Editorial: Census data so far has little bearing on city plans

New Zealand's population growth had halved since the last Census. Photo / APN

According to a phrase usually attributed to Mark Twain, there are "lies, damned lies and statistics". It was his way of saying we should be wary of figures that are used to boost weak arguments. Perhaps, most particularly, we should be cautious about statistics given so dogmatically there is no apparent room for debate. Pronouncements like, for example, that of Statistics Minister Maurice Williamson, who declared the first Census data in seven years contained a surprise "bigger than Ben Hur".

The finding that so enraptured the minister was that New Zealand's population growth had halved since the last Census. The population had increased by 31,000 a year, or 0.75 per cent, over the past seven years, compared to 58,000 a year in the previous 2001-2006 period. This, trumpeted Mr Williamson, should prompt a revision of Auckland's infrastructure plans, such as an increase in high-rise apartments and the construction of an inner-city rail loop.

The growth rate is, indeed, surprisingly slow. But what that means for Auckland must be subject to a couple of important caveats. First, the data so far released - annoyingly, the Census findings are being drip-fed - does not reveal the extent of Auckland's long-term growth. This, as the Auckland Council's chief planning officer, Roger Blakeley, noted, has historically been much more rapid than for other regions. This is not expected to change. Auckland has and will receive more migrants, and has a more youthful population than the rest of the country and, therefore, a higher fertility rate.

A second proviso arises from the fact that the number of people leaving the country reached record highs during the past seven years. Already, this has started to decline as the Australian economy encounters headwinds. It is highly unlikely the emigration rate will continue to match that of the past seven years.

This doesn't mean no notice should be taken of the Census data. The council's planning for the next 30 years, as outlined in its Unitary Plan, is based on the prediction that the number of Auckland residents will grow by one million, or 2.2 per cent a year. The plan is hugely important because of the impact on Auckland of constraining most of the city's growth within existing urban limits and encouraging higher-density development close to public transport. The prospect of intensified housing is by no means universally applauded, and the Census findings for Auckland, when they are finally released, warrant close attention in terms of the population assumption.

Contrary to Mr Williamson's view, however, the same cannot be said of the inner-city rail loop. Its construction is not predicated on population growth. Rather, it is about the shape of Auckland, the number of people who live and work in the central city, and creating an essential and efficient public transport artery. Debate over it should revolve primarily around issues such as potential patronage and funding options, not projected population.

This distinction has never been appreciated by the Government. While endorsing the rail loop in principle in June, it scheduled it for 2020, five years later than the council wants. The Government said a start could be made earlier if Auckland's population growth led to increased inner-city employment. It needs to understand that a start on the project should not depend on such a link.

Clearly, much of Mr Williamson's gusto doesn't withstand too much scrutiny. Nonetheless, he has ensured that attention will be paid to Census regional growth findings when they are released next week. If there are genuine reasons to question the assumptions underpinning the Unitary Plan, they will be found there.