Census frequency

Andrea Vance at Stuff reports:

Moving to a 10-year census could make trans-Tasman comparisons tricky and create problems for historians, a populations expert says.

Statistics Minister Maurice Williamson said yesterday that the Government was considering pushing out the five-year census, after this year’s was delayed because of Canterbury’s earthquakes.

But Waikato University’s professor of population economics Jacques Poot said the shift would put data out of whack with Australia, which also collected information every five years. “New Zealand has a history that we have a census every five years and we do this in the same year as Australia.

“It has huge benefits for cross-country comparisons as well as for historians to look at long-term trends. We’ve been doing this since the late 19th century.

I think it would be regrettable to move from every five years to every ten years for the census.

A huge number of decisions are made on the data we get from the census, and in my experience the data gets stale fairly rapidly. For example if you even compare the sub-national population projections after five years with the results of the next census, you’ll see significant deviations from the projections.