《宏观经济学》课程教学资源（英文版）Lecture 5-14 Stabilization Policy.pdf_大学文库

User JOEWA:Job EFF01430:6264_ch14:Pg 380:24427#/eps at 100% *24427* Mon, Feb 18, 2002 1:02 AM How should government policymakers respond to the business cycle? The two quotations above—the first from a former chairman of the Federal Reserve, the second from a prominent critic of the Fed—show the diversity of opinion over how this question is best answered. Some economists, such as William McChesney Martin, view the economy as inherently unstable.They argue that the economy experiences frequent shocks to aggregate demand and aggregate supply. Unless policymakers use monetary and fiscal policy to stabilize the economy, these shocks will lead to unnecessary and inefficient fluctuations in output, unemployment, and inflation.According to the popular saying, macroeconomic policy should “lean against the wind,’’ stimulating the economy when it is depressed and slowing the economy when it is overheated. Other economists, such as Milton Friedman, view the economy as naturally stable. They blame bad economic policies for the large and inefficient fluctuations we have sometimes experienced.They argue that economic policy should not try to “fine-tune’’ the economy. Instead, economic policymakers should admit their limited abilities and be satisfied if they do no harm. This debate has persisted for decades, with numerous protagonists advancing various arguments for their positions.The fundamental issue is how policymakers should use the theory of short-run economic fluctuations developed in the Stabilization Policy 14 CHAPTER The Federal Reserve’s job is to take away the punch bowl just as the party gets going. — William McChesney Martin What we need is not a skilled monetary driver of the economic vehicle continuously turning the steering wheel to adjust to the unexpected irregularities of the route, but some means of keeping the monetary passenger who is in the back seat as ballast from occasionally leaning over and giving the steering wheel a jerk that threatens to send the car off the road. — Milton Friedman FOURTEEN 380 |

Worth: Mankiw Economics 5e CHAPTER 14 Stabilization Policy 381 preceding chapters In this chapter we ask two questions that arise in this debate. First, should monetary and fiscal policy take an active role in trying to stabilize the economy, or should policy remain passive? Second, should policymakers be free to use their discretion in responding to changing economic conditions, or should they be committed to following a fixed policy rule 74-1 Should Policy Be Active or Passive? Policymakers in the federal government view economic stabilization as one of their primary responsibilities. The analysis of macroeconomic policy is a regula duty of the Council of Economic Advisers, the Congressional Budget Office, the Federal Reserve, and other government agencies. When Congress or the presi dent is considering a major change in fiscal policy, or when the Federal Reserve is considering a major change in monetary policy, foremost in the discussion are how the change will influence inflation and unemployment and whether aggre demand needs to be stimulated or restrained Although the government has long conducted monetary and fiscal policy, the view that it should use these policy instruments to try to stabilize the economy is more recent. The Employment Act of 1946 was a key piece of legislation in which the government first held itself accountable for macroeconomic perfor mance. The act states that "it is the continuing policy and responsibility of the Federal Government to .. promote full employment and production. "This law was written when the memory of the Great Depression was still fresh. The law- makers who wrote it believed, as many economists do, that in the absence of an active government role in the economy, events such as the great Depression could occur regularly. To many economists the case for active government policy is clear and simple. Recessions are periods of high unemployment, low incomes, and increased eco- nomic hardship. The model of aggregate demand and aggregate supply shows how shocks to the economy can cause recessions. It also shows how monetary and fis- cal policy can prevent recessions by responding to these shocks. These economists consider it wasteful not to use these policy instruments to stabilize the economy. Dther economists are critical of the governments attempts to stabilize the economy. These critics argue that the government should take a hands-off ap- proach to macroeconomic policy. At first, this view might seem surprising. If our model shows how to prevent or reduce the severity of recessions, why do these critics want the government to refrain from using monetary and fiscal policy for economic stabilization? To find out, let's consider some of their arguments Lags in the Implementation and Effects of policies Economic stabilization would be easy if the effects of policy were immediate Making policy would be like driving a car: policymakers would simply adjust heir instruments to keep the economy on the desired path User JoENA: Job EFFo1430: 6264_ch14: Pg 381: 27867#/eps at 100s Mon,Feb18,20021:024M

