Among central bankers, the maintenance of low and stable inflation is widely regarded as a sign of overall good economic management. Economists today agree that economic growth, in and of itself, does not cause inflation—so long as the central bank adopts appropriate policy in a timely way to limit inflation.

Former Federal Reserve Chairman William McChesney Martin quipped that it was his job to remove the punch bowl before the party got out of hand—but, of course, not to prevent the party in the first place. But, what are the costs of failing to do so? That is, how strong is the evidence that inflation more rapid than price stability significantly reduces economic growth?

For policymakers, the measure of their success is price stability, often defined as an inflation rate that is sufficiently low, stable and predictable so as not to be a factor in private decisions. Policymakers usually equate low inflation to annual increases of 1 to 2 percent in a broad index of consumer prices, excluding food and energy, a rate that the current Fed chairman, Ben Bernanke, once dubbed the "optimal long-run inflation rate." Such a rate, in part, acknowledges imperfections in adjustments to the prices of existing goods for quality improvements and to the prices of new goods not previously included in the price index. The rate also reflects, in part, a cushion against the risk that an adverse economic shock might corner policymakers against the zero lower bound on nominal interest rates.

The idea that price stability is a necessary condition for maximum sustained economic growth is a common theme among Federal Reserve officials. At the 2005 Federal Reserve Bank of Kansas City policy conference honoring his service and retirement, then-Chairman Alan Greenspan said, "I presume maximum sustainable economic growth will continue to be our goal, with price stability pursued as a necessary condition to promote that goal." Bernanke has expressed similar views. At an October 2004 Federal Reserve Bank of St. Louis conference, Bernanke, then a Federal Reserve governor, said, "The low-inflation era of the past two decades has seen not only significant improvements in economic growth and productivity but also a marked reduction in economic volatility, both in the United States and abroad." He went on to say, "There is evidence for the view that improved control of inflation has contributed in important measure to this welcome change in the economy."

How Might Sustained Inflation Reduce Output Growth?

There are a number of mechanisms through which sustained inflation at a rate higher than Bernanke's optimal long-run inflation rate can hamper economic growth. One is the monetary cost of inflation, which arises because inflation, by eroding the purchasing power of money, causes households and firms to incur additional costs to manage their money balances. Many authors have argued that such costs are small. Michael Dotsey and Peter Ireland, however, construct an example where the combined impact of a number of costs, each individually small, is large.1 Other analysts have argued that inflation's costs appear small only because traditional models are not rich enough to capture many of the costs of inflation. Otmar Issing, a member of the executive board of the European Central Bank and a former officer at the German central bank (the Bundesbank), has argued that economists' estimates of the costs of sustained inflation are fragile because they depend on the specifications of individual models.2 Inflation, he argues as an example, confuses households and firms as they seek to disentangle changes in relative prices from movements in the overall price level and to distinguish temporary from permanent price changes—but models seldom include such costs.

Two additional channels through which inflation is costly are the tax system and uncertainty regarding future interest rates. Former Federal Reserve Bank of St. Louis President Thomas Melzer aptly summarized the problem: "Higher inflation ... interacts with our nominally based tax system, especially with taxes on capital, to create large distortions. And higher inflation causes people and businesses to waste resources in trying to economize on their money holdings. A good deal of research suggests that these costs are substantial. To make matters worse, the risk of higher inflation creates uncertainty, which also exacts costs, including an inflation risk premium in interest rates."

A number of empirical studies have sought to measure the interactions between inflation and the nominal nature of the U.S. tax system. Most find the costs are large. Authors James Bullard and Steven Russell, for example, suggest approximately a 1 percent output loss for each 1 percent increase in inflation above price stability.3 Martin Feldstein has examined how interactions between inflation and the tax system discourage saving while increasing housing demand.4

Our tax system imposes taxes on nominal earnings net of nominal deductions, rather than on real earnings net of real deductions. Similarly, nominal interest payments are tax deductible by businesses and taxable income by investors without adjustment for the effects of inflation. In these and other aspects, our tax system violates the quantity theory's requirements necessary for real output to be unaffected by the rate of inflation, that is, for money to be neutral. (See below on the neutrality of money.)

Feldstein calculates that a one-time reduction in the inflation rate from 2 percentage points above price stability to price stability would cause the level of gross domestic product (GDP) to increase by approximately 1 percent. He concludes that the present value of the costs over time from the interaction of inflation and the nominal tax system equals approximately 30 percent of current-period GDP.

