Rational Expectations
by Thomas J. Sargent
The theory of rational expectations was first proposed by John F. Muth of Indiana University in the early sixties. He used the term to describe the many economic situations in which the outcome depends partly upon what people expect to happen. The price of an agricultural commodity, for example, depends on how many acres farmers plant, which in turn depends on the price that farmers expect to realize when they harvest and sell their crops. As another example, the value of a currency and its rate of depreciation depend partly on what people expect that rate of depreciation to be. That is because people rush to desert a currency that they expect to lose value, thereby contributing to its loss in value. Similarly, the price of a stock or bond depends partly on what prospective buyers and sellers believe it will be in the future.
The use of expectations in economic theory is not new. Many earlier economists, including A. C. Pigou, John Maynard Keynes, and John R. Hicks, assigned a central role in the determination of the business cycle to people's expectations about the future. Keynes referred to this as "waves of optimism and pessimism" that helped determine the level of economic activity. But proponents of the rational expectations theory are more thorough in their analysis of—and assign a more important role to—expectations.
The influences between expectations and outcomes flow both ways. In forming their expectations, people try to forecast what will actually occur. They have strong incentives to use forecasting rules that work well because higher "profits" accrue to someone who acts on the basis of better forecasts, whether that someone be a trader in the stock market or someone considering the purchase of a new car. And when people have to forecast a particular price over and over again, they tend to adjust their forecasting rules to eliminate avoidable errors. Thus, there is continual feedback from past outcomes to current expectations. Translation: in recurrent situations the way the future unfolds from the past tends to be stable, and people adjust their forecasts to conform to this stable pattern.
The concept of rational expectations asserts that outcomes do not differ systematically (i.e., regularly or predictably) from what people expected them to be. The concept is motivated by the same thinking that led Abraham Lincoln to assert, "You can fool some of the people all of the time, and all of the people some of the time, but you cannot fool all of the people all of the time." From the viewpoint of the rational expectations doctrine, Lincoln's statement gets things right. It does not deny that people often make forecasting errors, but it does suggest that errors will not persistently occur on one side or the other.
Economists who believe in rational expectations base their belief on the standard economic assumption that people behave in ways that maximize their utility (their enjoyment of life) or profits. Economists have used the concept of rational expectations to understand a variety of situations in which speculation about the future is a crucial factor in determining current action. Rational expectations is a building block for the "random walk" or "efficient markets" theory of securities prices, the theory of the dynamics of hyperinflations, the "permanent income" and "life-cycle" theories of consumption, the theory of "tax smoothing," and the design of economic stabilization policies.
The Efficient Markets Theory of Stock Prices
One of the earliest and most striking applications of the concept of rational expectations is the efficient markets theory of asset prices. A sequence of observations on a variable (such as daily stock prices) is said to follow a random walk if the current value gives the best possible prediction of future values. The efficient markets theory of stock prices uses the concept of rational expectations to reach the conclusion that, when properly adjusted for discounting and dividends, stock prices follow a random walk. The chain of reasoning goes as follows. In their efforts to forecast prices, investors comb all sources of information, including patterns that they can spot in past price movements.
Investors buy stocks that they expect to have a higher-than-average return and sell those that they expect to have lower returns. When they do so, they bid up the prices of stocks expected to have higher-than-average returns and drive down the prices of those expected to have lower-than-average returns. The prices of the stocks adjust until the expected returns, adjusted for risk, are equal for all stocks. Equalization of expected returns means that investors' forecasts become built into or reflected in the prices of stocks. More precisely, it means that stock prices change so that after an adjustment to reflect dividends, the time value of money, and differential risk, they equal the market's best forecast of the future price. Therefore, the only factors that can change stock prices are random factors that could not be known in advance. Thus, changes in stock prices follow a random walk.
The random walk theory has been subjected to literally hundreds of empirical tests. The tests tend to support the theory quite strongly. While some studies have found situations that contradict the theory, the theory does explain, at least to a very good first approximation, how asset prices evolve (see Efficient Capital Markets).
