Deductivism — the original sin of ‘modern’ economics30 September, 2015 at 12:57 | Posted in Economics | 3 Comments
For many people, deductive reasoning is the mark of science: induction – in which the argument is derived from the subject matter – is the characteristic method of history or literary criticism. But this is an artificial, exaggerated distinction. Scientific progress … is frequently the result of observation that something does work, which runs far ahead of any understanding of why it works.
Not within the economics profession. There, deductive reasoning based on logical inference from a specific set of a priori deductions is “exactly the right way to do things”. What is absurd is not the use of the deductive method but the claim to exclusivity made for it. This debate is not simply about mathematics versus poetry. Deductive reasoning necessarily draws on mathematics and formal logic: inductive reasoning, based on experience and above all careful observation, will often make use of statistics and mathematics …
The belief that models are not just useful tools but are capable of yielding comprehensive and universal descriptions of the world blinded proponents to realities that had been staring them in the face. That blindness made a big contribution to our present crisis, and conditions our confused responses to it.
Kay’s article is essential reading for all those who want to understand why mainstream – neoclassical – economics actively have contributed to causing todays’s economic crisis rather than to solving it.
Perhaps this becomes less perplexing to grasp when considering what one of its main proponents today – Robert Lucas – maintained already in 2003:
My thesis in this lecture is that macroeconomics in this original sense has succeeded: its central problem of depression-prevention has been solved, for all practical purposes, and has in fact been solved for many decades.
And this comes from an economist who has built his whole career on the assumption that people are hyper rational “robot imitations” with rational expectations and (stochastically) perfect ability to process information. Mirabile dictu!