Parity structure of low-fertility populations

Serguey Ivanov, United Nations

The paper is based on “Partnership and Reproductive Behaviour in Low-Fertility Countries” (United Nations 2004) and uses cohort and period measures of parity distributions as they vary across countries and time. Parity dynamics vary among low-fertility populations. Prevalence of childlessness, popularity of two-child families and propensity to achieve high fertility preferences (three children or more) acted together but often in different and evolving combinations in shaping levels and trends of cohort and period fertility during the 20th century. In some countries increasing childlessness and/or spreading of one-child family models played the major role in fertility trends below replacement. In other countries shrinking of third and higher-order births was a decisive factor in fertility decline. Currently parity distributions vary more than average cohort fertility because, inter alia, widespread childlessness is sometimes balanced by high proportions of women with three children or more. Concurrently, low prevalence of childlessness does not necessarily mean higher fertility.