The Role of Contemporary Childbearing Postponement and Recuperation in Shaping Period Fertility Trends
This paper outlines a method that analyses how cohort and period childbearing postponement and recuperation (P&R) are reflected in total period fertility rate (TPFR) trends in low-fertility populations in recent decades. The method is rooted in the trailblazing ideas developed by Ryder (1951 and 1964), namely that childbearing P&R occurs in the life of individual women and can be summarised in the lifetime experiences of birth cohorts. Cohort childbearing age patterns are then translated into period childbearing age patterns and the effects of the P&R process on the TPFRs are revealed by summarising period ASFRs of young women and of older women and analysing their interaction over time in 36 low-fertility populations. The method is complementary to methods pioneered by Bongaarts and Feeney (1998) which estimate tempo-adjusted TPFRs. These demonstrate the degree to which TPFRs are distorted. The method described in this paper reveals the internal mechanism generating TPFR trends; it exposes the demographic structural causes generating TPFR trends and demonstrates why TPFRs are moving in a certain direction.
The following findings stand out:
1. All low-fertility populations have experienced TPFR troughs at some point during the past four decades. The troughs occurred because low fertility among young women of young cohorts starting to postpone childbearing overlaps with low fertility among older women of older cohorts who had not postponed births. The troughs occurred in Western countries mostly during the early 1980s and in Central andEastern Europearound 2000.
2. The structural causes of the increase in TPFRs in the late 1990s and early in the 21st century were different in Western countries compared to Central andEastern Europe. The former were experiencing the concluding phases of the P&R process. In contrast, in Central andEastern Europepopulations were experiencing the initial phases of childbearing P&R. It was a historical coincidence that TPFRs were increasing in most low-fertility populations almost simultaneously around the beginning of the 21st century.3. These TPFR increases were predominantly the consequence of changes in cohort childbearing age patterns, i.e. changes in the timing of fertility. They were not generated by fertility quantum increases. During this period in almost all the low-fertility countries TPFRs were rising while corresponding total cohort fertility rates were declining.