For the last 50 years or so, economists have taken very seriously their subject's appellation of "social science." They have resolutely copied the methodology of the physical sciences, which emphasizes exact measurement and the establishment of precise and consistent relationships.
By employing that methodology, physical scientists have acquired an enormous mass of reliable knowledge about the world's physical properties; the application of that knowledge has enabled the world to achieve its present level of material well-being.
Economists aspire to similar achievement. They hope to amass a body of rigorously ascertained relationships that would explain economic phenomena; such knowledge would be solid and sure, free of the vagueness, uncertainty and subjectivity that characterized the speculations and introspections which constituted economics in the past.
Hence for years now academic economists, in analyzing economic problems, have directed their attention almost exclusively at those elements which could be precisely described and measured. Explanation has typically been in the form of mathematical equations which rigorously express relationships between exactly measured elements.
All economic affairs involve human beings. Economic events occur the way they do because people act the way they do. And when some new economic development occurs it is usually because of the people involved, because they have significantly changed their attitudes, capacities or desires.
Human attitudes, capacities and desires cannot easily be measured - certainly not with the reliability and precision required by scientists. In analyzing economic problems scholars have therefore resolutely ignored the human element. The unmeasurable is the unmentionable.
Learned articles on inflation, for instance, searchingly examine relationships of national income, spending on consumption, investment, government spending, the budget deficit, the balance of payments deficit, saving, the money supply, the interest rate. No attempt is made to ascertain what changes may have occurred in the human beings involved and how these may be contributing to inflation for example.