Distinctive features of age-specific fertility profiles in the English-speaking world: common patterns in Australia, Canada, New Zealand and the United States, 1970-98

The paper seeks to identify common features in the fertility patterns of the English-speaking world and provide a model basis for comparison of fertility between countries and over time. Attention is focused on the heterogeneity within the fertility patterns of Australia, Canada, New Zealand, and the United States, similar to that reported earlier for the UK and the Irish Republic. The recent age-specific fertility patterns of these countries display a marked 'bulge' in fertility of women under age 25. A mixture model with two-component Hadwiger functions provides a suitable fit. The heterogeneity thus suggested is related to the proportion of births outside marriage. Additionally, there is some evidence that, in the United States, and lesser extent in New Zealand, this heterogeneity in fertility patterns may be explained by ethnic difference in the timing and number of births.