Redefining fertility replacement level for populations with positive net immigration

Redefining fertility replacement level for populations with positive net immigration

In almost all the More Developed Countries the Total Fertility Rate (TFR) is below the “approximately 2.1’ replacement level, which in the absence of sustained immigration would prevent a long run population decline. In most of these countries net immigration is positive. This paper proposes and calculates for 22 populations for 2011-15 a ‘Current Migration Replacement TFR’ which is coherent with zero population growth in combination with the prevailing absolute amount of net migration (and mortality level), and sits within a broader suite of ‘replacement levels’ which spans all the components of population change. The results show the Current Migration Replacement TFR ranges widely from 0.60 for Singapore to 2.05 for Slovakia. That the Current Migration Replacement TFR is below the 2011-15 TFR in 14 of the 22 countries shows that, when considered in combination with current migration and mortality, in most of the countries the current ‘below 2.1’ TFR is coherent with population increase, not population decline, over the long run. For New Zealand, Australia, Norway, Sweden and the UK continued current fertility in combination with constant mortality and constant absolute net migration is shown to be coherent with more than doubling of the current population size. The value of Current Migration Replacement TFR’ for illustrating the interconnected population size implications of sub-replacement fertility and immigration, for sub-categorisation of ‘post-transitional’ populations by population growth prospect, and for guiding population policy is discussed.

The paper was published on 5 August and can be found at:

Nick Parr holds a PhD and MSc in Social Statistics from Southampton University (UK) and a BSc(Hons) in Mathematics from Warwick University. He has lectured at Macquarie University since 1992, mostly in the field of demography. His research interests include; fertility, contraceptive use, family policies, population projections, workforce demography, immigrant populations, health, mortality, applied demography, population economics, statistical demography and mathematical demography. Whilst most of his research has focused on Australian demography, he has also published papers on West African and Asian countries, most notably Bangladesh, Ghana and Indonesia, and a range of multi-population studies. He served for ten years (1996-2006) on the National Council of the Australian Population Association (APA), being National President from 2002-04 and National Vice President from 2000-02. He was President of the NSW Regional Group of APA from 1997-2001, Conference Convenor for the 2002 Conference of the Australian Population Association and Program Convenor for the 2016 Conference.


Date & time

Tue 11 Aug 2020, 2:30pm to 3:30pm


By Zoom (ID: 915 1095 6787 PW: 659951)


Professor Nick Parr, Macquarie University


Susan Cowan


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