The Permanent Income Theory of Consumption
The Keynesian consumption function holds that there is a positive relationship between people's consumption and their income. Early empirical work in the forties and fifties encountered some discrepancies from the theory, which Milton Friedman successfully explained with his celebrated "permanent income theory" of consumption. Friedman built upon Irving Fisher's insight that a person's consumption ought not to depend on current income alone, but also on prospects of income in the future. Friedman posited that people consume out of their "permanent income," which can be defined as the level of consumption that can be sustained while leaving wealth intact. In defining "wealth," Friedman included a measure of "human wealth"—namely, the present value of people's expectations of future labor income.
Although Friedman did not formally apply the concept of rational expectations in his work, it is implicit in much of his discussion. Because of its heavy emphasis on the role of expectations about future income, his hypothesis was a prime candidate for the application of rational expectations. In work subsequent to Friedman's, John F. Muth and Stanford's Robert E. Hall imposed rational expectations on versions of Friedman's model, with interesting results. In Hall's version, imposing rational expectations produces the result that consumption is a random walk: the best prediction of future consumption is the present level of consumption. This result encapsulates the consumption-smoothing aspect of the permanent income model and reflects people's efforts to estimate their wealth and to allocate it over time. If consumption in each period is held at a level that is expected to leave wealth unchanged, it follows that wealth and consumption will each equal their values in the previous period plus an unforecastable or unforeseeable random shock—really a forecast error.
The rational expectations version of the permanent income hypothesis has changed the way economists think about short-term stabilization policies (such as temporary tax cuts) designed to stimulate the economy. Keynesian economists used to believe that tax cuts would boost disposable income and thus cause people to consume more. But according to the permanent income model, temporary tax cuts would have much less of an effect on consumption than Keynesians had thought. The reason is that people are basing their consumption decision on their wealth, not their current disposable income. Because temporary tax cuts are bound to be reversed, they have little or no effect on wealth, and therefore, they have little or no effect on consumption. Thus, the permanent income model had the effect of diminishing the expenditure "multiplier" that economists ascribed to temporary tax cuts.
The rational expectations version of the permanent income model had been extensively tested, with results that are quite encouraging. The evidence is that the model works well but imperfectly. Economists are currently extending the model to take into account factors such as "habit persistence" in consumption and the differing durabilities of various consumption goods. Expanding the theory to incorporate these features alters the pure "random walk" prediction of the theory (and so helps remedy some of the empirical shortcomings of the model), but it leaves the basic permanent income insight intact.
Tax-Smoothing Models
How should a government design tax policy when it knows that people are making decisions partly in response to the government's plans for setting taxes in the future? That is, when participants in the private sector have rational expectations about the government's rules for setting tax rates, what rules should the government use to set tax rates? Robert Lucas and Nancy Stokey, as well as Robert Barro, have studied this problem under the assumption that the government can make and keep commitments to execute the plans that it designs. All three authors have identified situations in which the government should finance a volatile (or unsmooth) sequence of government expenditures with a sequence of tax rates that is quite stable (or smooth) over time. Such policies are called "tax-smoothing" policies. Tax smoothing is a good idea because it minimizes the supply disincentives associated with taxes. For example, workers who pay a 20 percent marginal tax rate every year will reduce their labor supply less (that is, will work more at any given wage) than they would if the government set a 10 percent marginal tax rate in half the years and a 30 percent rate in the other half.
During "normal times" a government operating under a tax-smoothing rule typically has close to a balanced budget. But during times of extraordinary expenditures—during wars, for example—the government runs a deficit, which it finances by borrowing. During and after the war the government increases taxes by enough to service the debt it has occurred; in this way the higher taxes that the government imposes to finance the war are spread out over time. Such a policy minimizes the cumulative distorting effects of taxes—the adverse "supply-side" effects.
Barro's tax-smoothing theory helps explain the behavior of the British and U.S. governments in the eighteenth and nineteenth centuries, when the standard pattern was to finance wars with deficits but to set taxes after wars at rates sufficiently high to service the government's debt.
