Why aren't the banks cutting their floating mortgage rates?

ANZ National Bank and Kiwibank have "specials" on their one-year rates at 4.55% and 4.99% respectively and the other major banks are sitting around 5.25% compared with 5.65% previously - Bank of New Zealand has chosen to offer a discounted 5.1% 18-month rate instead.

But most banks' floating rates are still around the 5.65% to 5.75% area where they've been sitting since March last year.

"It's probably because (hardly anyone) is actually fixing," says Darren Gibbs, an economist at Deutsche Bank.

"Obviously, when you've got two-thirds of your book floating, the cost of cutting floating is so much greater," Gibbs says.