Ludwig von Mises and Friedrich Hayek, the most prominent “Austrian” economists of the time, anticipated the 1929 stock market crash and correctly predicted the dire consequences of government attempts to artificially stimulate economic growth in the aftermath of the crash. John Maynard Keynes, on the other hand, was totally blindsided by the stock market crash and the economic disaster of the early 1930s. And yet, Keynes’s theories gained enormous popularity during the 1930s whereas the work of Mises and Hayek was largely ignored. Why was it so?

Keynes became popular because he told the politically powerful what they wanted to hear. In particular, he provided power-hungry politicians with intellectual support for the schemes they not only already had in mind, but in many cases were already putting into practice. Despite being riddled with errors, Keynes’ theories also appealed to many economists because the implementation of these theories would confer a lot more influence upon the economics fraternity. The fact is that in a free economy there wouldn’t be much for an economist to do other than teach economics. He/she would certainly never have the opportunity to be involved in the ‘management’ of the economy.

The points outlined in the above paragraph, along with Keynes’ charisma and salesmanship, explain why “Keynesian” economic theories became dominant, but it doesn’t explain how they managed to stay dominant in the face of an ever-growing mountain of evidence indicating that they result in long-term economic decline.

As far as I can tell, the theories have stayed popular for three main reasons. First, not only do they mesh with the personal goals of almost all current politicians, but also there is now a huge government apparatus in place that depends upon the continued application of these theories. In other words, a large chunk of the population now has a vested interest in perpetuating the myth that the government should ‘manage’ the economy. Second, it usually isn’t possible to disprove an economic theory using data, because the same data can usually be interpreted in different ways and used to justify opposing theories. The hard reality is that in the science of economics you must start with the correct theory in order to correctly interpret the data. Third, Keynesianism is more like a stream of anecdotes than a coherent theory, in that under this so-called theory most things are ‘explained’ by unforeseeable events and unpredictable shifts in “animal spirits”. It is impossible to invalidate an intellectual position that is constantly changing.

A good example of how the same data can be interpreted in different ways in order to support conflicting theories is provided by the 1937-1939 collapse of the US economy. According to the “Austrians”, the fact that the US federal government propped up prices, drastically increased its spending, inflated the money supply, began interfering with many industries and generally did whatever it could to prevent the corrective process from running its course following the 1929 stock market crash guaranteed that all signs of economic recovery would quickly disappear as soon as the artificial support was scaled back. The mistake, according to the “Austrians”, was to provide the artificial support. According to the “Keynesians”, however, the mistake was to remove the artificial support prematurely. They argue that the government and the Fed should have continued to do whatever was needed to postpone a collapse, the idea being that with enough government assistance in the form of new money, new regulations, handouts, price controls and job-creating public works projects the economy would eventually gain enough strength to become self-supporting.

Unfortunately, when throwing ‘Keynesian stimulus’ in the form of more government spending, more credit and more monetary inflation at an economic downturn doesn’t lead to a self-sustaining recovery, the followers of Keynes will always have two comebacks. They can always assert that the stimulus would have worked if only it had been done more aggressively and/or that as bad as the economy has performed it would have performed even worse if not for the stimulus.

You can’t argue with that. At least, it’s an assertion that can never be unequivocally invalidated because it is never possible to go back in time and show what would have happened with different policies.