Knowing M doesn’t help much in predicting P or Q, because V is highly variable

 People’s willingness to borrow, and financial institutions’ willingness to lend, matters as well. 

The circulation of money — its velocity — depends on the actions of a vast array of financial intermediaries and their customers, of which banks are only a small part.

The Fed has targeted money supply only once, during Paul Volcker’s battle with inflation from 1979 to 1982. Even then, the motivation was primarily political: The imperative of slowing money-supply growth provided cover for Volcker to push interest rates up to previously unfathomable levels. Once inflation was defeated, the Fed quickly discarded money supply as a target.

What really matters is the level of short-term interest rates (how high for how long), their impact on financial conditions and how this influences people’s willingness to borrow and spend.

Bill Dudley Bloomberg 28 februari 2023

https://www.bloomberg.com/opinion/articles/2023-02-28/money-supply-doesn-t-explain-us-inflation