This article is reprinted from the October 1993 Freeman.

The economics of John Maynard Keynes as taught to university sophomores for the last several decades is now nearly defunct in theory but not in practice. Keynes’s 1936 book, The General Theory of Employment, Interest, and Money, portrayed the market as fundamentally unstable and touted government as the stabilizer. The stability that allegedly lay beyond the market’s reach was to be supplied by the federal government’s macroeconomic policymakers—the president (with guidance from his Council of Economic Advisers), the Congress, and the Federal Reserve.

The acceptance in the economics profession of fundamentalist Keynesianism peaked in the 1960s. In recent decades, enthusiasm for Keynes has waxed and waned as proponents have tried to get new ideas from the General Theory or to read their own ideas into it. And although the federal government has long since become a net supplier of macroeconomic instability, the institutions and policy tools that were fashioned to conform to the Keynesian vision have become an integral part of our economic and political environment.

A national income accounting system, devised with an eye to Keynesian theory, allowed statisticians to chart the changes in the macroeconomy. Dealing in terms of an economy-wide total, or aggregate, policy advisers tracked the production of goods and services bought by consumers, investors, and the government. Fiscal and monetary authorities were to spring into action whenever the economy’s actual, or measured, total output, which was taken to reflect the demand side of markets, fell short of its potential output, which was estimated on the basis of the supply side. Cutting taxes would allow consumers and investors to spend more; government spending would add directly to the total; printing money or borrowing it would facilitate the opposing movements in the government’s revenues and its expenditures.

A chronic insufficiency of aggregate demand, which implies that prices and wages are somehow stuck above their market-clearing levels, was believed to be the normal state of affairs. Why might there be such pricing problems on an economy-wide scale? What legislation and government institutions might be standing in the way of needed market adjustments? These questions were eclipsed by the more politically pressing question of how to augment demand so as to clear markets at existing prices. The New Economics of Keynes shifted the focus of attention from the market to the government, from economically justified changes in market pricing to politically justified changes in government spending.

Politicians still appeal to basic Keynesian notions to justify their interventionist schemes. The continued use of demand-management policies aimed at stimulating economic activity—spending newly printed or borrowed money during recessions and before elections—requires that we understand what Keynesian economics is all about and how it is flawed. Also, identifying the flaws at the sophomore level helps students to evaluate in their upper-level and graduate courses such modern modifications as Post-, Neo-, and New Keynesianism as well as some strands of Monetarism.

The extreme level of aggregation in Keynesian economics leaves the full range of choices and actions of individual buyers and sellers hopelessly obscured. Keynesian economics simply does not deal with supply and demand in the conventional sense of those terms. Instead, the entire private sector is analyzed in terms of only two categories of goods: consumption goods and investment goods. The patterns of prices within these two mammoth categories are simply dropped out of the picture. To make matters worse, the one relative price that is retained in this formulation—the relative value of consumer goods to investment goods as expressed by the interest rate—is assumed either not to function at all or to function perversely.

Keynes’s Neglect of Scarcity

Pre-Keynesian economics, such as that of John Stuart Mill, as well as most contemporaneous theorizing, such as that by Ludwig von Mises and F. A. Hayek, emphasized the notion of scarcity, which implies a fundamental trade-off between producing consumption goods and producing investment goods. We can have more of one but only at the expense of the other. The construction of additional plant and equipment must be facilitated by increased savings—that is, by a decrease in current consumption. Such investment, of course, makes it possible for future consumption to increase. Identifying the market mechanisms that allocate resources over time is fundamental to our understanding of the market process in its capacity to tailor production decisions to consumption preferences. But as Hayek noted early on, the Keynesian aggregates serve to conceal these very mechanisms so essential to the intertemporal allocation of resources and hence to macroeconomic stability.

In Keynesian theory the long-established notion of a trade-off between consuming and investing is simply swept aside. Consistent with the assumed perversity of the price mechanism, the levels of consumption and investment activities are believed always to move in the same direction. More investment generates more income, which finances more consumption; more consumption stimulates more investment. This feature of Keynesian theory implies an inherent instability in market economies. Thus the theory cannot possibly explain how a healthy market economy functions—how the market process allows one kind of activity to be traded off against the other.

The “Multiplier-Accelerator” Theory

The inherent instability makes its textbook appearance as the interaction between the “multiplier,” through which investment affects consumption, and the “accelerator,” through which consumption affects investment. The multiplier effect is derived from the simple fact that one person’s spending becomes another person’s earnings, which, in turn, allows for further spending. Any increase in spending, then, whether originating from the private or public sector, gets multiplied through successive rounds of income earning and consumption spending.

The accelerator mechanism is a consequence of the durability of capital goods, such as plant and equipment. For instance, a stock of ten machines, each of which lasts ten years, can be maintained by purchasing one new machine each year. A slight but permanent increase in consumer demand for the output of the machines of, say, 10 percent, will justify maintaining a capital stock of eleven machines. The immediate result, then, will be an acceleration of current demand for new machines from one to two, an increase of 100 percent.

