve its situation with an import tariff even if other countries retaliated against it. Johnson realized that this scenario was unlikely, though, and remained an advocate of free trade, often delivering lectures that criticized Canada's trade barriers. In international finance, Johnson showed that growth in a country's money supply can strongly affect that country's balance of payments. Earlier, economists had focused on nonmonetary factors, but Johnson's 1958 article started what is now called the monetary approach to the balance of payments. In monetary theory, he synthesized Keynesianism (and its focus on economic demand) with monetarism (and its focus on supply-side economics). Johnson was hired by the University of Chicago to be the university's token “Keynesian,” but he became increasingly sympathetic to the Chicago monetarist viewpoint.

In his 30-year career, Johnson wrote 526 professional articles and 41 books and pamphlets. He died with 18 papers in proof, which prompted economist Paul Samuelson (Samuelson, Paul) to comment, “That is dying with your boots on!” The previous year, Johnson had been named an Officer of the Order of Canada.