Energy Use and Population Growth
tỷ lệ cá độ bóng đáWillian Stanley Jevons was a 19th century economist who is most famous for formulating what is now known as the Jevons Paradox: technological progress that increases the efficiency with which a resource is used, tends to increase (rather than decrease) the rate of consumption of that resource.
I've just started reading the book The Jevons Paradox and the Myth of Resource Efficiency Improvements. I'll be reviewing the book itself later, but right now I want to post some thoughts that came up as a result of reading the foreword.
The foreword is by Joseph Tainter, author of the book The Collapse of Complex Societies, which is somewhat famous in doomer circles. In the foreword he discusses some areas where we see Jevons's theory at work in our everyday lives, including an interesting look at the increase in police weapons use due to the lower personal cost to the officer of using a Taser versus a handgun. One of the things he mentions in passing is the cost of raising children, with the comment that Jevons might predict that as the cost of raising kids went down we might have more of them. That made me say, "Hold on, we're seeing exactly the opposite! As societies get richer, which lowers the cost of everything including children, their fertility rates drop! What's going on?"
Then I remembered a quote earlier in the foreword, which clarified the law of supply and demand with one crucial word: "Any time one reduces the cost of a valued resource, people will respond by consuming more of it." A little light bulb blinked on. If the value the consumer places on a good drops, even lowering the price will not tempt more consumption. Perhaps the value societies place on children is changing, and that change is causing some of the drop in birth rates we're now seeing.
My hypothesis is that increasing energy use lowers the marginal value of children as labour.
To generate the hypothesis I followed this chain of thought:
The correlation is clear. Countries with high levels of energy use tend to exhibit low fertility rates, and vice versa. What this seems to imply is that increasing energy use is one of the most significant mechanisms driving Stage 3 of the Demographic Transition (possibly up to half the total influence). This relegates all the other factors such as contraception, urbanization, education, female literacy, etc. to supporting roles, as they split the remaining 50%. The primary factor in reducing population growth rates is shown to be rising energy use that displaces the value of human beings as labour.
What this finding might mean for an energy-constrained future needs more reflection, but if the hypothesis holds up there could be significant upward pressure on birth rates in such a world.
August 18, 2008
© Copyright 2008, Paul ChefurkaThis article may be reproduced in whole or in part for the purpose of research, education or other fair use, provided the nature and character of the work is maintained and credit is given to the author by the inclusion in the reproduction of his name and/or an electronic link to the article on the author's web site. The right of commercial reproduction is reserved.