A Falling Out
It is one thing to make promises that fail to come true. It is far worse to make promises in which the opposite occurs. Supply-side economics, monetarism, and free floating had the unfortunate fate of promising the opposite of what actually happened. In every case, there was little doubt that the experimenters failed to deliver on their key promises. A scientific theory, suffering a comparable failure, would not have much of a future. Economic theories, however, have much more resilience.
The results of a laboratory experiment can be just as important when they confirm a hypothesis as when they refute it. In either case something is learned. The same principle does not necessarily apply to macroeconomic experiments. In these experiments there are no laboratory controls to eliminate extraneous factors. Results can always be contaminated, which raises the question of how important these other things are. The failures of these experiments ignited a desperate search for confounding factors. The failure of the three experiments to fulfill their promises led to a variety of explanations and excuses. At stake was the reputtion of more than a few professional economists.