Darrel Cohen, Kevin Hassett and R. Glenn Hubbard have examined the interaction of inflation and taxes by examining the effect of inflation on businesses' cost of capital.5 They argue that inflation, even at very low levels, can significantly increase the cost of capital. A decrease in expected future inflation will reduce expected future user costs for capital and stimulate investment spending. Surprisingly, their estimates suggest that this effect is most important at low inflation rates, that is, at the margin between inflation consistent with price stability and moderately higher inflation.

At high inflation rates, the tax benefit to the firm of depreciating capital equipment already has been greatly reduced, such that small changes in the inflation rate matter little. At moderately low inflation rates, however, the tax value of depreciation is substantial—and a small further reduction in inflation can significantly change the firm's cost of capital. Moreover, they find that this effect is larger for modern capital goods with rapid depreciation rates and shorter usable lifetimes, such as information and communications equipment.

Quantitative impacts from their model are substantial. In one version of their model, if the annual inflation rate were to be reduced from 4 percent to zero, the user cost of capital would decline by 8 percent. This decrease would increase business fixed investment by approximately 6.5 percent. In addition, output per worker would increase by approximately 2.2 percent, and consumption per worker by about 1.3 percent. Hence, the lower sustained inflation rate increases both aggregate output and productivity.

The studies above focus on distortions caused by higher inflation in the United States. Do empirical studies find similar effects in other countries that may have very different financial structures, including different tax systems? In general, no. Two studies, one written by Robert Barro and the other by Michael Bruno and William Easterly, report no significant difference in growth rates across countries with annual inflation rates as rapid as 40 percent.6 Similarly, a recent study by the International Monetary Fund that examined the impact of inflation on economic growth in emerging-market economies (EME) reached a similar conclusion.7

The IMF study compares inflation and economic growth in 13 EMEs that adopted inflation targeting (IT) between 1998 and 2002 to a control group of 29 countries that did not. Countries that adopted IT subsequently experienced both a lower rate of inflation and reduced inflation volatility. The report suggests, however, that IT countries experienced only a modest boost in economic growth relative to the control group. Figure 2 compares the experience of the IT countries (upper panel) that had annual inflation rates below 40 percent when they adopted IT (9 of the 13), and the control-group countries (lower panel) that had annual inflation rates below 40 percent at the end of 1999 (19 of the 29).8 For the IT countries, 6 of 9 experienced more rapid growth after adopting IT; the median annual growth rate increased to 3.5 percent from 2.8 percent. For the control-group countries, 8 of 19 experienced more rapid growth; the median annual growth rate increased to 4.5 percent from 4.2 percent.

Is Higher Inflation Costless?

The empirical studies reviewed above suggest that little or no increase in economic output tends to follow reductions in inflation from a moderate, sustained pace to a slower pace near the rate defined as price stability. Does this imply that higher inflation is costless? No, not at all. First, as mentioned earlier, empirical studies often omit some of the more subtle and difficult-to-measure impacts of inflation. In the United States, tax-related distortions are relatively straightforward to measure while other distortions are less so. Other nations' tax systems may react quite differently to higher inflation, and, ironically, extensive tax evasion tends to blunt the interaction of a nominal tax system with inflation. Second, maintaining low, stable inflation tends to anchor the public's inflationary expectations. When inflation expectations are well-anchored, policymakers gain additional latitude to adopt aggressive policies when needed to offset large shocks to the economy without the risk of destabilizing the financial system. Finally, a policy of maintaining low, stable inflation enhances both the government's credibility and the confidence of household and businesses in the economy, tending to boost investment and growth. This "insurance" aspect also often is omitted from models.

