In an interview, Paul Volcker, chairman of the Federal Reserve's Board of Governors from 1979 to 1987, was asked about the Fed's use of monetary policy to reduce the rate of inflation. Volcker replied:
The Federal Reserve had been attempting to deal with ... inflation for some time. ... By the time I became chairman ... we adopted an approach of ... saying, We'll take the emphasis off of interest rates and put the emphasis on the growth in the money supply, which is at the root cause of inflation ... we will stop the money supply from increasing as rapidly as it was ... and interest rates went up a lot. ... We said ... we'll take whatever consequences that means for the interest rate because that will enable us to get inflation under control.
Explain why the Fed, while Paul Volcker was chairman, did not target both the growth of the money supply and interest rates.