‘Missing births’: assessing the impact of fertility postponement on the changing number of births in Europe

Tomas Sobotka, Vienna Institute of Demography

Most European societies have experienced marked decline in the numbers of births during the last decades. This study discusses various possibilities of decomposing changing numbers of births, starting from a basic decomposition that distinguishes fertility tempo, quantum, and ‘mean generation size’, and illustrating further extensions of this decomposition. The empirical analysis focuses on the impact of the three main components on the declining numbers of births from the beginning of fertility postponement in 13 European societies. This research reveals a considerable cross-country variability. The analysis of the past trends may serve as a basis for projecting future changes. We argue that an explicit incorporation of fertility timing component can make projections of fertility and births more realistic and transparent. Using examples of three countries with different intensity and duration of fertility postponement we show how the eventual stabilisation of the mean age at childbearing may affect future numbers of births.