Expectational Error Models of the Business Cycle
A long tradition in business cycle theory has held that errors in people's forecasts are a major cause of business fluctuations. This view was embodied in the Phillips curve (the observed inverse correlation between unemployment and inflation), with economists attributing the correlation to errors that people made in their forecasts of the price level. Before the advent of rational expectations, economists often proposed to "exploit" or "manipulate" the public's forecasting errors in ways designed to generate better performance of the economy over the business cycle. Thus, Robert Hall aptly described the state of economic thinking in 1973 when he wrote:
The benefits of inflation derive from the use of expansionary policy to trick economic agents into behaving in socially preferable ways even though their behavior is not in their own interest.... The gap between actual and expected inflation measures the extent of the trickery.... The optimal policy is not nearly as expansionary [inflationary] when expectations adjust rapidly, and most of the effect of an inflationary policy is dissipated in costly anticipated inflation.
Rational expectations undermines the idea that policymakers can manipulate the economy by systematically making the public have false expectations. Robert Lucas showed that if expectations are rational, it simply is not possible for the government to manipulate those forecast errors in a predictable and reliable way for the very reason that the errors made by a rational forecaster are inherently unpredictable. Lucas's work led to what has sometimes been called the "policy ineffectiveness proposition." If people have rational expectations, policies that try to manipulate the economy by inducing people into having false expectations may introduce more "noise" into the economy but cannot, on average, improve the economy's performance.
Design of Macroeconomic Policies
The "policy ineffectiveness" result pertains only to those economic policies that have their effects solely by inducing forecast errors. Many government policies work by affecting "margins" or incentives, and the concept of rational expectations delivers no "policy ineffectiveness" result for such policies. In fact, the idea of rational expectations is now being used extensively in such contexts to study the design of monetary, fiscal, and regulatory policies to promote good economic performance.
For example, extensions of the tax-smoothing models are being developed in a variety of directions. The tax-smoothing result depends on various special assumptions about the physical technology for transferring resources over time, and also on the sequence of government expenditures assumed. These assumptions are being relaxed, with interesting modifications of the tax-smoothing prescription being a consequence. Christophe Chamley reached the striking conclusion that an optimal tax scheme involves eventually setting the tax rate on capital to zero, with labor bearing the entire tax burden. To get his result, Chamley assumed that "labor" and "capital" are very different factors, with the total availability of labor being beyond people's control while the supply of capital could be affected by investment and saving. When Chamley's assumptions are altered to acknowledge the "human capital" component of labor, which can be affected by people's decisions, his conclusion about capital taxation is different.
The idea of rational expectations has also been a workhorse in developing prescriptions for optimally choosing monetary policy. Important contributors to this literature have been Truman Bewley and William A. Brock. Bewley and Brock's work describes precisely the contexts in which an optimal monetary arrangement involves having the government pay interest on reserves at the market rate. Their work supports, clarifies, and extends proposals to monetary reform made by Milton Friedman in 1960 and 1968.
Rational expectations has been a working assumption in recent studies that try to explain how monetary and fiscal authorities can retain (or lose) "good reputations" for their conduct of policy. This literature is beginning to help economists understand the multiplicity of government policy strategies followed, for example, in high-inflation and low-inflation countries. In particular, work on "reputational equilibria" in macroeconomics by Robert Barro and by David Gordon and Nancy Stokey has shown that the preferences of citizens and policymakers and the available production technologies and trading opportunities are not by themselves sufficient to determine whether a government will follow a low-inflation or a high-inflation policy mix.
Instead, reputation remains an independent factor even after rational expectations have been assumed.

posted by iambrianfu [ 11:21 AM ] <$BlogItemComments$>

New Keynesian Economics
by N. Gregory Mankiw
New Keynesian economics is the school of thought in modern macroeconomics that evolved from the ideas of John Maynard Keynes. Keynes wrote The General Theory of Employment, Interest, and Money in the thirties, and his influence among academics and policymakers increased through the sixties. In the seventies, however, new classical economists such as Robert Lucas, Thomas J. Sargent, and Robert Barro called into question many of the precepts of the Keynesian revolution. The label "new Keynesian" describes those economists who, in the eighties, responded to this new classical critique with adjustments to the original Keynesian tenets.
