According to Mansoor Khawaja from Statistics New Zealand, the recent baby boom is the result of:
young women … refusing to follow their mothers’ decisions to have few children later in life
I don’t know – I might be a bit more cynical and suggest that young women are more likely to have children now because the government is subsidising it (eg Working for Families). Of course this may turn out to be testable as:
Professor Pool and Mr Khawaja expect the recession to have a dampening effect in the next few years
While in my view, the fact that having a kid provides a guaranteed and stable income (from WFF) would actually increase the value of having kids, leading to a greater number of kids being born. Although I guess this would be counter-acted by the potential loss of the tax credit (from lower hours, or potentially from the loss of a job).