It seems that once every two or three generations we have to put up with a recrudescence of Malthusian doom-and-gloom. If I recall my History of Economic Thought lectures correctly, Thomas Malthus, an Anglican clergyman and contemporary of David Ricardo, posited that population increases at a geometric rate while farm output (food, basically) increases at an arithmetic rate. (If you want to visualise this, imagine a graph of population over time as an upward-sloping curve and a graph of farm output over time as an upward-sloping straight line.) Hence population would increase for a while, but then famine would bring population levels back down.
In ‘The Essay’ in Saturday’s Sydney Morning Herod, Professor Garry Egger, who has floated the idea of population control through financial penalties of large families in an article in The Medical Journal of Australia, rehashes some of the more hysterical neo-Malthusian arguments, and all with a predictable atheistic sub-text (ironic, given Mr. Malthus’s own beliefs, but they share similar recommendations, namely the necessity of ‘moral restraint’). Hence his reference to how “[s]pecific religions also keep the discussion [of population control] muted for purposes of wanting to increase their dominance” (which is quite preposterous) and to how “we let bigoted religious belief be mistaken for political correctness so we were unprepared to challenge anything in the name of someone's God”, which is also preposterous, since we see all too frequently that Christians are ridiculed and vilified with flagrant disregard for political correctness; in fact, atheism, or at least functional atheism, is really the dominant world-view in most Western countries, and we see the likes of Dawkins, Hitchens and Onfray making quite a profitable industry out of it. And I might add that ‘specific religions’ and ‘bigoted religious belief’ are really just code for the Catholic Church, since no-one else seems too fussed about contraception.
Prof. Egger also does not seem too clear about the economics of the question. He refers to diminishing returns and speaks of regret at “laughing at the wisdom of our elders” such as Adam Smith, but it is not clear what he is talking about here, since as the Nobel economics laureate Prof. Kenneth Arrow (who, though not a Catholic, is a member of the Pontifical Academy of Social Sciences and a father of six children) pointed out, Smith “did indeed have a theory of growth, based essentially on increasing returns” (Euro. J. History of Economic Thought, Autumn 2001). Therefore if Smith has any bearing on the matter, it might in fact be in contradiction to Prof. Egger’s views.
Furthermore, his treatment of the notion of a ‘replacement level’ of reproduction seems erroneous. He says that
Two children per couple, however, is replacement value only as long as parents and children move over to give room to the next generation. If parents reproduce at, let's say 20 years of age, and live till 80, two mouths have become eight by the time the original two pass on. China's one-child policy shows this, with an extra 3.7 billion people added since the policy came into place in 1979, even though 400 million births have been prevented.
But the human race did not start yesterday; there are at any given time two or three generations already co-existing—it’s not as though there is now only one generation, and then this generation produces a new generation, and so on until the first generation dies out.
Fundamentally, the problem with Malthusianism is that it ignores technological progress by restricting itself to only two variables, namely population and output. Malthusianism is plausible enough in the short run, if we take this to mean the time frame in which the techniques of production are fixed. But these techniques improve over time, so that output can keep pace with population growth in the long run. Mankind made the transition from wind to coal, then from coal to oil, and in future it will make the transition either from oil to nuclear or directly to renewables. Those transitions will always be bumpy, but never catastrophic. The humane way to avert population crises, then, is not to penalise people for fulfilling God’s command to be fruitful and multiply, but to subsidise research and development.