The primary disagreement between new classical and new Keynesian economists is over how quickly wages and prices adjust. New classical economists build their macroeconomic theories on the assumption that wages and prices are flexible. They believe that prices "clear" markets—balance supply and demand—by adjusting quickly. New Keynesian economists, however, believe that market-clearing models cannot explain short-run economic fluctuations, and so they advocate models with "sticky" wages and prices. New Keynesian theories rely on this stickiness of wages and prices to explain why involuntary unemployment exists and why monetary policy has such a strong influence on economic activity.
A long tradition in macroeconomics (including both Keynesian and monetarist perspectives) emphasizes that monetary policy affects employment and production in the short run because prices respond sluggishly to changes in the money supply. According to this view, if the money supply falls, people spend less money, and the demand for goods falls. Because prices and wages are inflexible and don't fall immediately, the decreased spending causes a drop in production and layoffs of workers. New classical economists criticized this tradition because it lacked a coherent theoretical explanation for the sluggish behavior of prices. Much new Keynesian research attempts to remedy this omission.
Menu Costs and Aggregate-Demand Externalities
One reason that prices do not adjust immediately to clear markets is that adjusting prices is costly. To change its prices, a firm may need to send out a new catalog to customers, distribute new price lists to its sales staff, or in the case of a restaurant, print new menus. These costs of price adjustment, called "menu costs," cause firms to adjust prices intermittently rather than continuously.
Economists disagree about whether menu costs can help explain short-run economic fluctuations. Skeptics point out that menu costs usually are very small. They argue that these small costs are unlikely to help explain recessions, which are very costly for society. Proponents reply that small does not mean inconsequential. Even though menu costs are small for the individual firm, they could have large effects on the economy as a whole.
Proponents of the menu-cost hypothesis describe the situation as follows. To understand why prices adjust slowly, one must acknowledge that changes in prices have externalities—that is, effects that go beyond the firm and its customers. For instance, a price reduction by one firm benefits other firms in the economy. When a firm lowers the price it charges, it lowers the average price level slightly and thereby raises real income. (Nominal income is determined by the money supply.) The stimulus from higher income, in turn, raises the demand for the products of all firms. This macroeconomic impact of one firm's price adjustment on the demand for all other firms' products is called an "aggregate-demand externality."
In the presence of this aggregate-demand externality, small menu costs can make prices sticky, and this stickiness can have a large cost to society. Suppose that General Motors announces its prices and then, after a fall in the money supply, must decide whether to cut prices. If it did so, car buyers would have a higher real income and would, therefore, buy more products from other companies as well. But the benefits to other companies are not what General Motors cares about. Therefore, General Motors would sometimes fail to pay the menu cost and cut its price, even though the price cut is socially desirable. This is an example in which sticky prices are undesirable for the economy as a whole, even though they may be optimal for those setting prices.
The Staggering of Prices
New Keynesian explanations of sticky prices often emphasize that not everyone in the economy sets prices at the same time. Instead, the adjustment of prices throughout the economy is staggered. Staggering complicates the setting of prices because firms care about their prices relative to those charged by other firms. Staggering can make the overall level of prices adjust slowly, even when individual prices change frequently.
Consider the following example. Suppose, first, that price setting is synchronized: every firm adjusts its price on the first of every month. If the money supply and aggregate demand rise on May 10, output will be higher from May 10 to June 1 because prices are fixed during this interval. But on June 1 all firms will raise their prices in response to the higher demand, ending the three-week boom.
Now suppose that price setting is staggered: Half the firms set prices on the first of each month and half on the fifteenth. If the money supply rises on May 10, then half the firms can raise their prices on May 15. Yet because half of the firms will not be changing their prices on the fifteenth, a price increase by any firm will raise that firm's relative price, which will cause it to lose customers. Therefore, these firms will probably not raise their prices very much. (In contrast, if all firms are synchronized, all firms can raise prices together, leaving relative prices unaffected.) If the May 15 price setters make little adjustment in their prices, then the other firms will make little adjustment when their turn comes on June 1, because they also want to avoid relative price changes. And so on. The price level rises slowly as the result of small price increases on the first and the fifteenth of each month. Hence, staggering makes the price level sluggish, because no firm wishes to be the first to post a substantial price increase.