User JOEWA:Job EFF01430:6264_ch14:Pg 381:27867#/eps at 100% *27867* Mon, Feb 18, 2002 1:02 AM preceding chapters. In this chapter we ask two questions that arise in this debate. First, should monetary and fiscal policy take an active role in trying to stabilize the economy, or should policy remain passive? Second, should policymakers be free to use their discretion in responding to changing economic conditions, or should they be committed to following a fixed policy rule? 14-1 Should Policy Be Active or Passive? Policymakers in the federal government view economic stabilization as one of their primary responsibilities.The analysis of macroeconomic policy is a regular duty of the Council of Economic Advisers, the Congressional Budget Office, the Federal Reserve, and other government agencies.When Congress or the president is considering a major change in fiscal policy, or when the Federal Reserve is considering a major change in monetary policy, foremost in the discussion are how the change will influence inflation and unemployment and whether aggregate demand needs to be stimulated or restrained. Although the government has long conducted monetary and fiscal policy, the view that it should use these policy instruments to try to stabilize the economy is more recent. The Employment Act of 1946 was a key piece of legislation in which the government first held itself accountable for macroeconomic performance.The act states that “it is the continuing policy and responsibility of the Federal Government to . . . promote full employment and production.’’This law was written when the memory of the Great Depression was still fresh.The lawmakers who wrote it believed, as many economists do, that in the absence of an active government role in the economy, events such as the Great Depression could occur regularly. To many economists the case for active government policy is clear and simple. Recessions are periods of high unemployment, low incomes, and increased economic hardship.The model of aggregate demand and aggregate supply shows how shocks to the economy can cause recessions. It also shows how monetary and fiscal policy can prevent recessions by responding to these shocks.These economists consider it wasteful not to use these policy instruments to stabilize the economy. Other economists are critical of the government’s attempts to stabilize the economy. These critics argue that the government should take a hands-off approach to macroeconomic policy.At first, this view might seem surprising. If our model shows how to prevent or reduce the severity of recessions, why do these critics want the government to refrain from using monetary and fiscal policy for economic stabilization? To find out, let’s consider some of their arguments. Lags in the Implementation and Effects of Policies Economic stabilization would be easy if the effects of policy were immediate. Making policy would be like driving a car: policymakers would simply adjust their instruments to keep the economy on the desired path. CHAPTER 14 Stabilization Policy | 381

Worth: Mankiw Economics 5e 382 PART V Macroeconomic Policy Debates Making economic policy, however, is less like driving a car than it is like pilot ing a large ship. car cna anges direction almost immediately after the steering wheel is turned. By contrast, a ship changes course long after the pilot adjusts the dder, and once the ship starts to turn, it continues turning long after the rudder is set back to normal. a novice pilot is likely to oversteer and, after noticing the mistake, overreact by steering too much in the opposite direction. The ship's path could become unstable, as the novice responds to previous mistakes by making larger and larger corrections Like a ship's pilot, economic policymakers face the problem of long lags In- deed, the problem for policymakers is even more difficult, because the lengths of the lags are hard to predict. These long and variable lags greatly complicate the conduct of monetary and fiscal policy Economists distinguish between two lags in the conduct of stabilization policy: the inside lag and the outside lag. The inside lag is the time between a shock to the economy and the policy action responding to that shock. This lag arises be cause it takes time for policymakers first to recognize that a shock has occurred and then to put appropriate policies into effect. The outside lag is the time be tween a policy action and its influence on the economy. This lag arises because policies do not immediately influence spending, income, and employment. A long inside lag is a central problem with using fiscal policy for economic stabilization. This is especially true in the United States, where changes in spend- ing or taxes require the approval of the president and both houses of Congress The slow and cumbersome legislative process often leads to delays, which make fiscal policy an imprecise tool for stabilizing the economy. This inside lag is shorter in countries with parliamentary systems, such as the United Kingdom, because there the party in power can often enact policy changes more rapidly c Monetary policy has a much shorter inside lag than fiscal