Modern Macroeconomics in Practice:

理论是如何成为货币政策的(第二部分)

Bernanke et al. (1999) argue that inflation targeting is moving toward a rule-based regime. Their idea (p. 24) is that “inflation targeting requires an accounting to the public of the projected long run implications of its short run policy actions.” This accounting can help ameliorate the time inconsistency problem by ensuring that the long-run implications of short-run policy actions are explicitly taken into account in the policymaking process.

In practice, inflation targeting often involves setting bands of acceptable inflation rates. (See, for example, Bernanke and Mishkin, 1997.) In theoretical models without private information, optimal policy does not involve setting bands, but rather involves specifying exactly what the monetary authority should do in every state. In this sense, such models imply that the monetary authority should have no discretion. Athey, Atkeson, and Kehoe (2005) construct a model in which the monetary authority has private information about the economy and show that the optimal policy allows for limited discretion in that it specifies acceptable ranges for inflation and gives the monetary authority complete discretion within those ranges. In this way, Athey, Atkeson, and Kehoe provide a theoretical rationale for the type of inflation targeting often seen in practice.

Perhaps the most vivid example of both the movement toward independence and the movement toward a rule-based method of policymaking is to be found in the charter of the European Central Bank (ECB). Article 105 of the treaty establishing the central bank states that “the primary objective” of the European System of Central Banks (ESCB) shall be to “maintain price stability.” Article 107 of the treaty emphasizes and protects the independence of the central bank by mandating that “neither the ECB, nor a national central bank, nor any member of their decision-making bodies shall seek or take instructions from Community institutions or bodies, from any government of a Member State or from any other body.” Furthermore, the Maastricht Treaty and the Stability and Growth Pact contain provisions restricting fiscal policies in the member countries in order to make the pursuit of price stability easier.² The change in the conduct of European monetary policy is especially marked for countries other than Germany in the European monetary union.

Over the last 20 years, monetary policy in the United Kingdom has also moved in the direction of greater independence as well as toward rule-based policymaking. After experiencing a major exchange rate crisis, the United Kingdom adopted a form of inflation targeting in October 1992. In May 1997 (and subsequently formalized by the Bank of England Act of 1998), the Bank of England gained operational independence from the government. The Bank of England is now specifically required primarily to pursue price stability and only secondarily to make sure that its policies are consistent with the growth and employment objectives of the government. The government periodically sets an inflation target, currently 2 percent, and the central bank is given broad freedom in achieving this target. As part of the inflation target, the government also sets ranges for acceptable fluctuations in inflation. If inflation moves outside its target range, the central bank is required to report on the causes for this deviation, the corrective policy action the central bank plans to take, and the time period within which inflation is expected to return to its target range.

The movement toward rule-based monetary policy is widespread. By 2002, 22 countries had adopted monetary frameworks that emphasize inflation targeting (Truman, 2003). The following countries are listed by the date in which inflation targeting was adopted (and in some cases readopted): in 1989, New Zealand; in 1990, Chile; in 1991, Canada and Israel; in 1992, the United Kingdom; in 1993, Australia, Finland, and Sweden; in 1995, Spain and Mexico; in 1997, Czech Republic and Israel (again); in 1998, Poland and Korea; in 1999, Brazil, Chile (again), and Colombia; in 2000, Thailand and South Africa; in 2001, Hungary, Iceland, and Norway; in 2002, Peru and the Philippines. These countries have all openly published their inflation targets and have described their monetary framework as one of targeting inflation. Clearly, inflation targeting is worldwide; the countries range from developed economies to emerging market economies. The number of countries adopting inflation targeting is growing over time.

The first country to adopt inflation targeting, New Zealand, has gone the furthest in setting up a rule-based regime. Before 1989, monetary policy in New Zealand was far from being rule-based. As Nicholl and Archer (1992, p. 316) describe:

New Zealand experienced double digit inflation for most of the period since the first oil shock. Cumulative inflation (on a Consumer Price Index (CPI) basis) between 1974 and 1988 (inclusive) was 480 percent. ... Throughout the period, monetary policy faced multiple and varying objectives which were seldom clearly specified, and only rarely consistent with achievement of inflation reduction.

In 1989, the government of New Zealand adopted legislation mandating that the objective of the central bank be to maintain a stable general level of prices. The government and the governor of the central bank must agree to a policy target, which specifies an acceptable range for inflation. Since the act was adopted, the inflation rate has fallen considerably and has been well below 5 percent per year over the last decade or so.

Figure 2 displays the inflation experiences for four countries—the United Kingdom, New Zealand, Canada, and Sweden—that have adopted inflation targeting. The four panels of Figure 2 show the inflation rates before and after the date of the inflation targeting regime, marked by a vertical line. The bands in the figure following the adoption of the inflation targeting regime depict ranges of inflation as specified in the regime. Although the countries did not always remain within the target range for inflation after adopting inflation targeting, inflation fell substantially in all the countries after the adoption of inflation targeting. The literature contains ongoing controversy about whether this decline was solely due to inflation targeting, but also offers substantial consensus that inflation targeting played an important role in the decline.

Even in countries that have not explicitly adopted inflation targeting, the institutional framework for the conduct of monetary policy has changed in a way consistent with modern macroeconomic theory. In the United States, for example, the central bank has been moving toward openness and targeting for the last 25 years. The Full Employment and Balanced Growth Act of 1978 (commonly referred to as the Humphrey-Hawkins Full Employment Act) required the Federal Reserve Board of Governors to report periodically to Congress on the planned course of monetary policy. Furthermore, the Federal Reserve Board has changed some policies in ways that increase transparency. For example, the minutes of Federal Open Market Committee meetings are now released substantially sooner than they used to be, and the FOMC’s decisions regarding its interest rate target are now released immediately after the meeting. A large academic literature motivated by Taylor (1993) argues that the Fed has effectively moved toward a rule-based regime and is therefore well placed to solve the time inconsistency problem.

Although the changes in the practice of monetary policy documented above cannot be definitively linked to the recent theoretical developments in macroeconomics, the most straightforward explanation for these changes is that they are due to the identification of the time inconsistency problem by macroeconomic theorists.

Extending the Bounds of Macroeconomics

Macroeconomic theorists have long focused on frictions in the labor market as a source and propagation mechanism for business cycles. Over the last few years, a significant focus of macroeconomic research has been the effects of government policies on the secular trends of labor markets. The distinguishing feature of this research is that it is based on quantitative general equilibrium models along the lines inspired by Kydland and Prescott (1982). Although the work in this area has not yet progressed to definitive policy prescriptions, it is beginning to offer powerful insights into what may have caused some problems in labor markets and what sorts of policy changes might be part of the solutions.

An issue that has captured much scientific and popular attention has been the recent stubbornly high rates of unemployment in Europe. Figure 3 shows the behavior of average unemployment rates in Europe and the United States from 1956 to 2003. Until the late 1970s, unemployment was roughly two percentage points lower in Europe than in the United States. Since about 1980, European unemployment increased significantly while U.S. unemployment decreased. By 2003, unemployment averaged more than 9 percent in Europe, compared with only about 5 percent in the United States.

Another way to examine labor markets is to focus on employment rates, measured as the annual average hours worked per adult of working age. Figure 4 displays the behavior of this measure of employment rates in Europe and the United States from 1956 to 2003. According to this figure, employment steadily declined over the entire period in Europe, whereas in the United States, it was roughly stable until the 1980s and then sharply increased.