No one can say with certainty what's behind the halving of New Zealand's teen birth rate in eight years.
As we reported yesterday, new Statistics New Zealand data shows the teen birth rate has dropped each year since 2008 when it was 33 births per 1000 women aged 15 to 19.
Last year the rate dropped to 16 births per 1000 women in that age group.
Family First NZ national director Bob McCoskrie thinks he knows the reason - that the message to abstain from or postpone sexual involvement is getting through to teens.
He cited an Auckland University survey which found fewer students reported having sex in 2012 than in 2001 and 2007.