Coordination Failure
Some new Keynesian economists suggest that recessions result from a failure of coordination. Coordination problems can arise in the setting of wages and prices because those who set them must anticipate the actions of other wage and price setters. Union leaders negotiating wages are concerned about the concessions other unions will win. Firms setting prices are mindful of the prices other firms will charge.
To see how a recession could arise as a failure of coordination, consider the following parable. The economy is made up of two firms. After a fall in the money supply, each firm must decide whether to cut its price. Each firm wants to maximize its profit, but its profit depends not only on its pricing decision but also on the decision made by the other firm.
If neither firm cuts its price, the amount of real money (the amount of money divided by the price level) is low, a recession ensues, and each firm makes a profit of only fifteen dollars.
If both firms cut their price, real money balances are high, a recession is avoided, and each firm makes a profit of thirty dollars. Although both firms prefer to avoid a recession, neither can do so by its own actions. If one firm cuts its price while the other does not, a recession follows. The firm making the price cut makes only five dollars, while the other firm makes fifteen dollars.
The essence of this parable is that each firm's decision influences the set of outcomes available to the other firm. When one firm cuts its price, it improves the opportunities available to the other firm, because the other firm can then avoid the recession by cutting its price. This positive impact of one firm's price cut on the other firm's profit opportunities might arise because of an aggregate-demand externality.
What outcome should one expect in this economy? On the one hand, if each firm expects the other to cut its price, both will cut prices, resulting in the preferred outcome in which each makes thirty dollars. On the other hand, if each firm expects the other to maintain its price, both will maintain their prices, resulting in the inferior solution, in which each makes fifteen dollars. Hence, either of these outcomes is possible: there are multiple equilibria.
The inferior outcome, in which each firm makes fifteen dollars, is an example of a coordination failure. If the two firms could coordinate, they would both cut their price and reach the preferred outcome. In the real world, unlike in this parable, coordination is often difficult because the number of firms setting prices is large. The moral of the story is that even though sticky prices are in no one's interest, prices can be sticky simply because people expect them to be.
Efficiency Wages
Another important part of new Keynesian economics has been the development of new theories of unemployment. Persistent unemployment is a puzzle for economic theory. Normally, economists presume that an excess supply of labor would exert a downward pressure on wages. A reduction in wages would, in turn, reduce unemployment by raising the quantity of labor demanded. Hence, according to standard economic theory unemployment is a self-correcting problem.
New Keynesian economists often turn to theories of what they call efficiency wages to explain why this market-clearing mechanism may fail. These theories hold that high wages make workers more productive. The influence of wages on worker efficiency may explain the failure of firms to cut wages despite an excess supply of labor. Even though a wage reduction would lower a firm's wage bill, it would also—if the theories are correct—cause worker productivity and the firm's profits to decline.
There are various theories about how wages affect worker productivity. One efficiency-wage theory holds that high wages reduce labor turnover. Workers quit jobs for many reasons—to accept better positions at other firms, to change careers, or to move to other parts of the country. The more a firm pays its workers, the greater their incentive to stay with the firm. By paying a high wage, a firm reduces the frequency of quits, thereby decreasing the time spent hiring and training new workers.
A second efficiency-wage theory holds that the average quality of a firm's work force depends on the wage it pays its employees. If a firm reduces wages, the best employees may take jobs elsewhere, leaving the firm with less productive employees who have fewer alternative opportunities. By paying a wage above the equilibrium level, the firm may avoid this adverse selection, improve the average quality of its work force, and thereby increase productivity.
A third efficiency-wage theory holds that a high wage improves worker effort. This theory posits that firms cannot perfectly monitor the work effort of their employees and that employees must themselves decide how hard to work. Workers can choose to work hard, or they can choose to shirk and risk getting caught and fired. The firm can raise worker effort by paying a high wage. The higher the wage, the greater is the cost to the worker of getting fired. By paying a higher wage, a firm induces more of its employees not to shirk and, thus, increases their productivity.