policy, because tral bank can decide on and implement a policy change in less than a day, but monetary policy has a substantial outside lag. Monetary policy works by chang- ing the money supply and thereby interest rates, which in turn influence invest- ment. But many firms make investment plans far in advance. Therefore, a change in monetary policy is thought not to affect economic activity until about six months after it is made The long and variable lags associated with monetary and fiscal policy certainly make stabilizing the economy more difficult. Advocates of passive policy argue that, because of these lags, successful stabilization policy is almost impossible. Indeed, at npts to stabilize the economy can be destabilizing. Suppose that the economy's condition changes between the beginning of a policy action and its impact on the economy. In this case, active policy may end up stimulating the economy when it is overheated or depressing the economy when it is cooling off. Advocates of active policy admit that such lags do require policymakers to be cautious. But, they argue, these lags do not necessarily mean that policy should be completely passive, espe cially in the face of a severe and protracted economic downturn Some policies, called automatic stabilizers, are designed to reduce the lags as- sociated with stabilization policy. Automatic stabilizers are policies that stimulate or depress the economy when necessary without any deliberate policy change. For User JOENA: Job EFF01430: 6264_ch14: Pg 382: 27868 #/eps at 100s Mon,Feb18,20021:024M

User JOEWA:Job EFF01430:6264_ch14:Pg 382:27868#/eps at 100% *27868* Mon, Feb 18, 2002 1:02 AM Making economic policy, however, is less like driving a car than it is like piloting a large ship. A car changes direction almost immediately after the steering wheel is turned. By contrast, a ship changes course long after the pilot adjusts the rudder, and once the ship starts to turn, it continues turning long after the rudder is set back to normal.A novice pilot is likely to oversteer and, after noticing the mistake, overreact by steering too much in the opposite direction.The ship’s path could become unstable, as the novice responds to previous mistakes by making larger and larger corrections. Like a ship’s pilot, economic policymakers face the problem of long lags. Indeed, the problem for policymakers is even more difficult, because the lengths of the lags are hard to predict.These long and variable lags greatly complicate the conduct of monetary and fiscal policy. Economists distinguish between two lags in the conduct of stabilization policy: the inside lag and the outside lag.The inside lag is the time between a shock to the economy and the policy action responding to that shock.This lag arises because it takes time for policymakers first to recognize that a shock has occurred and then to put appropriate policies into effect.The outside lag is the time between a policy action and its influence on the economy.This lag arises because policies do not immediately influence spending, income, and employment. A long inside lag is a central problem with using fiscal policy for economic stabilization.This is especially true in the United States, where changes in spending or taxes require the approval of the president and both houses of Congress. The slow and cumbersome legislative process often leads to delays, which make fiscal policy an imprecise tool for stabilizing the economy. This inside lag is shorter in countries with parliamentary systems, such as the United Kingdom, because there the party in power can often enact policy changes more rapidly. Monetary policy has a much shorter inside lag than fiscal policy, because a central bank can decide on and implement a policy change in less than a day, but monetary policy has a substantial outside lag. Monetary policy works by changing the money supply and thereby interest rates, which in turn influence investment. But many firms make investment plans far in advance.Therefore, a change in monetary policy is thought not to affect economic activity until about six months after it is made. The long and variable lags associated with monetary and fiscal policy certainly make stabilizing the economy more difficult.Advocates of passive policy argue that, because of these lags, successful stabilization policy is almost impossible. Indeed, attempts to stabilize the economy can be destabilizing. Suppose that the economy’s condition changes between the beginning of a policy action and its impact on the economy. In this case, active policy may end up stimulating the economy when it is overheated or depressing the economy when it is cooling off. Advocates of active policy admit that such lags do require policymakers to be cautious. But, they argue, these lags do not necessarily mean that policy should be completely passive, especially in the face of a severe and protracted economic downturn. Some policies, called automatic stabilizers, are designed to reduce the lags associated with stabilization policy.Automatic stabilizers are policies that stimulate or depress the economy when necessary without any deliberate policy change. For 382 | PART V Macroeconomic Policy Debates

