In New Zealand, in all age groups under 20, and in key working age groups, historically there have been more men than women. However, census data indicate that the number of New Zealand women residents relative to men in the broad 20-49 age group has been increasing since the 1980s.
Given that birth ratios for New Zealand residents favour boys in common with international experience, the imbalance of women over men in the 20-49 age group has to come from four possible sources: 1) differential mortality, 2) more New Zealand born men leaving New Zealand, 3) a higher number of female immigrants, or 4) that statistical collections are undercounting men, and this undercounting has become progressively greater over the past 20 years.
The study indicated that differences in mortality between males and females at ages between 20 and 49 years makes a small contribution to the numerical imbalance between the sexes, that over recent decades migration both in and out of New Zealand plays an important but quite complex role, and that undercount may be more important that previously considered. This exploratory study cannot determine the relative weight of each factor. To achieve this would require more detailed modelling work.
In theory, a shortage of males in key couple forming age groups may lead to more women not having a (male) partner and relatively fewer unpartnered men, which may reduce fertility, and may lead to an increase in female employment. New Zealand data show that over the long term more women are either living on their own or are sole parents, female employment has increased and fertility has declined. However, this trend is evident in all countries, regardless of the prevailing sex ratios.
While unlikely to be a key driver of behaviour, the recent changes in sex ratios, in absolute terms but more importantly educationally, are likely to support some continued growth in female employment and women living on their own. They are also likely to make it more difficult to support fertility rates at, or above, replacement rates. In addition, given the greater propensity for women to marry ‘down’ educationally, women’s increased bargaining power within couple households over issues such as childcare may mean that negotiating work-life arrangements with their employers becomes more important for men in the future.
This exploratory study is funded by the Department of Labour's Future of Work Contestable Fund and has three main objectives. These are:
- Why, since the early 1980s, has there been an increasing number of women, particularly well-educated women, relative to men within prime-working age groups in New Zealand?
- Are differences in opportunities in global labour markets influencing the gender and educational composition of migration flows in and out of New Zealand, or are there other reasons for the imbalance?
- What, if any, are the labour market implications of an imbalance between women and men.
A fourth subsidiary objective is to explore the possible implications of changes in sex ratios on couple formation and on fertility. Underlying this objective is an assumption that changes in household type and in fertility may ultimately have an effect on labour markets