The Reserve Bank is independent – if you are a politician you don’t say what you think they should do, as any opinion can be construed as pressure on the Governor. No politician should do it – especially not a potential prime minister in waiting!
Ultimately, the Reserve Bank is a machine that turns interest rates into inflation outcomes – but it can only perform this process (effectively) as long as people believe it is “credible”. If the government leaves the machine alone it can function, and it can keep inflation low without damaging growth. If politicians start stuffing with the machine by questioning it, its credibility stops working and we end up with worse outcomes.
It is a magical machine – politicians should not mess with it. So please, John Key, do not say what you think should happen with interest rates. If you become prime minister you can mess with aggregate demand through fiscal policy – there is no need to try to jump into monetary policy as well.
Winston Peters can say things about monetary policy as no-one listens to him, but both John Key and Micheal Cullen are individuals that people do listen to – as a result, please pick your words around monetary policy carefully, this is not the United States after all.
Update: On that note, here is Winston Peters talking rubbish. Truly, this sort of rubbish makes me certain that he cares more about getting into parliament than he does about the people he is supposed to serve.