The Pseudo-Psychology Behind Monetary Policy
In his various writings, the champion of the monetarist school, Milton Friedman, argued that there is a variable time lag between changes in money supply and its effect on real output and prices. Friedman holds that in the short run changes in money supply will be followed by changes in real output.
However, in the long-run changes in money will only have an effect on prices. All this means that changes in money with respect to real economic activity tend to be neutral in the long-run and non-neutral in the short-run. Thus according to Friedman,