P6: Historical context for Keynes
from Asad Zaman
This post, 6th in a sequence about Re-Reading Keynes, continues to borrow heavily from Brian S. Ferguson, “Lectures on John Maynard Keynes’ General Theory of Employment, Interest and Money (1): Chapter One, Background and Historical Setting” University of Guelph Department of Economics and Finance Discussion Paper No. 2013-06. However the first three paragraphs are mine.
Distinguishing between ideologies and science:
Deduction: According to Lionel Robbins, economic theory uses an axiomatic deductive methodology, based on logical deduction from postulates which are “simple and indisputable facts of experience.” This means that there is no possibility of mistakes, and hence no possibility of learning from empirical evidence. If someone claims to have drawn a triangle where three angles do not sum to 180, we would not examine this triangle carefully to see if our law is empirically refuted. This is exactly the defining feature of an ideology – it does not waver in face of empirical evidence to the contrary. For more details, see Economic Theory as Ideology. This is important because today we are still fighting the same battles, discussing the same questions, which were being discussed at the time of Keynes. Macroecconomics has been going backwards for decades, and there has been failure to learn from experience, due to the adoption of axiomatic-deductive methodology by economists.
Induction: As opposed to this, scientific laws derived from induction are always falsifiable – the next experience may refute them. As a result, revisions are frequently necessary, as more and more experience comes in. The central insight of Kuhn is that scientific progress occurs via revolutions, which destroy one established way of looking at the world, and replace it with another. One of the key assertions of Polanyi is that when social change occurs, people devise theories to try to understand the new phenomena. These theories are often wrong, because lack of experience leads to misunderstandings. The ability to arrive at good theories depends crucially on the ability to revise theories in light of experience. read more