John Maynard Keynes, 1st Baron Keynes 5 June 1883 – 21 April 1946), was a British economist whose ideas fundamentally changed the theory and practice of macroeconomics and the economic policies of governments. He built on and greatly refined earlier work on the causes of business cycles, and is widely considered to be one of the most influential economists of the 20th century and the founder of modern macroeconomics.His ideas are the basis for the school of thought known as Keynesian economics and its various offshoots.

In the 1930s, Keynes spearheaded a revolution in economic thinking, challenging the ideas of neoclassical economics that held that free markets would, in the short to medium term, automatically provide full employment, as long as workers were flexible in their wage demands. He instead argued that aggregate demand determined the overall level of economic activity and that inadequate aggregate demand could lead to prolonged periods of high unemployment. According to Keynesian economics, state intervention was necessary to moderate “boom and bust” cycles of economic activity.Keynes advocated the use of fiscal and monetary policies to mitigate the adverse effects of economic recessions and depressions.

Early life and education

John Maynard Keynes was born in Cambridge, Cambridgeshire, England, to an upper-middle-class family. His father, John Neville Keynes, was an economist and a lecturer in moral sciences at the University of Cambridge and his mother Florence Ada Keynes a local social reformer. Keynes was the first born, and was followed by two more children – Margaret Neville Keynes in 1885 and Geoffrey Keynes in 1887. Geoffrey became a surgeon and Margaret married the Nobel Prize-winning physiologist Archibald Hill.

According to the economist and biographer Robert Skidelsky, Keynes’s parents were loving and attentive. They remained in the same house throughout their lives, where the children were always welcome to return. Keynes would receive considerable support from his father, including expert coaching to help him pass his scholarship exams and financial help both as a young man and when his assets were nearly wiped out at the onset of Great Depression in 1929. Keynes’s mother made her children’s interests her own, and according to Skidelsky, “because she could grow up with her children, they never outgrew home”.


In October 1906, Keynes’s Civil Service career began as a clerk in the India Office.He enjoyed his work at first, but by 1908 had become bored and resigned his position to return to Cambridge and work on probability theory, at first privately funded only by two dons at the university – his father and the economist Arthur Pigou. By 1909 Keynes had published his first professional economics article in the Economics Journal, about the effect of a recent global economic downturn on India. He founded the Political Economy Club, a weekly discussion group. Also in 1909, Keynes accepted a lectureship in economics funded personally by Alfred Marshall. Keynes’s earnings rose further as he began to take on pupils for private tuition. On being elected a fellow in 1911 Keynes was made editor of The Economic Journal. By 1913 he had published his first book, Indian Currency and Finance.He was then appointed to the Royal Commission on Indian Currency and Finance – the same topic as his book – where Keynes showed considerable talent at applying economic theory to practical problems. His written work was published under the name “J M Keynes”, though to his family and friends he was known as Maynard.(His father, John Neville Keynes, was also always known by his middle name).

First World War

The British Government called on Keynes’s expertise during the First World War. While he did not formally re-join the civil service in 1914, Keynes travelled to London at the government’s request a few days before hostilities started. Bankers had been pushing for the suspension of specie payments – the convertibility of banknotes into gold – but with Keynes’s help the Chancellor of the Exchequer (then Lloyd George) was persuaded that this would be a bad idea, as it would hurt the future reputation of the city if payments were suspended before it was absolutely necessary.

In the 1920s

Keynes had completed his A Treatise on Probability before the war, but published it in 1921.The work was a notable contribution to the philosophical and mathematical underpinnings of probability theory, championing the important view that probabilities were no more or less than truth values intermediate between simple truth and falsity. Keynes developed the first upper-lower probabilistic interval approach to probability in chapters 15 and 17 of this book, as well as having developed the first decision weight approach with his conventional coefficient of risk and weight, c, in chapter 26.

Second World War

During the Second World War, Keynes argued in How to Pay for the War, published in 1940, that the war effort should be largely financed by higher taxation and especially by compulsory saving (essentially workers lending money to the government), rather than deficit spending, in order to avoid inflation. Compulsory saving would act to dampen domestic demand, assist in channelling additional output towards the war efforts, would be fairer than punitive taxation and would have the advantage of helping to avoid a post war slump by boosting demand once workers were allowed to withdraw their savings.


After the war, Keynes continued to represent the United Kingdom in international negotiations despite his deteriorating health. He succeeded in obtaining preferential terms from the United States for new and outstanding debts to facilitate the rebuilding of the British economy.

Just before his death in 1946, Keynes told Henry Clay, a professor of social economics and advisor to the Bank of Englandof his hopes that Adam Smith’s ‘invisible hand’ can help Britain out of the economic hole it is in: “I find myself more and more relying for a solution of our problems on the invisible hand which I tried to eject from economic thinking twenty years ago.”


