These repayments are almost offsetting a surge of lending at the fringes to first-home buyers and returning rental-property investors. Total household debt rose just 1.8 per cent in the year to the end of June to $187.9 billion, which is less than growth in household income.
That means households are beginning to de-leverage, albeit slowly. Also, those who have already paid off their mortgages are saving more. Household deposits rose 8.8 per cent to $108.9 billion in the year to the end of June.
To put those two forces together, household deposits rose $16.8 billion in the past two years and household borrowing rose $5.2 billion. That means $11.6 billion less was spent in places where it could be recycled in the form of wages, profits and taxes.
This was one reason voters didn't mind voting for austerity. If voters were denying themselves spending, so should the Government.
Luckily for the economy, the Government had spent an extra $7.2 billion in the past two years. That offset most of the $11.6 billion less being spent by households.
But now we have a problem. The Government is carrying through on its "zero" budget over the next couple of years. There will be no offset to the restrictions in spending by households as they save more. Businesses and exporters are expected to pick up the slack by spending and earning more.
The trouble is they're not, in part because the rest of the world is also spending less and saving more.
This is the paradox of thrift. It makes sense for one household to save but when every household, the Government and businesses do it in tandem, you get a recession. When every country does it, the whole world has a big, big problem.
Globally, almost all policymakers are fixated on austerity and debt-reduction. They're all assuming someone else will pick up the slack and spend money on whatever they're producing. The Chinese mostly assume it will be the Europeans and Americans.
The Americans and Europeans are hoping it will be the Chinese. New Zealand hopes it will be the Australians and the Chinese. It's as if a bunch of cricketing outfielders are all looking at each other shouting, "Yours!", only for the ball to drop between them.
At some point policymakers will have to pull out of this paradox of thrift, including Key.