Crucial government statistics on international tourist spending have not been fit for purpose for some time, a tourism industry body says.
The Ministry of Business, Innovation and Employment (MBIE) asked Stats NZ to review its International Visitor Survey (IVS) after long-standing criticisms from the tourism sector about the the way it is done, and the reliability of its results.
Tourism Industry Aotearoa chief executive Chris Roberts said it was a really important survey, and the review showed there were significant shortcomings with the survey and an "alarming lack of oversight" from officials.
He said in 2013 the survey changed from face-to-face interviews with travellers at airports to them instead being asked to fill in the survey later online.
"Since that change in the way the survey's been conducted, this review has identified that the ... survey has never actually been implemented as it was designed," Mr Roberts said.
"And that means that there's been sampling and data processing problems building up.
"And it's all really quite shoddy for what is an incrediblely important survey, and a very important contributor to our national account statistics."
An example of another problem was that the data on Chinese visitors was not reliable, which was crucial for such a fast growing market, Mr Roberts said.
There was difficulty getting people from China to fill in the survey, so they stopped chasing them and instead over-collected from Australians, he said.
"That's just something that has to be fixed," he said.
Stats NZ general manager Dean Rutherford said the survey needed "a tune-up but not a complete overhaul".
"Stats NZ acknowledges earlier tourism industry concerns about the volatility in past IVS results, which showed visitor spend dropping while visitor arrivals rose. Those concerns led to this review."
There were a few areas where changes needed to be made to bring the operation into line with the intended design, he said.
"The good news there though is that many of those changes are actually relatively straightforward to make."
Stats NZ would be working MBIE to instigate 10 recommendations to improve some technical aspects and governance of the survey, and this would also help with getting accurate figures on Chinese visitors, he said.
"The survey is designed to be able to ... [measure] total expenditure in New Zealand by foreign visitors, and there's nothing that we've seen in our review that's suggests it's not fit for purpose for that."
The survey of 8900 people would continue to be done online because there was "no compelling evidence" going back to face-to-face interviews would make it more reliable, Mr Rutherford said.
MBIE said it was taking Stats NZ's recommendations seriously, and was already working to address some of the issues raised.