In his book The Tyranny of Numbers, Nicholas Eberstadt laments the failure of most of today's college educated persons to have even the most rudimentary understanding of basic mathematical principles. My own experience is that no where is this more evident than in discussions involving compound rates of change (called geometric or exponential growth rates). I frequently have found that although graduate students may know what buttons to push on their calculators, they have no concept of the implications of small changes in compound rates over long periods of time and, hence, can fail to correctly make even the most elementary inferences regarding long term consequences.
Let's take a concrete example. Most persons agree with economists who state that an inflation adjusted growth rate of the U.S. economy of 3% would be quite satisfactory. Yet many of these same persons will chastise their brokers if the returns on their portfolio are less than 10% annually, despite the impossibility of maintaining such a rate over the long run.1
An even more significant example is the lack of concern in this country that the population of the world is increasing "only" 1.7% annually. Even when told that this equates to 219,000 persons a day or 80 million persons a year, few people get excited.
The reason people fail to appreciate the implication of seemingly low compound rates of growth may be in part because the human species tends to have a very short time perspective, rarely longer than their own lifetimes, and most often not more than a few years. In the short term, small changes in compound rates of change matter little. This is the primary reason Malthus is still often dismissed out of hand, although he demonstrated conclusively that compound rates of growth in population must ultimately lead to disaster. Moreover, inasmuch as no world wide disaster has yet occurred in the two hundred years since his famous essay, it is even more tempting to dismiss Malthus and the neo-Malthusians as latter day Cassandra's - pessimists that refuse to acknowledge a failed theory.
Yet Malthus' observation that "population when unchecked increases in a geometric ratio" is an incontestable fact. If the birth rate had stayed at the level of Malthus' day it would yielded over 500 billion persons by the end of the coming century. Of course the dire consequences foreseen by Malthus - war famine and disease would have never permitted that number to be attained. However, the developed countries took a more prudent course and reduced their birth rate as their death rates declined. The problem is that since W.W.II the death rates of the Less Developed Countries (LDCs) fell precipitously and they have not yet reduced their birth rate proportionately.
In fact many of them are just beginning to recognize the need to do so. In 1986 I gave a lecture to a group of 14 national planners from Less Developed Countries. Although all had advanced degrees, only one understood the implication of a compound growth over many years. The representative from Kenya, which at the time had the highest growth rate in the world, stated that his country had too few people; in his opinion they were not growing fast enough! The population of Kenya at the time was 17 million and was growing 3.7% per year. I asked him to take a guess as to what the population of Kenya would be in 100 years at that rate of growth. His answer was "60-70 million." When I had him work out the correct answer using the compound growth function in my calculator he refused to believe that the answer was 643,000,000!
The majority in Congress still fail in recognize the ultimate impossibility of maintaining even the current rate of population growth. Consider the implications if we fail to reduce the world's birth rate much further. At a rate of 1.7% annually, the population of the world would soar from 6 billion to 168 billion in only two hundred years, and in 1000 years time would literally cover the earth with 127 trillion people.2
Again this will never happen because of physical constraints. Malthus posited that the supply of food would be the ultimate constraint, but their are several other constraints to be considered such as waste disposal, energy, rising conflicts due to overcrowding, and the ultimate constraint - physical space.
The more relevant criticism of Malthus is the belief expressed in his earlier work but modified in his more comprehensive second work that given the sex drive in humans, we would not be able to check our birth rate by any means other than human misery such as famine, disease or war. His pessimism was echoed by Charles Galton Darwin, the grandson of Charles Darwin, who believed that if the human species behaves like every other species, the genes of the high breeders will be proliferated to eventually crowd out the genes of those responsible persons who have fewer offspring thus fulfilling Malthus' most pessimistic prediction.
We must work to avoid this calamity. The key is to increase the cost/benefit ratio of having more than two children.
There are three ways to do this. The first is to raise the actual cost/benefit ratio by eliminating all welfare and tax deductions for more than two children while simultaneously offering more opportunities to women in the work place. The U.S. has followed the latter half of this prescription in the 1970s and it worked well for middle class and upper class families who lowered their birth rates to well below reproduction level. In 1997 they began working on removing the child subsidies which hopefully will reduce births to poor women.
The second is to change the perceived cost/benefit ratio. (The position of children vis-à-vis other "consumer" goods on the utility curve). It has long been observed that the luxuries of one generation become the necessities of the next. People are less likely to give up perceived necessities to have additional children. Oddly, TV advertisements has done much to increase perceived necessities. (As has increased education requirement.)
