Why were New Zealand levels of life-expectation so high at the dawn of the twentieth century?

Abstract

With population ageing becoming an issue of major importance for societies in the developed countries, in both the scientific and policy communities there is widespread interest in the determinants of these structural changes. The focus has been on declines in fertility, arguably the major causal factor, but increasingly analyses are turning to the other major determinant, improving survivorship. This paper relates to this aspect of ageing but not to fertility per se