Decomposing fertility rates – how are changing relationship patterns and increasing singlehood contributing to fertility decline?

Most children are born to cohabiting or married parents and being in a relationship is largely seen as a pre-requisite to childbearing. As such, the overall fertility rate of a country is influenced both by the proportion of the population that is partnered, and the fertility behaviour of those who are partnered. In many countries, including Australia, partnership rates have declined, and an increasing proportion of the population is single at any point in time. This paper examines how Australian fertility rates, from 1991 to 2019, have been affected by changing relationship patterns, and particularly the increasing rate of singlehood. We find that the decline in the proportion who are partnered has had a negative contribution to fertility levels, particularly at the younger ages.