Policy Implications
Because new Keynesian economics is a school of thought regarding macroeconomic theory, its adherents do not necessarily share a single view about economic policy. At the broadest level new Keynesian economics suggests—in contrast to some new classical theories—that recessions do not represent the efficient functioning of markets. The elements of new Keynesian economics, such as menu costs, staggered prices, coordination failures, and efficiency wages, represent substantial departures from the assumptions of classical economics, which provides the intellectual basis for economists' usual justification of laissezfaire. In new Keynesian theories recessions are caused by some economy-wide market failure. Thus, new Keynesian economics provides a rationale for government intervention in the economy, such as countercyclical monetary or fiscal policy. Whether policymakers should intervene in practice, however, is a more difficult question that entails various political as well as economic judgments.

posted by iambrianfu [ 8:36 AM ] <$BlogItemComments$>

Keynesian economics is a theory of total spending in the economy (called aggregate demand) and of its effects on output and inflation. Although the term is used (and abused) to describe many things, six principal tenets seem central to Keynesianism. The first three describe how the economy works.
1. A Keynesian believes that aggregate demand is influenced by a host of economic decisions—both public and private—and sometimes behaves erratically. The public decisions include, most prominently, those on monetary and fiscal (i.e., spending and tax) policy. Some decades ago, economists heatedly debated the relative strengths of monetary and fiscal policy, with some Keynesians arguing that monetary policy is powerless, and some monetarists arguing that fiscal policy is powerless. Both of these are essentially dead issues today. Nearly all Keynesians and monetarists now believe that both fiscal and monetary policy affect aggregate demand. A few economists, however, believe in what is called debt neutrality—the doctrine that substitutions of government borrowing for taxes have no effects on total demand (more on this below).
2. According to Keynesian theory, changes in aggregate demand, whether anticipated or unanticipated, have their greatest short-run impact on real output and employment, not on prices. This idea is portrayed, for example, in Phillips curves that show inflation changing only slowly when unemployment changes. Keynesians believe the short run lasts long enough to matter. They often quote Keynes's famous statement "In the long run, we are all dead" to make the point.
Anticipated monetary policy (that is, policies that people expect in advance) can produce real effects on output and employment only if some prices are rigid—if nominal wages (wages in dollars, not in real purchasing power), for example, do not adjust instantly. Otherwise, an injection of new money would change all prices by the same percentage. So Keynesian models generally either assume or try to explain rigid prices or wages. Rationalizing rigid prices is hard to do because, according to standard microeconomic theory, real supplies and demands do not change if all nominal prices rise or fall proportionally.
But Keynesians believe that, because prices are somewhat rigid, fluctuations in any component of spending—consumption, investment, or government expenditures—cause output to fluctuate. If government spending increases, for example, and all other components of spending remain constant, then output will increase. Keynesian models of economic activity also include a so-called multiplier effect. That is, output increases by a multiple of the original change in spending that caused it. Thus, a $10 billion increase in government spending could cause total output to rise by $15 billion (a multiplier of 1.5) or by $5 billion (a multiplier of 0.5). Contrary to what many people believe, Keynesian analysis does not require that the multiplier exceed 1.0. For Keynesian economics to work, however, the multiplier must be greater than zero.
3. Keynesians believe that prices and, especially, wages respond slowly to changes in supply and demand, resulting in shortages and surpluses, especially of labor. Even though monetarists are more confident than Keynesians in the ability of markets to adjust to changes in supply and demand, many monetarists accept the Keynesian position on this matter. Milton Friedman, for example, the most prominent monetarist, has written: "Under any conceivable institutional arrangements, and certainly under those that now prevail in the United States, there is only a limited amount of flexibility in prices and wages." In current parlance, that would certainly be called a Keynesian position.
No policy prescriptions follow from these three beliefs alone. And many economists who do not call themselves Keynesian—including most monetarists—would, nevertheless, accept the entire list. What distinguishes Keynesians from other economists is their belief in the following three tenets about economic policy.
4. Keynesians do not think that the typical level of unemployment is ideal—partly because unemployment is subject to the caprice of aggregate demand, and partly because they believe that prices adjust only gradually. In fact, Keynesians typically see unemployment as both too high on average and too variable, although they know that rigorous theoretical justification for these positions is hard to come by. Keynesians also feel certain that periods of recession or depression are economic maladies, not efficient market responses to unattractive opportunities. (Monetarists, as already noted, have a deeper belief in the invisible hand.)
