New Zealanders are working harder and longer hours, but business productivity has barely risen since the year 2000.

Research by Grant Thornton claims a laid back business culture is to blame for New Zealand's GDP being 30 percent below the global average.

Grant Thornton partner Paul Kane says New Zealanders are hard working, but lack the business edge that's seen in other countries.

"We're just not up to speed with some of the other countries with how they do their business and our productivity is down compared to other people, for example in Australia."

Paul Kane says more Kiwi companies need to push themselves to crack overseas markets.