“We cannot, as economic scientists, say that any policy will increase total social utility. There is no way to measure “total social utility.” So effective is this argument that it denies to economics the legitimacy of making estimates of the total value of any aggregates. What does Gross National Product mean, anyway, if we cannot assign any value (or meaning) to the columns of figures in a GNP index? If Robbins’ thesis is correct—and since 1932, no economist has shown how it might be incorrect—then most of what we know as modern applied economics, including the formulation of economic policy, is an illusion.” Gary North
Say’s Law or Say’s Law of Markets is a principle attributed to French businessman and economist Jean-Baptiste Say, stating that there can be no demand without supply. He theorized that the activity of production opens a demand for the products produced. Thus the mere creation of one product immediately opens an avenue for other products. To put it another way, Say was making the claim that production is the source of demand. One’s ability to demand goods and services from others derives from the income produced by one’s own acts of production. Wealth is created by production not by consumption. My ability to demand food, clothing, and shelter derives from the productivity of my labor or my nonlabor assets. The higher or lower that productivity is, the higher or lower is my power to demand other goods and services.