Keynesian ascendancy 1939–79

From the end of the Great Depression to the mid-1970s, Keynes provided the main inspiration for economic policy makers in Europe, America and much of the rest of the world.While economists and policy makers had become increasingly won over to Keynes’s way of thinking in the mid and late 1930s, it was only after the outbreak of World War II that governments started to borrow money for spending on a scale sufficient to eliminate unemployment. According to the economist John Kenneth Galbraith (then a US government official charged with controlling inflation), in the rebound of the economy from wartime spending, “one could not have had a better demonstration of the Keynesian ideas.”

Neo-Keynesian economics

In the late 1930s and 1940s, economists (notably John Hicks, Franco Modigliani, and Paul Samuelson) attempted to interpret and formalise Keynes’s writings in terms of formal mathematical models. In what had become known as the neoclassical synthesis, they combined Keynesian analysis with neoclassical economics to produce neo-Keynesian economics, which came to dominate mainstream macroeconomic thought for the next 40 years.

Reception and views


Keynes’s economic thinking only began to achieve close to universal acceptance in the last few years of his life. On a personal level, Keynes’s charm was such that he was generally well received wherever he went – even those who found themselves on the wrong side of his occasionally sharp tongue rarely bore a grudge.Keynes’s speech at the closing of the Bretton Woods negotiations was received with a lasting standing ovation, rare in international relations, as the delegates acknowledged the scale of his achievements made despite poor health.

As a man of the centre described by some as having the greatest impact of any 20th-century economist,Keynes attracted considerable criticism from both sides of the political spectrum. In the 1920s, Keynes was seen as anti-establishment and was mainly attacked from the right. In the “red 1930s”, many young economists favoured Marxist views, even in Cambridge,and while Keynes was engaging principally with the right to try to persuade them of the merits of more progressive policy, the most vociferous criticism against him came from the left, who saw him as a supporter of capitalism.

Personal life


Keynes’s early romantic and sexual relationships were exclusively with men.Keynes had been in relationships while at Eton and Cambridge; significant among these early partners were Dilly Knox and Daniel Macmillan. Keynes was open about his affairs, and from 1901 to 1915 kept separate diaries in which he tabulated his many sexual encounters.Keynes’s relationship and later close friendship with Macmillan was to be fortunate, as Macmillan’s company first published his tract Economic Consequences of the Peace.


In 1921, Keynes wrote that he had fallen “very much in love” with Lydia Lopokova, a well-known Russian ballerina and one of the stars of Sergei Diaghilev’s Ballets Russes.In the early years of his courtship, he maintained an affair with a younger man, Sebastian Sprott, in tandem with Lopokova, but eventually chose Lopokova exclusively.They married in 1925, with Keynes’s former lover Duncan Grant as best man.”What a marriage of beauty and brains, the fair Lopokova and John Maynard Keynes” was said at the time. Keynes later commented to Strachey that beauty and intelligence were rarely found in the same person, and that only in Duncan Grant had he found the combination.The union was happy, with biographer Peter Clarke writing that the marriage gave Keynes “a new focus, a new emotional stability and a sheer delight of which he never wearied”.


Keynes was ultimately a successful investor, building up a private fortune. His assets were nearly wiped out following the Wall Street Crash of 1929, which he did not foresee, but he soon recouped. At Keynes’s death, in 1946, his net worth stood just short of £500,000 – equivalent to about £11 million ($16.5 million) in 2009. The sum had been amassed despite lavish support for various good causes and his personal ethic which made him reluctant to sell on a falling market, in cases where he saw such behaviour as likely to deepen a slump.

Political causes

Keynes was a lifelong member of the Liberal Party, which until the 1920s had been one of the two main political parties in the United Kingdom, and as late as 1916 had often been the dominant power in government. Keynes had helped campaign for the Liberals at elections from about 1906, yet he always refused to run for office himself, despite being asked to do so on three separate occasions in 1920. From 1926, when Lloyd George became leader of the Liberals, Keynes took a major role in defining the party’s economics policy, but by then the Liberals had been displaced into third party status by the Labour Party.


Throughout his life, Keynes worked energetically for the benefit both of the public and his friends; even when his health was poor, he laboured to sort out the finances of his old college. Helping to set up the Bretton Woods system, he worked to institute an international monetary system that would be beneficial for the world economy. Keynes suffered a series of heart attacks, which ultimately proved fatal. They began during negotiations for the Anglo-American loan in Savannah, Georgia, where he was trying to secure favourable terms for the United Kingdom from the United States, a process he described as “absolute hell”.A few weeks after returning from the United States, Keynes died of a heart attack at Tilton, his farmhouse home near Firle, East Sussex, England, on 21 April 1946, at the age of 62.