Saturday, April 23, 2005

How many people?

Malthusian Twaddle
by Ronald Bailey

It turns out that dissenting from the popular dogma that the world is about to be overwhelmed by a population explosion tends to provoke people. Many readers of my column about Real Environmental Racism decided that I might finally see the error of my ways if I would just read Daniel Quinn's novel Ishmael: An Adventure of the Mind and Spirit. So I read it.

The book opens with the protagonist responding to this advertisement: "TEACHER seeks pupil. Must have an earnest desire to save the world. Apply in person." The unnamed protagonist (pretty clearly a stand-in for the author), after some gnashing of teeth, goes to a nondescript office building where he meets Ishmael, the teacher who placed the ad.

The twist? Ishmael is an elderly telepathic gorilla who for years has studied humanity at the behest of a rich benefactor, and is now in a position to offer deep insights about our species from an outsider's objective point of view. And what are these insights? Pure simple-minded Malthusianism.

Badly modeled on Plato's Dialogues, the novel is a series of long conversations between protagonist and ape, during which the gorilla essentially rehashes Thomas Robert Malthus' arguments in his first edition of An Essay on the Principle of Population. "Population," Malthus famously asserted, "when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. This implies a strong and constantly operating check on population from the difficulty of subsistence."

Ishmael echoes the sentiment: "[A]ny species in the wild will invariably expand to the extent that its food supply expands." In other words, the goal of all species is to convert food into offspring, and more food means more offspring. What's more, "In the natural community, whenever a population's food supply increases, that population increases. As that population increases, its food supply decreases, and as its food supply decreases, that population decreases. This interaction between food populations and feeder populations is what keeps everything in balance."

In the real, non-idealized world, the population of our human ancestors was kept "in balance" (i.e., low) by high mortality rates for infants and mothers. "For hundreds of thousands of years as hunter-gatherers, and subsequently in agrarian societies, our predecessors had an average life expectancy of 25-30 years," Australian epidemiologist Tony McMichael has pointed out. "Most of them died of infectious disease, and many died of malnutrition, starvation and physical trauma." In other words, Ishmael's "balance" is just a euphemism for starvation and disease.

Our supposedly enlightened gorilla calls civilized humanity the "Takers," in contrast to the remaining bands of hunter-gatherers, whom he christens the "Leavers." Modern civilization, he argues, has violated what he calls the "peace-keeping law," which mandates that "you may compete to the full extent of your capabilities, but you may not hunt down your competitors or destroy their food or deny them access to food." Ishmael illustrates this alleged "law" by claiming, "the lion that comes across a herd of gazelles doesn't massacre them, as an enemy would. It kills one, not to satisfy its hatred of gazelles but to satisfy its hunger." He's implying that lions and other species are "prudent predators," that is, they are careful to preserve a breeding population of its prey species in order to insure the survival of its own species.

But as evolutionary biologist Richard Dawkins has pointed out, the concept of prudent predators is evolutionarily incoherent. Such an arrangement could not remain stable, because a single mutant that became a selfish exploiter would quickly outbreed the "prudent" members of its species. In other words, genetic evolution cannot confer this type of foresight on species—short-term advantage will always out-compete long-term prudence.

Ishmael makes another factual error when he swallows the myth of the noble savage living in harmony with nature. He sagely informs our hero that the American Indians "were looking for ways to achieve settlement that were in accord with they way they'd always lived, ways that left room for the rest of life to go on around them."

Complete twaddle. Those early immigrants from Asia were responsible for killing off the Pleistocene megafauna, such as mammoths, mastodons, and giant ground sloths. Similarly, the primitive people who arrived in Australia some 40,000 years ago devastated that continent's wildlife. Primitive peoples are no worse than other animal predators, just more effective. Despite this history of depredation and disease, Ishmael's advice is that civilization must return in some fashion to the ethos of primitive humanity. How to do that, he leaves up to us.

Fortunately, civilized humanity is solving the problem of long-run prudence by using culture. As our civilization develops, we are becoming better at foreseeing the consequences of our actions, and have built institutions that encourage long-range thinking. Private property is one such vital institution, because it forces people who reap the benefits to bear the costs of using a resource. Private property is a cultural institution that turns people into real "prudent predators." Both coyotes and men eat sheep, but while more coyotes mean fewer sheep, more men mean more sheep. Ishmael's flawed anthropology overlooks the fact that Amerindians, like the Mesopotamians before them, independently invented agriculture and civilized life to overcome the food shortages that plagued their hunter-gatherer ancestors after they ate all the big tasty animals they could catch.

Quinn's dim protagonist makes the telling observation: "The biological community is an economy, isn't it? I mean, if you start taking more for yourself, then there's got to be less for someone else, for something else. Isn't that so?" Ishmael answers, "Yes," thus disappearing along with our protagonist down the usual Malthusian zero-sum rabbit hole.

The fact is, our supposedly resource-plundering civilization is actually creating new resources. Tripling crop productivity over the past 40 years has spared hundreds of millions of acres of wildlands from being plowed down to grow food. Future farming should leave more, not less land for nature.

But still, you may wonder, doesn't wise old Ishmael (and his creator Quinn) have a point? As humanity's food supply has increased, hasn't population burgeoned? The gorilla further argues that food produced by Nebraska farmers is fueling population growth in poor parts of the world. (The question of why each Nebraska farmer doesn't produce a couple dozen children himself and feed his progeny all that excess food goes strangely unaddressed.) In fact, the countries in which people consume the greatest number of calories are precisely the countries with the lowest fertility rates: the U.S., Canada, Europe, Japan, and so forth.

Ishmael ignores the real demographic trends that contradict his dire thesis. Demographers agree that if current fertility and mortality trends continue, human population should peak by mid-century at around 8 or 9 billion, then begin falling. In fact, the United Nations' low-end population projection foresees humanity's numbers maxing out at less than 8 billion around 2040, and beginning to fall thereafter.

In other words, Ishmael gets it exactly backward: Civilized humanity is actually more prudent than primitive man. If there is such a thing as a "prudent predator," we are it. Unlike other species and our hunter-gatherer forbears, modern man does not just blindly convert food into offspring.

In the end, all that Ishmael proves is that Malthusianism remains a simple, powerful idea that is simply and powerfully wrong.