5. Many, but not all, Keynesians advocate activist stabilization policy to reduce the amplitude of the business cycle, which they rank among the most important of all economic problems. Here Keynesians and monetarists (and even some conservative Keynesians) part company by doubting either the efficacy of stabilization policy or the wisdom of attempting it.
This does not mean that Keynesians advocate what used to be called fine-tuning—adjusting government spending, taxes, and the money supply every few months to keep the economy at full employment. Almost all economists, including most Keynesians, now believe that the government simply cannot know enough soon enough to fine-tune successfully. Three lags make it unlikely that fine-tuning will work. First, there is a lag between the time that a change in policy is required and the time that the government recognizes this. Second, there is a lag between when the government recognizes that a change in policy is required and when it takes action. In the United States, this lag is often very long for fiscal policy because Congress and the administration must first agree on most changes in spending and taxes. The third lag comes between the time that policy is changed and when the changes affect the economy. This, too, can be many months. Yet many Keynesians still believe that more modest goals for stabilization policy—coarse-tuning, if you will—are not only defensible, but sensible. For example, an economist need not have detailed quantitative knowledge of lags to prescribe a dose of expansionary monetary policy when the unemployment rate is 10 percent or more—as it was in many leading industrial countries in the eighties.
6. Finally, and even less unanimously, many Keynesians are more concerned about combating unemployment than about conquering inflation. They have concluded from the evidence that the costs of low inflation are small. However, there are plenty of anti-inflation Keynesians. Most of the world's current and past central bankers, for example, merit this title whether they like it or not. Needless to say, views on the relative importance of unemployment and inflation heavily influence the policy advice that economists give and that policymakers accept. Keynesians typically advocate more aggressively expansionist policies than non-Keynesians.
Keynesians' belief in aggressive government action to stabilize the economy is based on value judgments and on the beliefs that (a) macroeconomic fluctuations significantly reduce economic well-being, (b) the government is knowledgeable and capable enough to improve upon the free market, and (c) unemployment is a more important problem than inflation.
The long, and to some extent, continuing battle between Keynesians and monetarists has been fought primarily over (b) and (c).
In contrast, the briefer and more recent debate between Keynesians and new classical economists has been fought primarily over (a) and over the first three tenets of Keynesianism—tenets that the monetarists had accepted. New classicals believe that anticipated changes in the money supply do not affect real output; that markets, even the labor market, adjust quickly to eliminate shortages and surpluses; and that business cycles may be efficient. For reasons that will be made clear below, I believe that the "objective" scientific evidence on these matters points strongly in the Keynesian direction.
Before leaving the realm of definition, however, I must underscore several glaring and intentional omissions.
First, I have said nothing about the rational expectations school of thought (see Rational Expectations). Like Keynes himself, many Keynesians doubt that school's view that people use all available information to form their expectations about economic policy. Other Keynesians accept the view. But when it comes to the large issues with which I have concerned myself, nothing much rides on whether or not expectations are rational. Rational expectations do not, for example, preclude rigid prices. Stanford's John Taylor and MIT's Stanley Fischer have constructed rational expectations models with sticky prices that are thoroughly Keynesian by my definition. I should note, though, that some new classicals see rational expectations as much more fundamental to the debate.
The second omission is the hypothesis that there is a "natural rate" of unemployment in the long run. Prior to 1970, Keynesians believed that the long-run level of unemployment depended on government policy, and that the government could achieve a low unemployment rate by accepting a high but steady rate of inflation. In the late sixties Milton Friedman, a monetarist, and Columbia's Edmund Phelps, a Keynesian, rejected the idea of such a long-run trade-off on theoretical grounds. They argued that the only way the government could keep unemployment below what they called the "natural rate" was with macroeconomic policies that would continuously drive inflation higher and higher. In the long run, they argued, the unemployment rate could not be below the natural rate. Shortly thereafter, Keynesians like Northwestern's Robert Gordon presented empirical evidence for Friedman's and Phelps's view. Since about 1972 Keynesians have integrated the "natural rate" of unemployment into their thinking. So the natural rate hypothesis played essentially no role in the intellectual ferment of the 1975-85 period.
