Population growth in New Zealand over the last couple of cycles has tended to fluctuate in a way that does not match the apparent movements in neutral rates, and the recent fall in population growth is small by the standards of past movements. At the same time, the longer-lasting downtrend in world population growth raises interesting questions about the implications for neutral rates abroad.
Figure 6 Population growth (5 year moving average)  Source: World Bank  d)  Preferences for savings  As I have mentioned, if people decide to save more and consume less a lower interest rate would be required to boost the pace of activity and inflation and reconcile saving and investment plans.