The Unavoidable Nature of Population Ageing and the Ageing-Driven End of Growth – an Update for New Zealand

Abstract

Despite overwhelming evidence to the contrary, many people still question the extent to which population ageing and the ageing-driven ending of growth will unfold more or less as projected. This is particularly so in New Zealand, where the population is still relatively youthful due to near-replacement fertility and many years of high per capita net migration gains. As elsewhere, however, the picture differs markedly at subnational level, with the populations of one-quarter of the nation’s 67 territorial authority areas (TAs) already (in 2017) having more than 20% aged 65+ years. Accompanying this trend, one-third of the nation’s TAs declined in population between 1996 and 2013, primarily because of net migration loss at young adult ages, but in the process accelerating their structural ageing. Taking a subnational approach, this paper explores the dynamics of population ageing across New Zealand’s TAs. We demonstrate that structural ageing is accelerating and that even excessively high levels of net international migration gain cannot be expected to appreciably reduce future structural ageing. We also show that over the period 2013–43 the majority of declining TAs will move from the old form of decline, caused by net migration loss exceeding natural increase, to a new form caused by the combined effects of net migration loss and natural decrease. The findings reinforce our central argument that the phenomenon of population ageing and the ageing-driven end of growth will not ‘go away’ and has urgent implications for matters such as rate-based local government infrastructure funding.