I disagree that rates should be hiked early and hard.

As you yourself have noted, total labour underutilization (in the form of underemployment) is rather worse than official unemployment figures depict.

Large numbers of full time jobs have been replaced by part-time employment and with Australians so heavily mortgaged, low interest rates are the only thing between them and foreclosure.

Of course, it is also a neo-liberal article of faith that deficit spending necessarily crowds out private sector investment and drives up borrowing costs when the fact is that the standard teachings of the textbooks stay the same while the world moves on and new realities overtake the old models - which continue to be taught as Darwinian fact regardless.

I pointed out to The Australian's economics editior Micheal Sutchbury that for well over six months he and his ilk have been hollering that all the government spending would crowd out private investment and then just the other day he prints an article that purports to show that business investment is taking off in this country - while a good sized deficit is being run. For some reason he has stopped printing my comments.

Historically, Australia has had interest rates that have been among the highest in the world, certainly among the developed countries. Why is this? Why do we need to raise rates from their so-called 'emergency' low levels? Most borrowers are currently paying 6% or so on their housing loans; where are the economic justifications to support raising current rates when many competitor nations have their citizens paying much lower rates?

It seems to me that the government has a binary mind, it is either
on or off. A fire hose or nothing.
Politicians do not understand control engineering.
There are three terms, Proportional, Integral and Derivitave.
A three term controller stops the system going into oscillation or
making changes that are too soon or too big or too late.

The maths that are used can also be applied to the economy.
I presume that economists use similar systems, or do they ?

The government does not seem to understand that to get the system back
to the set point, ie the point where no change is needed cannot be
done by turning one of the inputs, money, on and off at maximum.

It just cannot be done and this is what Malcolm Turnbull has been
saying.
I don't think he understands why, but he just seems to sense it.
I think the senate is now sensing it already it is just that
politicians do not understand the mechanism.