Who Defused the Population Bomb?

Fred Pearce has a nice article (in Grist of all places) about how the Population Bomb essentially defused itself.

For a start, the population bomb that I remember being scared by 40 years ago as a schoolkid is being defused fast. Back then, most women round the world had five or six children. Today's women have just half as many as their mothers -- an average of 2.6. Not just in the rich world, but almost everywhere.

This is getting close to the long-term replacement level, which, allowing for girls who don't make it to adulthood, is around 2.3. Women are cutting their family sizes not because governments tell them to, but for their own good and the good of their families -- and if it helps the planet too, then so much the better....

And China. There, the communist government decides how many children couples can have. The one-child policy is brutal and repulsive. But the odd thing is that it may not make much difference any more. Chinese women round the world have gone the same way without compulsion. When Britain finally handed Hong Kong back to China in 1997, it had the lowest fertility in the world -- below one child per woman. Britain wasn't running a covert one-child policy. That was as many children as the women in Hong Kong wanted.

This is almost certainly one of those multiple-cause things, and we have always had the hypothesis that wealth and education reduced population growth.

But the author makes an interesting point, that urbanization, even in poorer countries, may a big driver as well.  After all, in the city, food and living space for children are expensive, and there are fewer ways children can support the family (I hadn't thought of this before, but I wonder if industrial child-labor restrictions, which mainly affected cities, had an impact on birth rates by making urban children less lucrative?)  In fact, urban jobs require educations which are expensive  (even if they are free, non-productive family members must be fed and housed for years).


  1. morganovich:

    i think that point about urbanization is dead on.

    on a farm, kids are labor and wind up paying for themselves.

    in a city, kids are just an expense.

    the most common reason i hear for not having kids is not being able to afford them.

    given that HK has some of the most expensive real estate in the world, shouyld it surprise us that people don't have kids there or that those who do move away?

  2. blokeinfrance:

    Look at population statistics for China and you'll see that fertility was plummeting before the one child policy and before the urbanisation and industrial boom. Something else going on, surely, but what?
    Some candidates: farm mechanisation, migrant working, cultural change (a preference for quality over quantity), people actually being quite good at anticipating the future, changes in relative prices (housing / food)?
    The most likely candidate to my mind is simply the decline in child mortality. If your children are more likely to reach adulthood you need fewer of them to assure your own survival in old age.
    I'd like to see a comparison between say China post Mao and US post civil war. Would we see a similar demographic pattern?

  3. TVH:


    Please read Mark Steyn's "America Alone" which is about demographics in general and demographics and immigration in Europe in particular. It covers this topic in great detail. It used to be that kids out on the farm became cheap farmhands, and only 3 or 4 of the 10 kids a woman had made it to adulthood anyway. Now, most of the 1-3 kids she has in the city live to become adults, and whereas they used to be a profit center (extra farm revenue at close to 0 cost), they are now a cost center, what with food, expensive space, education, Ipods, cellphones, video games, college, etc.

    In the past couple of decades, just about everytime the UN or someone projects world population in 2050 or 2100, the number drops lower than the last model results predict, because of the trend you discuss here. Last time I checked the number was something like 8.9 billion (peak) in 2055, and by 2100 the number is lower than today, something like 6 billion. Now, by 2100, we may have technology (per Kurzweil) to make us effectively immortal so I don't think they factored that in. Anyway, good post...


  4. Gil:

    Of course the comeback is that children are deadweight expenses because the government forbids by law children from earning their keep. However by Julian Simon's reckoning mothers should still be having six or more children each with all of them reaching adulthood causing the population to expand exponentially yet technology will there to feed and house them all forever.

  5. John Dewey:

    The birth control pill was only approved for oral contraception in most Western nations in the mid-1960s (for example, SCOTUS 1965 Griswold vs Connecticut). It now seems incredible, but it was not until a 1972 Supreme Court decision (Eisenstadt v. Baird) that unmarried women had the right in all 50 U.S. states to possess and use oral contraceptives.

    The baby bust which started in the U.S. in 1965 coincides exactly with the widespread adoption of the pill. IMO, women desired to limit fertility before 1965, but did not have the means to effectively do so.

    The Pill defused the population bomb.

  6. Hunt Johnsen:

    Is this reduction of birth rate true of muslims immigrants or islam in general as well? I've heard references to muslims conquering Europe with their wombs.

  7. caseyboy:

    Maybe its statistically insignificant, but lets not forget that abortions take perhaps tens of millions out of the equation each year.

    It is also interesting to look at birth rates among ethnic groups. I don't have the statistics handy, but I seem to recall that the European birth rate will not replace the current adult population with couples having an average of 1.4 children. Muslim couples tend to have much larger families. Those European countries with large Muslim communities are starting to pay attention to this trend line.

  8. Mike Mann:

    >> Who Defused the Population Bomb?

    The answer is obvious. Paul Ehrlich did.

    He wrote about it, and that dumb son of a b.... has never managed to get ANY prediction right.

    Considering that even a busted analog clock is correct twice a day, Ehrlich should have gotten something right after 40 friggin' years.

    Ergo, it is clear that he has the psychic ability to force things to go against his predictions.

    It's statistically provable.


    I've done it.

    No, you can't see my data...

  9. Gil:

    Well, J. Dewey, who'd have thunk it: women aren't tickled pink at the thought of having umpteen children? Fancy that? Women have go through all those wacky nine months only to go the pains of childbirth. Yet for some reason when women are given reproductive choice they don't want to have many children.

  10. Douglas2:

    One classic explanation is that old-age security required one to have enough offspring to support you in your dotage, and this explains that as child mortality falls in any country the birth-rate also falls within a generation.

    The comments above about European birth rates falling below replacement level made me think that we have, in modern western nations, created a "tragedy of the commons":
    We have put in place publicly funded pension systems such as Social Security in the USA. Everyone can draw from them, but for continued solvency these need contributions from working-age persons to fund retirees. There is no personal cost, however (and perhaps much personal gain) from not contributing offspring into the system.