Worth: Mankiw Economics 5e CHAPTER 14 Stabilization Policy 383 example, the system of income taxes automatically reduces taxes when the economy goes into a recession, without any change in the tax laws, because individuals and corporations pay less tax when their incomes fall. Similarly, the unemployment insurance and welfare systems automatically raise transfer payments when the econ- omy moves into a recession, because more people apply for benefits. One can view these automatic stabilizers as a type of fiscal policy without any inside lag The Difficult Job of Economic Forecasting Because policy influences the economy only after a long lag, successful stabilization policy requires the ability to predict accurately future economic conditions. If we cannot predict whether the economy will be in a boom or a recession in six months or a year, we cannot evaluate whether monetary and fiscal policy should now be try ing to expand or contract aggregate demand. Unfortu nately, economic developments are often unpredictabl at least given our current understanding of the economy. One way forecasters try to look ahead is with lead ing indicators. a leading indicator is a data series that fluctuates in advance of the economy. A large fall in a leading indicator signals that a recession is more likely Another way forecasters look ahead is with macro- conometric models, which have been developed both by overtime ent agencies and by private firms for forecast- It's true. Caesar. Rome is declining but I ing and policy analysis. As we discussed in Chapter 11, expect it to pick up in the next quarter What's in the Index of Leading Economic Indicators? Each month the Conference Board, a private! 3. New orders for consumer goods and materi economics research group, announces the index als, adjusted for of leading economic indicators. This index is made upi 4. Vendor performance. This is a measure of from 10 data series that are often used to fore- the number of companies receiving slower cast changes in economic activity about six to deliveries from suppliers nine months ahead. Here is a list of the series Can you explain why each of these might help 5. New orders, nondefense capital goods predict changes in real GDP? 6. New building permits issued. 1. Average workweek of production workers in 7. Index of stock prices 8. Money supply(M2), adjusted for inflation 2. Average initial weekly claims for unemploy.i 9. Interest rate spread: the yield spread be- ment insurance. This series is inverted in tween 10-year Tr computing the index, so that a decrease Treasury bills the series raises the index 10. Index of consumer expectations User JoENA: Job EFFo1430: 6264_ch14: Pg 383: 27869#/eps at 100sl Mon,Feb18,20021:024M

User JOEWA:Job EFF01430:6264_ch14:Pg 383:27869#/eps at 100% *27869* Mon, Feb 18, 2002 1:02 AM example,the system of income taxes automatically reduces taxes when the economy goes into a recession, without any change in the tax laws, because individuals and corporations pay less tax when their incomes fall. Similarly, the unemploymentinsurance and welfare systems automatically raise transfer payments when the economy moves into a recession, because more people apply for benefits. One can view these automatic stabilizers as a type of fiscal policy without any inside lag. The Difficult Job of Economic Forecasting Because policy influences the economy only after a long lag,successful stabilization policy requires the ability to predict accurately future economic conditions. If we cannot predict whether the economy will be in a boom or a recession in six months or a year,we cannot evaluate whether monetary and fiscal policy should now be trying to expand or contract aggregate demand. Unfortunately, economic developments are often unpredictable, at least given our current understanding of the economy. One way forecasters try to look ahead is with leading indicators.A leading indicator is a data series that fluctuates in advance of the economy. A large fall in a leading indicator signals that a recession is more likely. Another way forecasters look ahead is with macroeconometric models, which have been developed both by government agencies and by private firms for forecasting and policy analysis. As we discussed in Chapter 11, CHAPTER 14 Stabilization Policy | 383 “It’s true, Caesar. Rome is declining, but I expect it to pick up in the next quarter.” Drawing by Dana Fradon; © 1988 The New Yorker Magazine, Inc. FYI Each month the Conference Board, a private economics research group, announces the index of leading economic indicators. This index is made up from 10 data series that are often used to forecast changes in economic activity about six to nine months ahead. Here is a list of the series. Can you explain why each of these might help predict changes in real GDP? 1. Average workweek of production workers in manufacturing. 2. Average initial weekly claims for unemployment insurance. This series is inverted in computing the index, so that a decrease in the series raises the index. What’s in the Index of Leading Economic Indicators? 3. New orders for consumer goods and materials, adjusted for inflation. 4. Vendor performance. This is a measure of the number of companies receiving slower deliveries from suppliers. 5. New orders, nondefense capital goods. 6. New building permits issued. 7. Index of stock prices. 8. Money supply (M2), adjusted for inflation. 9. Interest rate spread: the yield spread between 10-year Treasury notes and 3-month Treasury bills. 10. Index of consumer expectations