By itself, low and stable inflation cannot cause more rapid economic growth. An essential additional aspect is an institutional structure consistent with maintaining low, stable inflation. For most countries, fiscal discipline is the key. In their recent survey of inflation, Stanley Fischer, Ratna Sahay and Carlos Vegh note that Milton Friedman's dictum—inflation always and everywhere is a monetary phenomenon—while true, is only the "beginning of wisdom."9 Unsustainable fiscal policies—that is, the need of the government to borrow large sums—almost always is the fuel for increased sustained inflation. Excessive government deficits generate pressure on the central bank to create more money so as to provide to purchasers the wherewithal to buy increasing government debt. If the central bank refuses to do so—perhaps because of an inflation target—a fiscal and foreign-exchange crisis is likely to follow; examples include Mexico, Argentina, Turkey, Brazil, Thailand, South Korea, Indonesia and Russia. Absent public confidence in fiscal discipline, the adoption of inflation targeting (and subsequent lower inflation) should not be expected to increase growth. Despite lower current inflation, the costs associated with the older, more rapid inflation will continue until confidence in long-term fiscal responsibility is widespread.

The Answer Is Uncertain—or Is It Faith?

Among economists, the benefit of sustained low inflation as a precursor to maximum long-run economic growth is taken as an article of faith. Certainly, inflation can be costly, and creating lists of the ways in which inflation-related distortions can reduce growth is straightforward. Measuring the distortions has proved far more difficult, however; estimates of the costs of more rapid inflation remain highly uncertain. Despite the uncertainty, central bankers almost uniformly agree that sustained low inflation—at a rate no greater than that defined as price stability plus a small cushion to avoid the zero lower bound on nominal interest rates—is a prerequisite to sustaining the public's confidence in policymakers and, hence, to achieving maximum long-run economic growth.

Endnotes

1. See Dotsey and Ireland (1996). [back to text]
2. See Issing (2004). [back to text]
3. See Bullard and Russell (2004). [back to text]
4. See Feldstein (1997 and 1999). [back to text]
5. See Cohen, Hassett and Hubbard (1999). [back to text]
6. See Barro (1996); Bruno and Easterly (1996). [back to text]
7. See International Monetary Fund (2005). [back to text]
8. These countries correspond to those shown in Figure 4.2, p. 169, of International Monetary Fund (2005). [back to text]
9. See Fischer, Sahay and Vegh (2002). [back to text]
10. McCallum (2004) provides a clear discussion. [back to text]

References

Barro, Robert. "Inflation and Growth." Federal Reserve Bank of St. Louis Review, May/June 1996, pp. 153-69.

___"What Have We Learned Since October 1979?" Federal Reserve Bank of St. Louis Review, March/April 2005, Part 2, pp. 277-82.

Bruno, Michael; and Easterly, William. "Inflation and Growth: In Search of a Stable Relationship." Federal Reserve Bank of St. Louis Review, May/June 1996, pp. 139-46.

Bullard, James B.; and Russell, Steven. "How Costly Is Sustained Low Inflation for the U.S. Economy?" Federal Reserve Bank of St. Louis Review, May/June 2004, pp. 35-67.

Cohen, Darrel; Hassett, Kevin A.; and Hubbard, R. Glenn. "Inflation and the User Cost of Capital: Does Inflation Still Matter?" in Martin Feldstein, ed., The Costs and Benefits of Price Stability. University of Chicago Press for the NBER, 1999.

Dotsey, Michael; and Ireland, Peter N. "The Welfare Cost of Inflation in General Equilibrium." Journal of Monetary Economics, 1996, Vol. 37, No. 1, pp. 29-47.

Feldstein, Martin. "The Costs and Benefits of Going from Low Inflation to Price Stability," in Christina D. Romer and David H. Romer, eds. Reducing Inflation: Motivation and Strategy. University of Chicago Press, 1997, pp. 123-56.

___"Capital Income Taxes and the Benefit of Price Stability," in Martin Feldstein, ed., The Costs and Benefits of Price Stability. University of Chicago Press for the NBER, 1999.

Fischer, Stanley; Sahay, Ratna; and Vegh, Carlos A. "Modern Hyper- and High Inflations." Journal of Economic Literature, September 2002, Vol. 40, No. 3, pp. 837-80.

International Monetary Fund. World Economic Outlook, September 2005.

Issing, Otmar. "Commentary" [panel discussion on "Sustained Economic Growth and Central Banking"], Monetary and Economic Studies, Bank of Japan, Institute for Monetary and Economic Studies, Vol. 22, No. S-1, December 2004, pp. 179-201.

McCallum, Bennett T. "Long-Run Monetary Neutrality and Contemporary Policy Analysis," Monetary and Economic Studies, Bank of Japan, Institute for Monetary and Economic Studies, Vol. 22, No. S-1, December 2004, pp. 15-28.