First, monetary policy, in the long run, principally affects nominal variables such as nominal income, the price level, and the rate of inflation, but has lesser effects on real variables – such as the level of employment or the level or growth rate of output.
I expect all central bankers would agree that an environment of price stability offers the best contribution that monetary policy can make to the level and growth of output because it eliminates distortions to resource allocation and disincentives to saving and investment associated with high and variable inflation rates.