Living Within Limits - Chapter 16

Trying to Escape Malthus

Observation has revealed a correlation that appears to contradict Malthusian principles: prosperous countries often have a lower fertility rate than poor countries.  This, in turn, has led to alternative theories on population and prosperity.

Sex as Anti-Malthusian?

Thomas Edmonds presented the idea that the poorer a people are, the greater will be their fertility because the only amusement they have is sex.  Among the wealthy, sex must compete with other amusements.

However, this theory is refuted by its inherent positive feedback.  In one scenario, an increase in population will lead to more misery, which leads to more sex and higher fertility, which leads to yet more population and misery, and so on and so forth.  Conversely, a decrease in population will lead to greater felicity, thereby leading to less sex and lower fertility, which feedbacks into yet sharper decreases in population...

Clearly such a theory is misguided, or at best, wholly incomplete.

Gluttony as Feedback?

Thomas Doubleday observed that, in some animals, over-feeding led to infertility.  From this, he deduced the general theory that fecundity is inversely proportional to the richness of the diet.  He used this theory to explain the relationship b/w societal wealth and fertility.

However, his flaw came from choosing examples that were unnatural.  For example, his observations were based upon human-raised swines, or domestic rabbits.  The eating habits of these particular samples have been artificially distorted.  In nature, no swine or rabbit would eat itself to the point of infertility (anti-darwinian).

Child Survival Hypothesis

Lester Brown was the one to present the theory that, by decreasing infant mortality rates, we can decrease a society fertility rates (if more babies survive to adulthood, there is less need by mothers to produce babies).

Though inconclusive, there is plenty of evidence that should give pause to philanthropists subscribing to this theory:

http://www.jstor.org/pss/2173608
http://www.jstor.org/pss/1973552

Perceived child survival chances seem to have little influence on whether or not a woman desires additional children... Reductions in child mortality may have the short-term effect of accelerating population growth, until enough experience with decreased mortality is accumulated to effect a change in fertility desires... (Research in Guatemala)

Essentially, evidence suggests that, in the short-term, lower child mortality rates dramatically increase population growth (for up to two generations).  In the long-term, there does seem to be evidence that population limits and social awareness will lead to lower birth rates.  However, Hardin argues that this is a dangerous policy to pursue, particularly in nations which already suffer from overpopulation.

The Goal

Ultimately, we must not lose sight of the needs of the poor.  The urgent is to bring greater comfort into their lives.  Though infant-mortality reduction is morally commendable, the means should not become the end.  In addition to death-control, priority should also be turned to adequate birth-control, which is what will ultimately lead to decreased birth-rates, and greater prosperity.