Robert Shiller explains:
Adherents to Keynes’s message were so eager to get this simple policy implemented, on both sides of the Atlantic, that they failed to notice – or perhaps they intentionally disregarded – that the General Theory also had a deeper, more fundamental message about how capitalism worked, if only briefly spelled out. It explained why capitalist economies, left to their own devices, without the balancing of governments, were essentially unstable. And it explained why, for capitalist economies to work well, the government should serve as a counterbalance.
The key to this insight was the role Keynes gave to people’s psychological motivations. These are usually ignored by macroeconomists. Keynes called them animal spirits, and he thought they were especially important in determining people’s willingness to take risks. Businessmen’s calculations, he said, were precarious: “Our basis of knowledge for estimating the yield 10 years hence of a railway, a copper mine, a textile factory, the goodwill of a patent medicine, an Atlantic liner, a building in the City of London amounts to little and sometimes to nothing.” Despite this, people somehow make decisions and act. This “can only be taken as a result of animal spirits”. There is “a spontaneous urge to action”.
To a remarkable extent we have got into the current economic and financial crisis because of a wrong economic theory – an economic theory that itself denied the role of the animal spirits in getting us into manias and panics.
It is the role of the government at two levels to see that these events do not occur. First, it has a duty to regulate asset markets so that people are not falsely lured into buying snake-oil assets. Such standards for our financial assets make as much common sense as the standards for the food we eat, or the purchase medicine we get from the pharmacy. But we do not want to throw out the good parts of capitalism with the bad. To take advantage of the good parts of capitalism, when fluctuations occur it is the role of the government to see that those who can and want to produce what others want to buy can do so. It is the role of the government, through its counterbalancing fiscal and monetary policy, to maintain full employment.
The principles behind such an economy are not the principles behind a socialist economy. The government insofar as possible is only creating the macroeconomic conditions that will allow the economy to function well.
That is the role of government. Its role is to ensure a “wise laisser faire”. This is not the free-for-all capitalism that has been recommended by the current economic theory, and seems to have been accepted as gospel by economic planners, and also many economists, since the Thatcher and Reagan governments. But it also is a significant middle way between those who see the economic disasters and unemployment of unfettered capitalism, on the one hand, and those who believe that the government should play no role at all.
The idea that unfettered, unregulated capitalism would invariably produce the good outcomes was a wrong economic theory regarding how capitalist societies behave and what causes their crises. That wrong economic theory fails to take account of how the animal spirits affect economic behaviour. It fails to take into account the roles of confidence, stories and snake oil in economic fluctuation.
Also see this opinion piece by Martin Wolf