Worth: Mankiw Economics 5e CHAPTER 14 Stabilization Policy 385 Like weather forecasts, economic forecasts are a crucial input to private and public decisionmaking. Business executives rely on economic forecasts when de- ciding how much to produce and how much to invest in plant and equipment Government policymakers also rely on them when developing economic poli- cies. Yet also like weather forecasts, economic forecasts are far from precise The most severe economic downturn in U.S. history, the Great Depression of the 1930s, caught economic forecasters completely by surprise. Even after the stock market crash of 1929, they remained confident that the economy would not suffer a substantial setback. In late 1931, when the economy was clearly in bad shape, the eminent economist Irving Fisher predicted that it would recover quickly. Subsequent events showed that these forecasts were much too optimistic. I Figure 14-1 shows how economic forecasters did during the recession of 1982, the most severe economic downturn in the United States since the Great Depres sion. This figure shows the actual unemployment rate(in red) and six attempts to predict it for the following five quarters (in blue). You can see that the forecasters did well predicting unemployment one quarter ahead. The more distant forecasts, how- ever,were often inaccurate. For example, in the second quarter of 1981, forecasters were predicting little change in the unemployment rate over the next five quarters yet only two quarters later unemployment began to rise sharply. The rise in unem- ployment to almost 11 percent in the fourth quarter of 1982 caught the forecasters by surprise. After the depth of the recession became apparent, the forecasters failed to predict how rapid the subsequent decline in unemployment would be These two episodes--the Great Depression and the recession of 1982show that many of the most dramatic economic events are unpredictable. Although private and public decisionmakers have little choice but to rely on economic forecasts, they must always keep in mind that these forecasts come with a large margin of error. Ignorance, Expectations, and the Lucas Critique The prominent economist Robert Lucas once wrote, " As an advice-giving pro- fession we are in way over our heads. Even many of those who advise policy- makers would agree with this assessment. Economics is a young science, and there is still much that we do not know. Economists cannot be completely confi- dent when they assess the effects of alternative policies. This ignorance suggests that economists should be cautious when offering policy advice Although economists knowledge is limited about many topics, Lucas has em- of the a crucial role in the economy because they influence all sorts of economic behav- ior. For instance, households decide how much to consume based on expectations Kathryn M. Dominguez, Ray C. Fair, and Matthew D. Shapiro, "Forecasting the Depressio Harvard Versus Yale, "American Economic Review 78( September 1988): 595-612. This article shows how badly economic forecasters did during the Great Depression, and it argues that they could not ave done any better with the modern forecasting techniques available today User JoEkA: Job EFFo1430: 6264_ch14: Pg 385: 27871#/eps at 1004 Mon,Feb18,20021:024M

User JOEWA:Job EFF01430:6264_ch14:Pg 385:27871#/eps at 100% *27871* Mon, Feb 18, 2002 1:02 AM CHAPTER 14 Stabilization Policy | 385 Like weather forecasts, economic forecasts are a crucial input to private and public decisionmaking. Business executives rely on economic forecasts when deciding how much to produce and how much to invest in plant and equipment. Government policymakers also rely on them when developing economic policies.Yet also like weather forecasts, economic forecasts are far from precise. The most severe economic downturn in U.S. history, the Great Depression of the 1930s, caught economic forecasters completely by surprise. Even after the stock market crash of 1929, they remained confident that the economy would not suffer a substantial setback. In late 1931, when the economy was clearly in bad shape, the eminent economist Irving Fisher predicted that it would recover quickly.Subsequent events showed that these forecasts were much too optimistic.1 Figure 14-1 shows how economic forecasters did during the recession of 1982, the most severe economic downturn in the United States since the Great Depression.This figure shows the actual unemployment rate (in red) and six attempts to predict it for the following five quarters (in blue).You can see that the forecasters did well predicting unemployment one quarter ahead.The more distant forecasts, however, were often inaccurate. For example, in the second quarter of 1981, forecasters were predicting little change in the unemployment rate over the next five quarters; yet only two quarters later unemployment began to rise sharply.The rise in unemployment to almost 11 percent in the fourth quarter of 1982 caught the forecasters by surprise.After the depth of the recession became apparent, the forecasters failed to predict how rapid the subsequent decline in unemployment would be. These two episodes—the Great Depression and the recession of 1982—show that many of the most dramatic economic events are unpredictable. Although private and public decisionmakers have little choice but to rely on economic forecasts, they must always keep in mind that these forecasts come with a large margin of error. 