Third, I have ignored the choice between monetary and fiscal policy as the preferred instrument of stabilization policy. Economists differ about this and occasionally change sides. By my definition, however, it is perfectly possible to be a Keynesian and still believe either that responsibility for stabilization policy should, in principle, be ceded to the monetary authority or that it is, in practice, so ceded.
Keynesian theory was much denigrated in academic circles from the midseventies until the mideighties. It has staged a strong comeback since then, however. The main reason appears to be that Keynesian economics was better able to explain the economic events of the seventies and eighties than its principal intellectual competitor, new classical economics.
True to its classical roots, new classical theory emphasizes the ability of a market economy to cure recessions by downward adjustments in wages and prices. The new classical economists of the midseventies attributed economic downturns to people's misperceptions about what was happening to relative prices (such as real wages). Misperceptions would arise, they argued, if people did not know the current price level or inflation rate. But such misperceptions should be fleeting and surely cannot be large in societies in which price indexes are published monthly and the typical monthly inflation rate is under 1 percent. Therefore, economic downturns, by the new classical view, should be mild and brief. Yet during the eighties most of the world's industrial economies endured deep and long recessions. Keynesian economics may be theoretically untidy, but it certainly is a theory that predicts periods of persistent, involuntary unemployment.
According to new classical theory, a correctly perceived decrease in the growth of the money supply should have only small effects, if any, on real output. Yet when the Federal Reserve and the Bank of England announced that monetary policy would be tightened to fight inflation, and then made good on their promises, severe recessions followed in each country. New classicals might claim that the tightening was unanticipated (because people did not believe what the monetary authorities said). Perhaps it was in part. But surely the broad contours of the restrictive policies were anticipated, or at least correctly perceived as they unfolded. Old-fashioned Keynesian theory, which says that any monetary restriction is contractionary because firms and individuals are locked into fixed-price contracts, not inflation-adjusted ones, seems more consistent with actual events.
An offshoot of new classical theory formulated by Harvard's Robert Barro is the idea of debt neutrality. Barro argues that inflation, unemployment, real GNP, and real national saving should not be affected by whether the government finances its spending with high taxes and low deficits or with low taxes and high deficits. Because people are rational, he argues, they will correctly perceive that low taxes and high deficits today must mean higher future taxes for them and their heirs. They will, Barro argues, cut consumption and increase their saving by one dollar for each dollar increase in future tax liabilities. Thus, a rise in private saving should offset any increase in the government's deficit. Naïve Keynesian analysis, by contrast, sees an increased deficit, with government spending held constant, as an increase in aggregate demand. If, as happened in the United States, the stimulus to demand is nullified by contractionary monetary policy, real interest rates should rise strongly. There is no reason, in the Keynesian view, to expect the private saving rate to rise.
The massive U.S. tax cuts between 1981 and 1984 provided something approximating a laboratory test of these alternative views. What happened? The private saving rate did not rise. Real interest rates soared, even though a surprisingly large part of the shock was absorbed by exchange rates rather than by interest rates. With fiscal stimulus offset by monetary contraction, real GNP growth was approximately unaffected; it grew at about the same rate as it had in the recent past. Again, this all seems more consistent with Keynesian than with new classical theory.
Finally, there was the European depression of the eighties, which was the worst since the depression of the thirties. The Keynesian explanation is straightforward. Governments, led by the British and German central banks, decided to fight inflation with highly restrictive monetary and fiscal policies. The anti-inflation crusade was strengthened by the European Monetary System, which, in effect, spread the stern German monetary policy all over Europe. The new classical school has no comparable explanation. New classicals, and conservative economists in general, argue that European governments interfere more heavily in labor markets (with high unemployment benefits, for example, and restrictions on firing workers). But most of these interferences were in place in the early seventies, when unemployment was extremely low

posted by iambrianfu [ 8:35 AM ] <$BlogItemComments$>