British economist, member of the Cambridge circle that surrounded John Maynard Keynes in the 1930s, and by the judgment of many of her peers the most important woman economist of the 20th century — a figure who was repeatedly denied the Nobel Prize in ways that her contemporaries regarded as unmistakably gendered. Robinson was educated at Girton College, Cambridge, and spent essentially her entire career there, first as a fellow at Newnham and eventually as Professor of Economics. She was central to the genesis of Keynes's General Theory (1936), to which she contributed both in argument and in the simplification of key formulations for publication.
Her own early book The Economics of Imperfect Competition (1933), written in parallel with Edward Chamberlin's similar work, displaced the assumption of perfect competition from the center of microeconomics by working out the theory of markets in which firms face downward-sloping demand curves and exercise some degree of market power. The book established her reputation before she was thirty. Her Essay on Marxian Economics (1942) was an unusual project for a non-Marxist economist — a serious technical engagement with Marx's economic analysis, sympathetic where she thought he was right and unsparing where she thought he was wrong — that helped reopen respectable economic conversation with the Marxist tradition in the English-speaking world.
Her major theoretical work was The Accumulation of Capital (1956), the central post-Keynesian account of long-run growth and income distribution, and her role in the Cambridge Capital Controversy of the 1960s and 1970s — the technical dispute with neoclassical economists at MIT (Samuelson, Solow) over whether "capital" could be coherently aggregated into a single quantity that earned a return equal to its marginal product. The Cambridge (England) side, led by Robinson and Piero Sraffa, won the technical argument decisively; the neoclassical side, as Robinson memorably observed, went on teaching as though nothing had happened. Her later writing — Economic Philosophy (1962), Contributions to Modern Economics (1978) — became increasingly impatient with an economics profession she regarded as ideologically captured and intellectually evasive. Amartya Sen was among her students and acknowledged her as a formative influence.