1 Kathryn M. Dominguez, Ray C. Fair, and Matthew D. Shapiro, “Forecasting the Depression: Harvard Versus Yale,’’ American Economic Review 78 (September 1988): 595–612.This article shows how badly economic forecasters did during the Great Depression, and it argues that they could not have done any better with the modern forecasting techniques available today. Ignorance, Expectations, and the Lucas Critique The prominent economist Robert Lucas once wrote,“As an advice-giving profession we are in way over our heads.’’ Even many of those who advise policymakers would agree with this assessment. Economics is a young science, and there is still much that we do not know. Economists cannot be completely confi- dent when they assess the effects of alternative policies.This ignorance suggests that economists should be cautious when offering policy advice. Although economists’ knowledge is limited about many topics, Lucas has emphasized the issue of how people form expectations of the future.Expectations play a crucial role in the economy because they influence all sorts of economic behavior. For instance, households decide how much to consume based on expectations

Worth: Mankiw Economics 5e 386 PART V Macroeconomic Policy Debates of future income, and firms decide how much to invest based on expectations of future profitability. These expectations depend on many things, including the eco- nomic policies being pursued by the government. Thus, when policymakers esti- mate the effect of any policy change, they need to know how people's expectations will respond to the policy change. Lucas has argued that traditional methods of policy evaluation- such as those that rely on standard macroeconometric mod- els--do not adequately take into account this impact of policy on expectations This criticism of traditional policy evaluation is known as the Lucas critique o: An important example of the Lucas critique arises in the analysis of disinfla- nAs you may recall from Chapter 13, the cost of reducing inflation is often measured by the sacrifice ratio, which is the number of percentage points of GDP that must be forgone to reduce inflation by 1 percentage point. Because hese estimates of the sacrifice ratio are often large, they have led some econo- mists to argue that policymakers should learn to live with inflation, rather than Incur the large cost of reducing it. According to advocates of the rational-expectations approach, however, these es- timates of the sacrifice ratio are unreliable because they are subject to the Lucas cri- tique. Traditional estimates of the sacrifice ratio are based on adaptive expectations, that is, on the assumption that expected inflation depends on past inflation. Adaptive expectations may be a reasonable premise in some circumstances, but if the policy makers make a credible change in policy, workers and firms setting wages and prices will rationally respond by adjusting their expectations of inflation appropriately. This change in inflation expectations will quickly alter the short-run tradeoff between fation and unemployment. As a result, reducing inflation can potentially be much less costly than is suggested by traditional estimates of the sacrifice ratio The Lucas critique leaves us with two lessons. The narrow lesson is that econo- mists evaluating alternative policies need to consider how policy affects expecta- nd, thereby, behavior. The broad lesson is that policy evaluation is hard,so economists engaged in this task should be sure to show the requisite humility. The historical record In judging whethe er government po olicy should play an active or passive role in the economy, we must give some weight to the historical record. If the economy has experienced many large shocks to aggregate supply and aggregate demand, and if policy has successfully insulated the economy from these shocks, then the case for active policy should be clear. Conversely, if the economy has experienced few rge shocks, and if the fuctuations we have observed can be traced to inept eco- omic policy, then the case for passive policy should be clear. In other words,our view of stabilization policy should be influenced by whether policy has histori- cally been stabilizing or destabilizing. For this reason, the debate over macroeco- nomic policy frequently turns into a debate over macroeconomic history. Yet history does not settle the debate over stabilization policy. Disagree ments over history arise because it is not easy to identify the sources of Robert E. Lucas, Jr, "Econometric Policy Evaluation: A Critique, " Carnegie Rochester Conference on Public Policy 1(Amsterdam: North-Holland, 1976), 19-46. User JoENA: Job EFFo1430: 6264_ch14: Pg 386: 27872#/eps at 100s Mon,Feb18,20021:024M