The third method, which was advocated by J. S. Mill, is moral persuasion - using public opinion to condemn persons for having large families. Mill argued that having a large family was a form of over indulgence like drunkenness.
With regard to all three methods of reducing population growth, the U.S. made a huge mistake in subsidizing single parent and teenage births through welfare payments. By providing such aid we lowered the cost/benefit ratio and tacitly condoned teenage and unmarried mothers. We need to eliminate all forms of subsidies for children and rekindle the concept of shame for unwed mothers. For teenagers, the only options should be adoption or abortion. Such a policy would not only reduce the number of children raised in psychologically and financially deprived conditions but would significantly reduce our population growth. The moral norm to be established should be Having children that cannot be supported financially and emotionally, is a form of child abuse.
The attitude of the Catholic Church, the Mormons and some fundamentalist sects still present a primary obstacle to bringing population under control. Of the major religions only the Roman Catholic Church condemns all forms of artificial contraception. Luckily for the human race, the vast majority of Catholics in the developed countries have more sense than to follow such an absurd doctrine. But many persons in the LDC still follow the teachings of the Vatican. Ironically, and tragically, the Pope's prohibition on contraception is the leading cause of abortions in the Catholic LDCs and a leading cause of death among women of childbearing age. Given the unimaginable amount of pain and suffering caused by the Vatican's prohibition on contraception, many persons believe that it is only a matter of time before the Church changes its position. Indeed the vast majority of laity and even the clergy would seem to favor such a change. But don't expect the pope to recant his position any time soon. Long before he became Pope, John Paul II recognized that changing their position on this issue would undermine the papacy's claim to infallibility and the living representative of God.
In 1966 he wrote, "If it should be declared that contraception is not an evil in itself, then we should be forced to concede frankly that ... for half a century the [Holy] Spirit failed to protect Pius XI. Pius XII, and a large part of the Catholic hierarchy from vary serious error. This would mean that the leaders of the Church, acting with extreme imprudence, had condemn thousands of innocent human acts, forbidding, under pain of eternal damnation, a practice which would now be sanctioned. The fact can neither be denied nor ignored that these same acts would now be declared licit on the grounds of the principles cited by the Protestants...."
In short, the Vatican is in a box created in 1870 when Pope Pius IX at Vatican Council I took the extraordinary step of proclaiming the papacy as infallible when making pronouncements on faith or morals.3 The world has been paying the price ever since.
Immigration will still be a problem even if world population is brought under control
In the U.S. we have largely solved the problem of excessive birth rates in the aggregate in 1970s, (although some groups are still having too many children). Nevertheless the threat of over population remains because of our excessive immigration problem which is exacerbated by the high birth rates of immigrants. Even if we could solve the problem of excessive birth rates world wide, we still face the problem in the U.S. as long as it benefits the four billion poor of the world to migrate here.
It is a classic case of Garrett Hardin's "Tragedy of the Commons," where private benefits/ public costs , employers promote immigration. Ironically, today's labor union leaders fail to recognize the fundamental rule of supply and demand in determining wage rates. Union leaders are fully cooperating with short-sighted management in promoting a policy that will ultimately turn the U.S. into a third world country.
If there is a temporary shortage of labor in a specific occupation it should be met through a temporary immigration program where employers are forced to pay a tax to offset the public cost and ensure that there is no advantage to hiring immigrants over indigenous labor. TSC
1 Of course this includes inflation. But even after adjusting for inflation perons are satisfied with a real rate of return of 5 to 6 percent.
2 There are those Pollyannas who place unbounded faith in our ability to colonize other planets. But as Kenneth Boulding points out even if we could support life on every planet in every star system in the universe, we would still run out of physical space in 8000 years. And Garrett Hardin explains the physical constraints that make mass migration to other solar systems ludicrous. Even at the incredible speed of 22 million mph, it would yake 140 years to reach the nearest star. Moreover, the cost would be tens of millions of dollars per person. Interstellar travel makes for good science fiction, but the reality is that 35 years after we put a man in space we have not figured out how to get to Mars which is the equivalent of a stroll around the block.
3 Ironically, the idea of papal infallibility was condemned in 1324 by Pope John XXII as a work of the devil. Hence we have two popes who contradict one another, yet both were subsequently proclaimed infallible.