A weak New Zealand dollar continues to cushion falling commodity prices, but concerns are mounting there could be a faster than expected deceleration in global growth.
The ANZ world commodity price index fell 1.1% month on month for August, its third consecutive monthly decline, leaving the index down 0.5% year on year.
ANZ's chief economist Sharon Zollner said the shine had come off New Zealand's export prices of late.
''With the exception of the British pound, the weaker New Zealand dollar acted as a shock absorber in the month, more than offsetting lower world prices and driving the New Zealand dollar index up 0.4%, month on month,'' she said in a statement.
The kiwi is down to its lowest level against its US counterpart since February 2016, trading between US66.5c-US67c during the past fortnight.
Of the 17 commodities in the ANZ's index, seven fell, four were unchanged and six lifted.
Of the six broad categories, only forestry prices managed to squeeze out a gain, of 12.3% year on year.
''Strong Chinese demand for logs continues, but the weaker Chinese yuan and US dollar [exchange rate] appears to be impeding Chinese buyers' purchasing power,'' Mrs Zollner said.
She said given global growth appeared to be past its peak, softer world prices had been expected to some extent.
''The question is, to what extent will the Chinese yuan-US dollar hamper Chinese demand.''
There also a question mark over the global trade uncertainties and how those might yet impact global demand.
''In this environment, a faster than expected slowdown in global growth is a key risk,'' Mrs Zollner said.
She said the fortnightly global dairy trade auction prices, announced yesterday, had largely maintained last month's weakness, being down 1.4% month on month following a 6.5% fall in July.
Mrs Zollner said that overall dairy prices are down 7.9% year on year, with butter down 21.1%, cheese down 7.4% and whole milk powder down 5.5%
Beef prices fell 3% in August, to be down 9.2% against a year ago, as US supply remained strong and Mycoplasma bovis continued to boost domestic slaughter.
Aluminium prices fell 0.7% in August, but were up 1.9% on a year ago.