User JOEWA:Job EFF01430:6264_ch14:Pg 386:27872#/eps at 100% *27872* Mon, Feb 18, 2002 1:02 AM of future income, and firms decide how much to invest based on expectations of future profitability.These expectations depend on many things, including the economic policies being pursued by the government.Thus, when policymakers estimate the effect of any policy change,they need to know how people’s expectations will respond to the policy change. Lucas has argued that traditional methods of policy evaluation—such as those that rely on standard macroeconometric models—do not adequately take into account this impact of policy on expectations. This criticism of traditional policy evaluation is known as the Lucas critique. 2 An important example of the Lucas critique arises in the analysis of disinflation. As you may recall from Chapter 13, the cost of reducing inflation is often measured by the sacrifice ratio, which is the number of percentage points of GDP that must be forgone to reduce inflation by 1 percentage point. Because these estimates of the sacrifice ratio are often large, they have led some economists to argue that policymakers should learn to live with inflation, rather than incur the large cost of reducing it. According to advocates of the rational-expectations approach, however, these estimates of the sacrifice ratio are unreliable because they are subject to the Lucas critique.Traditional estimates of the sacrifice ratio are based on adaptive expectations, that is,on the assumption that expected inflation depends on past inflation.Adaptive expectations may be a reasonable premise in some circumstances, but if the policymakers make a credible change in policy,workers and firms setting wages and prices will rationally respond by adjusting their expectations of inflation appropriately.This change in inflation expectations will quickly alter the short-run tradeoff between inflation and unemployment.As a result, reducing inflation can potentially be much less costly than is suggested by traditional estimates of the sacrifice ratio. The Lucas critique leaves us with two lessons.The narrow lesson is that economists evaluating alternative policies need to consider how policy affects expectations and, thereby, behavior.The broad lesson is that policy evaluation is hard, so economists engaged in this task should be sure to show the requisite humility. The Historical Record In judging whether government policy should play an active or passive role in the economy, we must give some weight to the historical record. If the economy has experienced many large shocks to aggregate supply and aggregate demand, and if policy has successfully insulated the economy from these shocks, then the case for active policy should be clear. Conversely, if the economy has experienced few large shocks, and if the fluctuations we have observed can be traced to inept economic policy, then the case for passive policy should be clear. In other words, our view of stabilization policy should be influenced by whether policy has historically been stabilizing or destabilizing. For this reason, the debate over macroeconomic policy frequently turns into a debate over macroeconomic history. Yet history does not settle the debate over stabilization policy. Disagreements over history arise because it is not easy to identify the sources of 386 | PART V Macroeconomic Policy Debates 2 Robert E. Lucas, Jr., “Econometric Policy Evaluation: A Critique,’’ Carnegie Rochester Conference on Public Policy 1 (Amsterdam: North-Holland, 1976), 19–46

Worth: Mankiw Economics 5e CHAPTER 14 Stabilization Policy 387 economic fluctuations. The historical record often permits more than one Interpretation. The Great Depression is a case in point. Economists' views on macroeconomic policy are often related to their views on the cause of the Depression. Some econ- omists believe that a large contractionary shock to private spending caused the Depression. They assert that policymakers should have responded by stimulating aggregate demand. Other economists believe that the large fall in the money sup- ply caused the Depression. They assert that the Depression would have been avoided if the Fed had been pursuing a passive monetary policy of increasing the money supply at a steady rate. Hence, depending on one's beliefs about its cause, the great Depression can be viewed either as an example of why active monetary nd fiscal policy is necessary or as an example of why it is dangerous CASE STUDY Is the Stabilization of the Economy a Figment of the Data? Keynes wrote The General Theory in the 1930s, and in the wake of the Keynesian revolution, governments around the world began to view economic stabilization as a primary responsibility. Some economists believe that the development of Keynesian theory has had a profound influence on the behavior of the economy. Comparing data from before World War I