Population statistics: Does child survival limit family size?

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Hans Rosling (1948–2017), physician and epidemiologist, famously upturned assumptions widely held by the public and by the development community — assumptions that, thanks to US President Donald Trump, are back in the spotlight. A recurring theme of Rosling's was that family sizes have been shrinking even though child survival rates have improved (see, for example, Nature 540, 330333; 2016). Although reducing infant mortality is an unfettered good, we are concerned that key family-planning initiatives could be lost if governments uncritically assume that it leads to people having fewer children.

Rosling's global statistics on total fertility rate and infant mortality rate do not indicate causality, neither are they necessarily correlated. Although such a correlation holds for Asia, it does not in Africa. The infant mortality rate in Niger, for example, has fallen by two-thirds since the 1980s but the country's total fertility rate has risen slightly, leading to a predicted population explosion from 20 million in 2015 to 72 million by 2050 (see go.nature.com/2j7rzcv).

In our view, President Trump's reinstatement of the Mexico City Policy (the 'global gag rule', which denies US funds to foreign non-governmental organizations associated with abortion counselling and referrals) will be disastrous for population control and for women's health. When President George W. Bush imposed a milder version of this rule in 2001, the unofficial abortion rate in African counties rose steeply (E. Bendavid et al. Bull. World Health Organ. 89, 873880; 2011). US politicians must grasp that the best way to prevent abortions is to invest heavily in accessible family planning.

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  1. University of California, Berkeley, California, USA.

    • Malcolm Potts &
    • Alisha Graves
  2. Johns Hopkins University, Maryland, USA.

    • Duff Gillespie

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  1. Report this comment #69435

    Brian Sanderson said:

    The ecologist Paul Colinvaux formulated biological theory for the human breeding strategy back in the 1970's. It answers your questions and certainly explains why infant mortality and family size are not simply related.

    Colinvaux wrote two very readable books that touch on the matter: "Why Big Fierce Animals are Rare" and "Fates of Nations; a biological theory for history".

    Trump is just a tack-on to a long list of Republican Presidents who did everything they could to limit access to family planning.

    Of course, there is nothing to stop other governments jumping in to make up the family planning shortfall.

    Meanwhile, we should be mindful of the inspiring words of Turkey's Erdogan who advocates that no Muslim should consider family planning or birth control. http://www.bbc.com/news/world-europe-36413097

    Trump and Erdogan: Twins, only their mother could tell them apart.

  2. Report this comment #69573

    David James said:

    In the correspondence published in the Feb. 23, 2017 edition of Nature Malcolm Potts and Alisha Graves were pointing out that a recent order by President Trump to reinstate the Mexico City Policy is likely to cause an increase in worldwide population and an increase in abortions. President Bush is blamed for causing such in a similar order in 2001 based upon an increase that occurred after that time. It was stated "US politicians must grasp that the best way to prevent abortions is to invest heavily in accessible family planning". Is it the role of the US, with the largest debt in the history of mankind, to spend millions of dollars for other countries to control their populations? Let's assume the statement is accurate that the best way to prevent abortions is to invest heavily in accessible family planning. That does not have to include funding abortions. Funding abortions is an area of moral policy, not just science. In fact science has shown beyond all doubt that the unborn human fetus is just exactly that – human. The age of viability has steadily decreased over the past 44 years abortions have been legal in the US. We have lost 50 million lives in that time. Who knows if one or more of those lives could have brought about answers to some of our problems?
    We as a people must grasp the concept that taking human lives before we have to face them speaks volumes about our society's humanity.
    David M James MD
    Family Physician

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