Claims the government's ban on future oil and gas exploration will cost the country up t0 $30 billion are being described as unsurprising.

The Institute of Economic Research has released its findings on research commissioned by Petroleum and Production Exploration New Zealand.

It says the Government's ban could cost the economy up to $30 by 2050.

NZIER chief executive Laurence Kubiak told Kate Hawkesby the actual result will be driven by policy decisions over the next 30 years.

"I don't think it would come as a surprise to anyone that banning exploration would come at a cost."