Key Figures in the History of Economic Theory
Play Match the Economist to Their Theory →
Adam Smith (1723–1790)
A Scottish moral philosopher, born in Kirkcaldy and educated at Glasgow and Oxford, who held the chair of moral philosophy at Glasgow before spending years as a travelling tutor and then writing The Wealth of Nations (1776). His documented contributions are the analysis of the division of labour and its dependence on the extent of the market; the argument that specialisation and exchange, not stocks of gold, constitute national wealth; a sustained attack on mercantilist trade restriction and on the monopoly privileges of chartered companies; and the four maxims of taxation. The invisible hand is genuinely his, but it appears only three times across his entire published work and is far less central to his argument than its modern fame suggests. Smith was also sharply critical of merchants and manufacturers, writing that they seldom meet without the conversation ending in a conspiracy against the public.
David Ricardo (1772–1823)
A London stockbroker who made a substantial fortune in government securities, retired early, entered Parliament as member for Portarlington, and produced the most rigorously deductive economics of his century. His Principles of Political Economy and Taxation (1817) contains three ideas that survived him. Comparative advantage shows that two countries gain from trade even when one is absolutely more productive at everything, because what matters is the opportunity cost of production, not absolute productivity. Differential rent explains rent as arising from differences in land fertility rather than from any productive act by the landlord — a theory published almost simultaneously in 1815 by Ricardo, Malthus, Edward West and Robert Torrens, so priority is genuinely shared. The third is his method: the tightly specified model reasoned to a conclusion, which set the pattern for economic theory ever after.
Karl Marx (1818–1883)
A German philosopher, journalist and political organiser who spent his later decades in London working in the British Museum reading room. Volume one of Das Kapital appeared in 1867; Friedrich Engels edited volumes two and three from Marx's manuscripts after his death. Marx began from the classical labour theory of value he inherited from Ricardo and used it to build the concept of surplus value: the difference between the value labour produces and the wage it receives. From this he derived an account of capital accumulation, the reserve army of the unemployed, the tendency of the rate of profit to fall, and recurrent crisis. Mainstream economics abandoned his value-theoretic foundations within a decade of the book's publication, but his questions — about distribution, class, technological displacement, and instability as a normal feature rather than an accident — never left the field.
Alfred Marshall (1842–1924)
A Cambridge mathematician turned economist whose Principles of Economics (1890) was the standard textbook in the English-speaking world for roughly forty years. Marshall's achievement was reconciliation rather than revolution: he showed that the classical emphasis on cost of production and the marginalists' emphasis on utility were the two blades of a pair of scissors, neither of which cuts alone. Supply and demand determine price jointly, with the relative importance of each depending on the time period under consideration. He gave economics price elasticity of demand, consumer surplus, the market-period/short-run/long-run distinction, and the habit of confining mathematics to appendices so the argument stayed readable. He also gave it its most quoted self-definition: economics as the study of mankind in the ordinary business of life.
John Maynard Keynes (1883–1946)
A Cambridge economist, civil servant, journalist, investor and negotiator whose career spanned the Versailles conference and Bretton Woods. The Economic Consequences of the Peace (1919) made him famous by attacking the reparations imposed on Germany. A Tract on Monetary Reform (1923) contains his most quoted sentence, that in the long run we are all dead — a line about the uselessness of equilibrium reasoning during a crisis, and one that is very frequently miscredited to the General Theory. That later book (1936) is the substantive contribution: the argument that output, not price, does the adjusting when demand falls; the consumption function and the multiplier; liquidity preference as the determinant of the interest rate; and animal spirits as the driver of investment under irreducible uncertainty.