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Some economists argue that there are some benefits to inflation, at least if the inflation is only moderate. These arguments are worth noting, in part because they are associated with some prominent policymakers of the 1990s.

In particular, long before he was U.S. Secretary Treasury, Lawrence Summers (1991) wrote, "the optimal inflation rate is surely positive, perhaps as high or 2 or 3 percent." Although Summers has never had direct control over monetary policy, Fed policymakers are well aware of the views of prominent Treasury officials. Moreover, nations that have adopted a policy of inflation targeting (which were numerous during the 1990s) have typically chosen a positive number, rather than zero, for their target. In this environment, claims that the Fed is aiming for "price stability" should perhaps not be taken too literally. The 3-percent inflation experienced during the 1990s may be close to the target policymakers had in mind.

One argument for a target rate of inflation greater than zero is that it permits real interest rates (that is, interest rates corrected for inflation) to become negative. Because individuals can always hold cash rather than bonds, it is impossible for nominal interest rates to fall below zero. Under zero inflation, real interest rates also can never become negative. But if inflation is, say, 3 percent, then the central bank can lower the nominal rate toward zero and send the real interest toward negative 3 percent. The ability to produce negative real interest rates gives the central bank more latitude to stimulate the economy in a recession.

Some economists point to Japan in the 1990s as an example of why some inflation is desirable. With inflation at about zero and nominal interest rates at zero, the Bank of Japan appears to have had little room to stimulate the economy. Japan is said to have been stuck in a "liquidity trap" when monetary policy loses its effectiveness. If Japan had inherited a tradition of more inflation, the argument goes, then when the Bank lowered nominal rates to zero, real rates would have become negative. A negative real rate would have stimulated spending and helped pull the economy out of its lingering recession.

This line of reasoning is controversial. Some economists dispute the claim that Japan was stuck in a liquidity trap. They argue that more aggressive Japanese monetary expansion would have lowered real rates by raising inflation expectations or that it would have stimulated exports by causing the yen to depreciate in foreign exchange markets.

Nonetheless, this argument for positive inflation may well have influenced U.S. monetary policy during the 1990s. (…) Moreover, the Japanese experience in the aftermath of its stock market and real estate bubble was a warning flag of what might happen in the United States if the booming stock market were ever to suffer a similar collapse. The 3-percent inflation rate gave Fed policymakers the option to stimulate spending with negative real interest rates, if the need should ever have arisen.

A second argument for moderate inflation starts with the observation that cuts in nominal wages are rare. For some reason, firms are reluctant to cut their workers' nominal wages, and workers are reluctant to accept such cuts. A 2-percent wage cut in a zero-inflation world is, in real terms, the same as a 3-percent raise with 5-percent inflation, but workers do not always see it that way. The 2-percent wage cut may seem like an insult, whereas the 3-percent raise is, after all, still a raise. Empirical studies confirm that nominal wages rarely fall.

This fact suggests that inflation may make labor markets work better. Here's the argument. The supply and demand for different kinds of labor is always changing. Sometimes an increase in supply or decrease in demand leads to a fall in the equilibrium real wage for a group of workers. If nominal wages can't be cut, then the only way to cut real wages is to allow inflation to do the job. Without inflation, the real wage will be stuck above the equilibrium level, resulting in higher unemployment.

For this reason, some economists argue that inflation "greases the wheels" of labor markets. Only a little inflation is needed : An inflation rate of 2 percent lets real wages fall by 2 percent per year, or 20 percent per decade, without cuts in nominal wages. Such automatic reductions in real wages are impossible with zero inflation. There is reason to suspect that this argument for positive inflation also influenced U.S. monetary policy in the 1990s. Once again, Lawrence Summers endorsed this view at the beginning of the decade when he proposed a target rate of inflation of 2 to 3 percent. Subsequently, the case was advanced by a Brookings research team that included George Akerlof, husband to Janet Yellen, a Clinton appointee to the Federal Reserve. These facts suggest that some U.S. monetary policymakers during the 1990s may have been skeptical about the desirability of pushing inflation all the way down to zero. The 3-percent inflation realized during this period may have been exactly what they were aiming for.