Competition between the mortgage lenders also acted to keep fixed rates low as bank margins were reduced to historically low levels. "The Reserve Bank kept pushing up the Official Cash Rate to slow demand. The effective mortgage rate, the main transmission mechanism for monetary policy in New Zealand, rose, but to only half the extent of the Official Cash Rate increase.
In 1966, the Federal Open Market Committee (FOMC) began to add a proviso to its policy directives that bank credit growth should not deviate significantly from projections; a similar proviso about money growth was added in 1970.