In central banking circles, it is viewed as obvious that the accumulation and destruction of reputational… — Alan S. Blinder

Monetary policy decisions tend to regress toward the mean and to be inertial—and hence biased in just the same way that adaptive expectations are biased relative to rational expectations. But errors like that, while systematic, will generally be small and will tend to shrink over time. And, in return, the system builds in natural safeguards against truly horrendous mistakes.

The new arguments for rules take an entirely different tack. They are based neither on the ignorance nor the knavery of public officials and, in fact, assume that everyone knows how the economy operates—even the government! Moreover, the government's objectives are assumed to coincide with the people's objectives, and everyone has rational expectations. Despite these seemingly ideal circumstances, modern critics argue that a central bank left with discretion will err systematically in the direction of excessive inflation. To remedy this distortion, they advocate a fixed rule.