The multiplier-accelerator theory explains why consumption is increasing, given that investment is increasing, and why investment is increasing, given that consumption is increasing. But it is incapable of explaining what determines the actual levels of consumption and investment (except in terms of one another), why either should be increasing or decreasing, or how both can increase at the same time. Students are left with the general notion that the two magnitudes, investment and consumption, can feed on one another, in which case the economy is experiencing an economic expansion, or they can starve one another, in which case the economy is experiencing an economic contraction. That is, Keynesian theory explains how the multiplier-accelerator mechanism makes a good situation better or a bad situation worse, but it never explains why the situation should be good or bad in the first place.

Only at the two extremities in the level of economic activity is a change in direction of both consumption and investment sure to occur. After a long contraction, unemployment is pervasive and capital depreciation reaches critical levels. As production essential for capital replacement stimulates further economic activity, the macroeconomy begins to spiral upward. After a long expansion, the economy is bulging at the seams. Markets are glutted with both consumers’ and producers’ goods. As unsold inventories trigger production cutbacks and worker layoffs, the macroeconomy begins to spiral downward. Keynes held that the economy normally fluctuates well within these two extremes experiencing a general insufficiency—and an occasional supersufficiency—of aggregate demand.

Textbook Keynesianism

In the simplistic formulations of macroeconomic textbooks, investment is simply “given”; in Keynes’s own formulation, the inclination of the business community to invest is governed by psychological factors as summarized by the colorful term “animal spirits.” Keynes recognized that there are some “external factors” at work, such as foreign affairs, population growth, and technological discoveries. The market is envisioned, in effect, to be some sort of economic amplifier which converts relatively small changes in these external factors into wide swings of employment and output. This is the basic Keynesian vision.

Wage rates and prices are assumed either to be inflexible or to change in direct proportion to one another. In either case the real wage (W/P) is forever constant. The actual level of wages and prices is believed to be determined (again) by external factors—this time, trade unions and large corporations. If the real wage is too high, there will be unemployment on an economy-wide basis. There will be idle labor and idle resources of every kind. The opportunity cost of putting these resources back to work is nothing but forgone idleness, which is no cost at all. The assumed normalcy of massive resource idleness assures that the perennial problem of scarcity never comes into play. William H. Hutt and F. A. Hayek were justified in referring to Keynesian economics as the “theory of idle resources” and the “economics of abundance.”

Textbook Keynesianism has a certain internal consistency or mathematical integrity about it. Given the assumptions that prices and wages do not properly adjust to market conditions—that is, the assumption that the price system does not work—then the Keynesian relationships among the macroeconomic aggregates come into play. Even the policy prescriptions seem to follow: If wages and prices do not adjust to the existing market conditions, then market conditions must be adjusted (by the fiscal and monetary authorities) to the externally determined prices and wages.

In the final analysis, however, Keynesian theory is a set of mutually reinforcing but jointly unsupportable propositions about how certain macroeconomic aggregates are related to one another. Keynesian policy is a set of self-justifying policy prescriptions. For instance, if the government is convinced that wages will not fall and is prepared to hire the unemployed, then unemployed workers will not be willing to accept a lower market wage, ensuring that wages, in fact, will not fall. Thus, while the intention of Keynesian policy is to stabilize the economy, the actual effect is to “Keynesianize” the economy. It causes the economy to behave in exactly the same perverse manner that is implied by the Keynesian assumptions. This convoluted interrelationship between theory and policy has long obscured the fundamental flaws in the theory itself.

Students often ask the obvious question: Why is government policy grounded in such a flawed theory? From a political point of view, advocating and implementing Keynesian policy is the surest way to election and reelection. The gains from printing and spending money are immediate, highly visible, and can be concentrated on individuals who make up powerful voting blocs. The costs of this policy are incurred at a later date and can be spread thinly across the entire population, making the link between policy and long-run consequences difficult for the voting public to perceive.

The fading in recent years of old-line Keynesianism in academic circles provides little comfort. Even as the number of demand-managers continues to decline, it is from this shrinking group of economists that government officials seek advice and reconciliation. And opportunities to lecture to the seats of power rather than in the halls of learning have a way of changing some economists’ minds about the advisability (political if not economic) of managing aggregate demand. Printing and spending money in pursuit of short-run stimulation if not long-run stability remain the order of the day.

There is good reason, then, to study Keynesian theory: It helps us understand what the policymakers in government are likely to do in any given circumstance. But to understand the actual effects of their demand-management policies in the long run as well as the short, we need a more enlightening theory—one that recognizes what market forces can do on their own to maintain macroeconomic stability and how those forces are foiled by government-supplied stabilization.