TED Conversations

John Taves

This conversation is closed. Start a new conversation
or join one »

The conventional wisdom of demographers is fundamentally flawed.

In the conversation "Why do so many think that population growth is an important issue for the environment? Don't they know the facts of demographics?" Hans Rosling uses the "facts" of demography to argue we don't have to worry about population growth. Demographers have fundamental flaws in their thinking. In short, they are dead wrong.

Consider a belief that has these 2 characteristics: 1) believers average more than 2 children, and 2) they successfully pass along that belief to the next generation to at an average of at least 2 of those children. This belief will overpopulate the planet. Imagine that 99% of the population are non-believers, and 1% are believers. It would take many generations for the believers to rise to sufficient numbers so that demographers would notice them, but in the end, the birth rate will be determined by the believers.

This logic shows us flaws in the data collection and interpretation techniques that demographers use. Demographers must prove that these belief characteristics cannot exist if there is any hope that the downward trend of birth rates will continue and stay at or below an average of 2 children.

Their sampling techniques filter out beliefs that are passed to the next generation. This error means that if demographers tried to find groups that have beliefs that are not behaving according to the demographic transition predictions, they won't find them in their data.

Demographers use extrapolation techniques to predict future birth rates, but the logic dictates that they must find groups that are averaging the most children, and monitor their growth.


Showing single comment thread. View the full conversation.

  • Apr 23 2012: I think you make a good point.

    What you're saying is that while it may be true that "on average" people tend to have less children as they get more affluent, it doesn't mean that the population will eventually peak or even slow down.
    This is because it only takes one subgroup to buck the "average" behaviour and continue to keep having lots of children even as they grow more affluent and eventually that subgroup will become a majority, and then the "average" behaviour will be to have more children even if affluence increases.

    I think you've identified a fatal flaw. Well done.
    • Apr 23 2012: Yes, that is a correct interpretation of what I am trying to convey.

      I will add that I also reject the demographers conclusion that affluence causes a lower birth rate. I agree it seems to correlate to it, but correlation is not a mechanism. We certainly know one mechanism, and that mechanism is opposite of their correlation findings. Averaging more than two children causes our numbers to attempt to grow to infinity, and nature can only stop that growth by killing children. That is poverty. Averaging more then two, eventually causes poverty.

      Oh, and another thing. I will not say that the population will not eventually peak. It will peak regardless of how we behave. That is the nasty reality of being on a finite planet. Please also see http://www.ted.com/conversations/10955/the_conventional_wisdom_of_dem.html (oops, that is this conversation. I meant http://www.ted.com/conversations/10956/humans_have_almost_always_been.html).
      • thumb
        Apr 26 2012: If I was to try and boil your hypothesis down to a lamens comedy routine.

        Basically, smart people stopped having random reproductive sex, and started family planning, about 50 years ago... So, while it has seemed like the population was leveling out and getting smarter... Underneath it all... Stupid people, who had previously been on the decline, were just bangin away, and indoctrinating their children with nonsense.

        Now... The population didn't rise as fast as expected, but a whole bunch of smart people, have been repopulated by stupid people... and now our population is going to explode, with no one left who knows enough science to save us?

        Poetic isn't it?
        • Apr 27 2012: I enjoy the humor. But I cannot help pointing out a flaw... I just can't hold back.

          Assuming the stupid smart thing is humor, then the flaw is to assume that the population will rise. If we average more than 2, we attempt to grow the population exponentially. Whether it grows or not is determined by the capacity of the environment to provide for the increase. We certainly might be able to be more efficient at getting our sustenance, but given that the planet is finite, we cannot be infinitely efficient, and thus there is a limit.

          This is not some minor point. The UN estimates for future populations predict a peak of maybe 9 billion. Many people mistakenly use this as some sort of proof that there is no long term population problem. The fact that the population will peak is not news worthy. It must peak given that this planet is finite. Will it peak because we comprehend we must manage the birth side of the equation so that the death side is not forced to stop the growth?
      • thumb
        Apr 27 2012: Oh... I think we're going to get to 12 or 13 billion before we reallize that 10 was unsustainable, as people who've been living exclusively on corn syrup start dropping dead at 25. I don't think we're going to hit the peak because we saw it coming and reacted, certainly the believers, who are in the vast majority won't... they don't believe in reacting to stimulus, they don't believe in facts, or numbers, or experiments. They believe that god created humanity, and loves us more than anything else, so we should just have faith in him, and everything will be alright.

        It's not just stupid, it's actually willful ignorance, it's intentional... it's evil. They want to believe that everything they do is right, no matter how horrible the consequences of their actions are, it's psychopathic behavior, but non believers / smart people... aren't calling them out for it. We believe in post modernism, and moral relativism now, so everyone has a right to believe whatever they want, no matter how destructive it is.

        Anyone else reminded of the old expression "The greatest trick the devil ever pulled, was convincing the world he didn't exist". If there is any group of organizations, that is constantly intentionally manipulating children into a violent and unsustainable life, it's the various modern religious organizations... Yet we constantly tell ourselves "but they're mostly nice people, and they mean well"... Thus, in terms of sexual selection... They're kicking our ass, and now they run the show again.

        With them running the show there is absolutely no hope for humanity to move below 2 children per family... So... I would argue, that we're definately going to kill each other over resources, rather than peaking by choice, specifically because, we believe in love, god, and faith. The irony is delicious. Things are funny when they're true.
        • Apr 28 2012: I certainly agree that as the number of believers grows, it gets harder and harder to stop it. I am hoping to find people that comprehend that the only solution to prevent these beliefs is universal knowledge that a belief with these characteristics is morally wrong.

          However, note that in your writing you do not seem to use the same definition of believer that I defined above. Yours use of the word "believer" seems to cast a wider net. I want to make it clear that I do not intend to agree with that. I am sticking to the definition I provided and will not include smart/stupid, this religion or that religion.
      • thumb
        May 5 2012: Just so you know, I didn't actually mean to suggest that people who believe in religion, are all stupid, or all reproducing in unsustainable numbers. When I joked about believers in this context, being stupid, I meant people who take their religious beliefs, like "go forth and multiply", so seriously, that they don't care if the belief is sustainable. They are a part of the wider net though, and I think the secular world, and other believers, need to call them on it.
        • May 7 2012: That was the clarification I was hoping you would make. It is excellent, thanks.

          I agree that everyone needs to understand it is wrong to average more than 2 children.

          Just to be clear, "everyone" is the same set of humans that understands murder is wrong.

Showing single comment thread. View the full conversation.