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. By the 1950s, Keynesian policies were adopted by almost the entire developed world and similar measures for a mixed economy were used by many developing nations. By then, Keynes's views on the economy had become mainstream in the world's universities. Throughout the 1950s and 1960s, the developed and emerging free capitalist economies enjoyed exceptionally high growth and low unemployment. Professor Gordon Fletcher has written that the 1950s and 1960s, when Keynes's influence was at its peak, appear in retrospect as a golden age of capitalism. In late 1965 Time magazine ran a cover article with a title comment from Milton Friedman (later echoed by US President Richard Nixon), "We are all Keynesians now". The article described the exceptionally favourable economic conditions then prevailing, and reported that "Washington's economic managers scaled these heights by their adherence to Keynes's central theme: the modern capitalist economy does not automatically work at top efficiency, but can be raised to that level by the intervention and influence of the government." The article also states that Keynes was one of the three most important economists who ever lived, and that his General Theory was more influential than the magna opera of other famous economists, like Adam Smith's The Wealth of Nations. Multiplier The concept of multiplier was first developed by R. F. Kahn in his article "The relation of home investment to unemployment" In the economic journal of June 1931. Kahn multiplier was the employment multiplier while as Keynes took the idea from Kahn and formulated the investment multiplier. Keynesian economics out of favour 1979–2007 Keynesian economics were officially discarded by the British Government in 1979, but forces had begun to gather against Keynes's ideas over 30 years earlier. Friedrich Hayek had formed the Mont Pelerin Society in 1947, with the explicit intention of nurturing intellectual currents to one day displace Keynesianism and other similar influences. Its members included the Austrian School economist Ludwig von Mises along with the then young Milton Friedman. Initially the society had little impact on the wider worldaccording to Hayek it was as if Keynes had been raised to sainthood after his death and that people refused to allow his work to