New Zealand could become predator free, for a cost of just over $9 billion.

A group of Auckland University Biological Scientists and Statisticians has published a paper outlining how, in the international journal BioScience.

University of Auckland Senior Lecturer Dr James Russell says it's a change in mindset.

"This is the first time we've combined all these different compartments - how much we currently spend, how much pest control there currently is, how much it might cost - and put it all together and say this is actually economically viable."