Like the monetarist Milton Friedman, Keynes looked to price stability as a way to shore up classical economic thinking. For the most part, he believed, laissez-faire economics worked. Supply and demand did bring society to a prosperous equilibrium. They just needed a few pieces of basic economic architecture to work: property rights, the rule of law, and price stability. But unlike Friedman, Keynes had arrived at monetarism as a creative way to expand the power of the state to fight the uncertainties and anxieties of postwar life.

Keynes’s design was in favour of the liberalization of the economy and the capital’s transfers, for the main purpose of monetary stability. To avoid devaluation of currencies - a practice followed by governments in order to sustain their export - Lord Keynes planned to introduce “Bancor”, a money of account to be accepted by all countries in international exchanges. The international body to be organized would get interests both from debtor and creditor countries, in order to finance the balance of payments system (p. 130).

Keynes did not challenge the efficacy of price adjustment mechanisms in clearing particular markets in the Marshallian partial equilibrium theory on which he had been reared. He did challenge the mindless application of those mechanisms to economy-wide markets. Founding what came to be known as macroeconomics, he was modeling a whole economy as a closed system. He knew he could not use the Marshallian assumption that the clearing of one market could be safely described on the assumption that the rest of the economy was unaffected.

Hayek may still have lessons to teach us. The policies he recommended during the Great Depression may have been badly flawed but his insight that prosperity cannot be restored by unending expansion of debt may have some value at a time when the limits of “Keynesian” quantitative easing are becoming clear. It is in any case far from obvious that Keynes would have supported a continuation of QE once a disastrous collapse had been averted. “Keynesianism” is a confection of Keynes’s more mechanical disciples, not an indication of how this mercurially brilliant mind would have responded to our present dilemmas. Again, Hayek’s claim that nothing can be done to mitigate the impact of free markets on social cohesion was dangerously misguided. But he was right to point out that capitalism cannot be remodelled to fit some conception of an ideally fair distribution of resources. Whether any kind of social democracy can be reconciled with the anarchic energies of global markets is an open question.

Keynes had a political objective. Unless governments took steps to stabilize market economies at full employment, much of the undoubted benefit of markets would be lost and political space would be opened up for extremists who would offer to solve the economic problem by abolishing markets, peace and liberty. This in a nutshell was the Keynesian 'political economy'. Keynes offers an immensely fruitful way of making sense of the slump now in progress, for suggesting policies to get us out of the slump, for ensuring, as far as is humanly possible, that we don't continue to fall into pits like the present one, and for understanding the human condition. These are the things which make Keynes fresh today.

Keynesian economics was, in the context of those times, essentially conservative. The message was that capitalism was not doomed; its major failing, chronic large-scale unemployment, could be remedied fairly easily, by intelligent use of the fiscal and monetary instruments governments already had at their disposal. This message was not welcome news to Marxists committed to the view that the system was no longer structurally capable of prosperity and progress.

But while Keynes as well as the subsequent research in new Keynesian economics has provided an explanation for both unemployment and economic volatility while it has attempted to identify precisely what is wrong with the Arrow-Debreu model that can account for these observations there was another message of Keynes that was clearly heard: The macroeconomic ills of capitalism were curable. One didn't need to institute fundamental reforms in the economic system. One only needed selective government intervention. It is in this sense that Keynesian economics greatly weakened the case for market socialism.

Keynesian economics at a minimum provides a license for welfare state measures and other government efforts towards redistribution of wealth. The license is the faith that macroeconomic stabilization and prosperity are compatible with a wide range of social policies, that modern capitalism and democracy are robust enough to prosper and progress while being humane and equitable. That faith conflicts with the visions of extreme Right and Left, which agree that extremes of wealth and poverty, of security and insecurity, are indispensable to the functioning of capitalism. Keynesian policies helped to confound those dismal prophecies in the past; I think they will do so again.

Broadly speaking, [Keynesianism means] that the government has a specific responsibility for the behavior of the economy, that it doesn't work on its own autonomous course, but the government, when there's a recession, compensates by employment, by expansion of purchasing power, and in boom times corrects by being a restraining force. But it controls the great flow of demand into the economy, what since Keynesian times has been the flow of aggregate demand. That was the basic idea of Keynes so far as one can put it in a couple of sentences.

I mean, it became particularly acute because Keynes, against his intentions, had stimulated the development of macroeconomics. And I was convinced that not only his particular conclusions, but the whole foundation of macroeconomics was wrong.
So I wanted to demonstrate that we had to return to microeconomics, that this whole prejudice supported by the natural scientists that could deduce anything from measurable magnitudes, the effects of aggregates and averages, came to fascinate me much more. I felt in a way, that the thing which I am now prepared to do, I don’t know as there’s anybody else who can do this particular task. And I rather hoped that what I had done in capital theory would be continued by others. This was a new opening which was much more fascinating. The other would have meant working for a result which I already knew, but had to prove it. Which was very dull.
The other thing was an open problem: How does economics really look like when you recognize it as the prototype of a new kind of science of complex phenomena which could not employ the simple model of mechanics or physics, but had to deal with what then I described as mere pattern predictions, certain limited prediction. That was so much more fascinating as an intellectual problem.

The legacy of Keynesian economics — the misdiagnosis of unemployment, the fear of saving, and the unjustified faith in government intervention — affected the fundamental ideas of policy makers for a generation and altered such basic institutions of our economy as the tax laws, the social insurance programs and the financial system. Changing these deeply ingrained aspects of economic life can happen only slowly. But the economics profession has undoubtedly begun to re-examine and re-evaluate the Keynesian notions that have been so dominant for the past 35 years. There is a return to older and more basic economic truths and an attempt to adapt these ideas to the changing conditions of technology and affluence. From this is emerging a new view of unemployment, of saving, and of the role of government.

John Maynard Keynes saw the truth at the bottom of all this, which is that our fixation on what he called "purposiveness" — on using time well for future purposes, or on "personal productivity," he might have said, had he been writing today — is ultimately motivated by the desire not to die. "The 'purposive' man," Keynes wrote, "is always trying to secure a spurious and delusive immortality for his actions by pushing his interests in them forward into time. He does not love his cat, but his cat's kittens; nor in truth the kittens, but only the kittens' kittens, and so on forward forever to the end of cat-dom.

The question remains: to what extent were the successes and failures of the golden age the result of Keynesian theory, however bastardized? The quick answer is: to a much greater extent in the former than in the latter. Keynesianism provided an analytical framework for organizing policy choices. It also provided ad hoc rationalizations for what governments wanted to do for other reasons. At the rhetorical level, these were important. They created the expectation that full employment would be maintained by policy. This reinforced the favourable background for business investment. To a more limited extent, Keynesian policy as practised in the 1 9 6os brought the golden age into crisis: but there were more profound reasons relating to the drift of social policy (sometimes called the 'revolution in entitlements'), the role of the United States in the world, and the weakness of the Bretton Woods system of international institutions. So the old coach did make a difference.

Keynes tried to show that market economies could settle in equilibrium states in which the labour market did not clear, and in which the level of unemployment was high. He believed that this was due to a particular example of market failure, developed in his concept of effective demand.