A banking expert believes there's enough competition as it is, between the country's eight largest banks.

The Financial Markets Authority's found all but one lifted floating mortgage rates 25 basis points after the OCR rose by the same amount this month.

The average bank lifted its savings rates by only 17 basis points. 

Massey University's Claire Matthews told Mike Hosking that there's always the argument competition's not working the way it should - but she thinks otherwise.

She believes banks are looking very closely at what each other are doing, and acting in response to that.

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