Census data might not be out until August 2019

Stuff reports:

The continued threat of incomplete data has Statistics New Zealand again pushing the deadline for Census 2018 results.
Documents released under the Official Information Act show the department is planning for an August 2019 deadline, and continues to stare down a high risk it may not produce viable results.
A low turnout during Census 2018 has caused considerable pain for Stats NZ, which last week announced it would not make the third deadline it set – July 2019 – and promised to announce a release date in April.
Experts are concerned the repeatedly slipping deadlines will have a detrimental impact on planning and funding decisions to come in 2019, and the data might already be “stale”. 

The data will be somewhat stale by then and we are told what they do release my not even be viable.

I can’t work out why Stats NZ didn’t just hire a thousand students and get them to door knock the addresses with low or nil response rates. They’ll know who they are from existing data, NZ Post, Electoral roll etc.