and after World War IL, they find that real GDP and unemployment have become much more stable. This, some Keynes- ians claim, is the best argument for active stabilization policy: it has worked. In a series of provocative and infuential papers, economist Christina Romer challenged this assessment of the historical record. She argues that the mea ared reduction in volatility reflects not an improvement in economic policy and performance but rather an improvement in the economic data. The older data are much less accurate than the newer data. Romer claims that the higher volatil- ity of unemployment and real GDP reported for the period before World War I is largely a figment of the data. Romer uses various techniques to make her case. One is to construct more accurate data for the earlier period. This task is difficult because data sources are not readily available. A second way is to construct less accurate data for the recent period-that is, data that are comparable to the older data and thus suffer from the same imperfections. After constructing new ""bad"data, Romer finds that the recent period appears almost as volatile as the early period, suggesting that the volatility of the early period may be largely an artifact of data construction Romer's work is part of the continuing debate over whether macroeconomic policy has improved the performance of the economy. Although her work remains controversial, most economists now believe that the economy in the aftermath of the Keynesian revolution was only slightly more stable than it had been before 3 Christina D Romer, "Spurious Volatility in Historical Unemployment Data, "Journal of Political Economy a Figment of the Data? "American Economic Review 76(June 1986): 314-337 he postwar Economy 94(February 1986): 1-37; and Christina D. Romer, ""Is the Stabilization of User JoENA: Job EFFo1430: 6264_ch14: Pg 387: 27873#/eps at 100sl Mon,Feb18,20021:034M

User JOEWA:Job EFF01430:6264_ch14:Pg 387:27873#/eps at 100% *27873* Mon, Feb 18, 2002 1:03 AM economic fluctuations. The historical record often permits more than one interpretation. The Great Depression is a case in point. Economists’ views on macroeconomic policy are often related to their views on the cause of the Depression. Some economists believe that a large contractionary shock to private spending caused the Depression.They assert that policymakers should have responded by stimulating aggregate demand. Other economists believe that the large fall in the money supply caused the Depression. They assert that the Depression would have been avoided if the Fed had been pursuing a passive monetary policy of increasing the money supply at a steady rate. Hence, depending on one’s beliefs about its cause, the Great Depression can be viewed either as an example of why active monetary and fiscal policy is necessary or as an example of why it is dangerous. CHAPTER 14 Stabilization Policy | 387 CASE STUDY Is the Stabilization of the Economy a Figment of the Data? Keynes wrote The General Theory in the 1930s, and in the wake of the Keynesian revolution, governments around the world began to view economic stabilization as a primary responsibility. Some economists believe that the development of Keynesian theory has had a profound influence on the behavior of the economy. Comparing data from before World War I and after World War II, they find that real GDP and unemployment have become much more stable.This,some Keynesians claim, is the best argument for active stabilization policy: it has worked. In a series of provocative and influential papers, economist Christina Romer has challenged this assessment of the historical record. She argues that the measured reduction in volatility reflects not an improvement in economic policy and performance but rather an improvement in the economic data. The older data are much less accurate than the newer data. Romer claims that the higher volatility of unemployment and real GDP reported for the period before World War I is largely a figment of the data. Romer uses various techniques to make her case. One is to construct more accurate data for the earlier period.This task is difficult because data sources are not readily available. A second way is to construct less accurate data for the recent period—that is, data that are comparable to the older data and thus suffer from the same imperfections. After constructing new “bad’’ data, Romer finds that the recent period appears almost as volatile as the early period, suggesting that the volatility of the early period may be largely an artifact of data construction. Romer’s work is part of the continuing debate over whether macroeconomic policy has improved the performance of the economy. Although her work remains controversial, most economists now believe that the economy in the aftermath of the Keynesian revolution was only slightly more stable than it had been before.3 3 Christina D. Romer, “Spurious Volatility in Historical Unemployment Data,’’ Journal of Political Economy 94 (February 1986): 1–37; and Christina D. Romer, “Is the Stabilization of the Postwar Economy a Figment of the Data?’’American Economic Review 76 ( June 1986): 314–334