The Kaikoura quake and wet spring are copping blame for unexpectedly soft economic growth in the last quarter of 2016.

But the slowdown hasn't dampened or shaken economists' upbeat outlook for the year ahead.

GDP growth came in at 0.4 per cent for the December quarter - down on a consensus forecast of 0.7. The final figure for the third quarter was also revised down to 0.8 per cent, taking annual growth for 2016 to 3.1 per cent.

A consensus of economists' forecasts had predicted a 0.7 per cent rise for the December quarter.


ASB chief economist Nick Tuffley said the Kaikoura earthquake appeared to have had a negative impact overall.

"A key source of weakness in Q4 was the transport industry, which was a major source of uncertainty for us ahead of the release," he said.

"The main complicating factor was that the transport sector was significantly disrupted by the Kaikoura earthquake, given the road, rail and port damage that occurred."

But "overall, despite this weaker result, we still see an economy supported by strong tourism demand, construction activity, robust business confidence and healthy household demand," Tuffley said.

Service industries continued to grow, increasing 0.7 per cent in the December quarter. The main drivers were business services; arts, recreation, and other services; and health and residential care.

Agriculture fell 0.6 per cent because of lower milk production. This, with falls in forestry and mining, was reflected in lower manufacturing activity and primary exports.

ANZ economists noted the wet spring weather was likely to be the key reason for contractions in both agricultural production (-0.8 per cent quarter on quarter) and manufacturing production (-1.6 per cent q/q), which together knocked 0.3 per cent off growth.

Construction, however, continued to increase, rising 1.8 per cent in the December quarter. Residential and non-residential building were both up, leading to an increase in construction trade services.

"Stats NZ did not directly mention any disruption to activity caused by the November earthquake," said Katie Hickie at Capital Economics in Sydney. "The 3.8 per cent [quarter on quarter] drop in exports was probably due to the temporary closure of some ports after the Kaikoura earthquake."

However Labour Party finance spokesman Grant Robertson questioned the quality of the growth.

GDP per head fell 0.2 per cent, following increases of 0.3 per cent in the June and September quarters.

"What this shows is that population growth, rather than improving productivity, is propping up the New Zealand economy," he said.

While the new data means the economy expanded at a much slower pace than the RBNZ's forecast of 3.5 per cent growth for 2016, it has not shifted expectations that the official cash rate will stay on hold for at least the rest of the year.