Arnold Kling tackles the hardy perennial topic “How Effective is Economic Theory?” in the Summer 2017 issue of National Affairs. His overall approach is to focus on “five interlocking subjects in particular: mathematical modeling, homo economicus, objectivity, testing procedures, and the particular status of the sub-discipline of macroeconomics.” He then compares and contrasts what economists were saying about those subjects in 1966 and 1980, compared with his views on current patterns. For details, read the essay! But here are few excerpts that caught my eye and may give some flavor of his discussion:
“Economists are not without knowledge. We know that restrictions on trade tend to help narrow interests at the expense of broader prosperity. We know that market prices are important for coordinating specialization and division of labor in a complex economy. We know that the profit incentive promotes the introduction of improved products and processes, and that our high level of well-being results from the cumulative effect of such improvements. We know that government control over prices and production, as in communist countries, leads to inefficiency and corruption. We know that the laws of supply and demand tend to frustrate efforts to make goods more “affordable” by subsidizing them or to lower “costs” by fixing prices.
“But policymakers have goals that go far beyond or run counter to such basic principles. They want to steer the economy using fiscal stimulus. They want to shape complex and important markets, including those of health insurance and home mortgages. It is doubtful that the effectiveness of economic theory is equal to such tasks.
“Most scholarly research in economics is ultimately motivated by the unrealistic goal of providing effective theory to implement such technocratic objectives. But the resulting economic theory cannot be applied with the same confidence as Newtonian physics. Even worse is the fact that economists, unlike physicists, are not clear about the limits of the effectiveness of their theories. In short, when it comes to effective theory, economists promise more than they can deliver. …”