Lack of fresh data still costing
The 2011 census was the most expensive survey New Zealand never had, costing $65 million.
It was meant to occur on March 8, 2011, but was cancelled after the Canterbury earthquake in February that year.
Figures from Statistics New Zealand show that, despite almost no data being collected, the cancelled countrywide stocktake still cost $65m.
This included paying more than 7000 contractors - who had already delivered census forms to about 500,000 houses - in full.
Census 2013 general manager Carol Slappendel said the 2011 census was cancelled after huge amounts of money had already been spent on training, education and preparation.
"We had 140 field officers, we had printed all of the forms, we were fully operational," Slappendel said.
"It was a very difficult decision, particularly for the staff, but it was the right decision."
But having no fresh census data may be costing New Zealand considerably more, as government agencies continued to allocate funding based on ageing and potentially wrong data from 2006.
Census figures were used to determine the decile system for schools, which directly impacted on how much funding was allocated, Slappendel said.
"The decile rates haven't been updated for seven years. Schools may not be getting the resources they need."
The census is also used to determine Ministry of Health funding for district health boards and set priorities for road repairs or improvement.
Slappendel said the longer New Zealand went without a census the bigger the potential for wasting public funds.
"Billions in funding allocated is based on census data. But when you get to year five, six, seven out, the variability in the reliability starts to increase."
This is a particular problem in New Zealand, which has one of the most mobile populations in the world. Between the 2001 and 2006 census, more than half of all New Zealanders had moved within the country.
"As the population changes, areas grow and others get smaller, it is important we are using our scarce resources in areas of need."
Statistics New Zealand is currently surveying agencies that use census data to gauge just how big an impact the lack of fresh information is having.
As of yet, there is no clear way to quantify the impact but Slappendel said post-quake Christchurch was particularly hungry for new figures.
However, government agencies have played down the importance of the census, saying there are other sources of data to work off.
Ministry of Education group manager David Lambie said a lot of funding was allocated based on internal figures and birth projections.
"Most of this data does not derive from the census," he said.
The next census is on March 5, with a budgeted cost of $90m.
Slappendel said that because the census would use a lot of the groundwork and equipment from the abandoned 2011 census the final cost was expected to be closer to $72m.