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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.


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  • Apr 30 2012: 'Believers' - it would be beneficial if there were a definition of what is meant by this term. My first thought was that it could refer to religious beliefs, but I have reread several times and sense that it is meaning belief in bearing large families;

    My husband and I have a large family, and that choice was made for personal reasons, but not due to religious beliefs. We have always been concerned with the global aspect of the environment and personal consumption of resources. Our family lived minimally. We never were large scale consumers. I'd actually propose that our large family consumed less than a family of 2 or 3 children where there may have been more income available for such things. Also, not one of our children wants to have a large family. So the 'characteristic' presented, in this instance, does not fit.

    In countries such as Mexico, women bear multiple children for religious reasons. A woman's status in this particular culture is raised when she has a large family. Also, machismo plays a role in the family culture. Changing this deeply embedded belief would be a cultural revolution. I agree that demographers need to focus on these cultural groups mindsets and trends in order to have a true predictor of future birth rates.

    I have twin daughters (20) who are currently using birth control. But for completely different reasons. Melinda Gates addressed valid concerns which need to be addressed globally. A woman's personal reasons for using birth control should never be the issue. Access is the issue.
    • Apr 30 2012: In this context, a believer is someone who has a belief that has the 2 characteristics described above. The particular belief does not matter, as long as it has those 2 characteristics we humans have a problem.

      For example, consider the belief "It is OK to have as many children as I want". If people that have this belief average more than 2 children, and pass this belief along to the next generation to an average of more than 2 children, then humans will suffer overpopulation.

      I assume it was not lost on this audience, and you, that you and almost everyone else on this planet believes "it is OK to have as many children as I want". Clearly it is passed along to every child. It does not matter if the belief is passed along by direct teaching, or passively like this one has been. This means that it has the 2nd characteristic. It also has the 1st characteristic too, because humans have always averaged more than 2.

      Demographers will point out that the birth rate is coming down, which is to say that they belief that this particular belief will not have the first characteristic someday. Unfortunately, they do not have proof that this will happen. They have a correlation that suggests it might happen. Even if the belief "I have the right to have as many children as I want" does indeed manage to lose the first characteristic someday, nothing stops a different belief from having those 2 characteristics.

      I agree that Melinda Gates brought up some very good issues. Access to birth control is certainly a requirement, but this logic points out that access is not sufficient.

      Notice that your own logic is the same as demographers. You pointed out how you had a lot (in the past) and your children will not (the future), but there is no guarantee commensurate with the potential harm. You also used "large" instead of "greater than 2". 2 is a magic number in this topic. It cannot be replaced with "large" and "small". Demographer make both of these mistakes.

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