THE LAW OF POPULATION

Malthus's law of population developed a point that Smith had left in disarray and was readily assimilated into the main stream of classical thought. Malthus's inquiry into the subject, however, was originally stimulated by a debate with his father over the doctrines of Godwin, an advocate of a crude form of utilitarianism who had called for the abolition of private property.

The basic argument was stated succinctly in the following propositions:

I think I may fairly make two postulata. First, That food is necessary to the existence of man. Secondly, That the passion between the sexes is necessary, and will remain nearly in its present state.... Assuming, then, my postulata as granted, I say, that the power of population is indefinitely greater than the power in the earth to produce subsistence for man. Population, when unchecked, increases in a geometrical ratio. Subsistence only increases in an arithmetical ratio. A slight acquaintance with numbers will show the immensity of the first power in comparison with the second.9

From these propositions Malthus deduced that a war between the powers of human reproduction and the production of food would be perpetual. In the nature of things, population could not exceed the limits set by the availability of food-stuffs.

The number of labourers also being above the proportion of the work in the market, the price of labour must tend toward a decrease; while the price of provisions would at the same time tend to rise. The labourer therefore must work harder to earn the same as he did before. During this season of distress, the discouragements to marriage and the difficulty of rearing a family are so great, the population is at a stand. In the meantime the cheapness of labour, the plenty of labourers, and the necessity of an increased industry amongst them, encourage cultivators to employ more labour upon their land; to turn up fresh soil and to manure and improve more completely what is already in tillage; till ultimately the means of subsistence become in the same proportion of the population as at the period from which we set out.10

Over a longer period, more forceful checks to the tendency of population to outstrip the means of its subsistence were also likely to be brought into play. In the first edition two checks - the positive and the preventive - were distinguished, though both were reducible to misery and vice. Through the positive check, population might be thinned by war, famine, pestilence, plague or disease. The outcome would be less bleak if the populace could be persuaded to exercise appropriate prudence in restraining the growth of numbers. Malthus held out little hope that this outcome could be brought to pass. In any event, he maintained that lengthy postponement of marriage would probably be associated with a rise in moral depravity and unnatural attachments.

This analysis offered only a dismal future for the human race. Mankind was left on a treadmill. Any improvement in average levels of income, the message seemed to say, would soon be neutralized by expanding numbers; wages would then be pushed back to subsistence.

In the second and subsequent editions, the argument was restated with a number of modifications. These qualifications made little difference to the public understanding of his message and indeed Malthus sometimes neglected them in his own writing. The preventive check - i.e. the restraint on population growth brought about by prudence and foresight - was upgraded with the effect of opening up some prospect for improvement in the condition of the working class. This shift in emphasis, however, involved a more substantial redefinition of one of his crucial concepts than Malthus directly acknowledged. In the first edition subsistence could generally be interpreted as referring to physiological requirements for survival. But the status accorded to the preventive checks in subsequent editions introduced a complication. Subsistence could no longer be understood in terms of survival needs. A psychological version of subsistence - i.e. the minimally acceptable level of income that a potential parent would insist upon before raising a family - was now brought to the foreground. These two interpretations of subsistence yield divergent results. Should popular tastes be elevated, the likelihood that an improvement in real income would soon be eaten up by more mouths would be considerably diminished.

In his essays on population Malthus attached little weight to the possibility of this outcome.

From high wages, or the power of commanding a large portion of tt life, two very different results may follow; one, that of a rapid increase of p case the high wages are chiefly spent in the maintenance of large and fre

the other, that of a decided improvement in the modes of subsistence and the conveniences and comforts enjoyed, without a proportionate acceleration in the rate of increase.12

This concession, however appealing as a withdrawal from the harshness of the first edition, stripped his population theory of much of its bite. No longer could it be maintained that Malthus had uncovered a scientific law with direct and immediate bearing on social reality. Instead, his principle was reduced to a tautology, empty of empirical content. Despite its appearance, the proposition that pressure of population will naturally perpetuate a subsistence wage level says nothing specific about the future condition of the working class. With growth in national output, real wages might be constant or they might rise, depending on which notion of subsistence was operative. No evidence can falsify a statement of this form. The cost of this immunity, however, is loss of contact with the world of events.

In his recommendations on economic policy Malthus largely ignored these qualifications. Moreover, most classical economists interpreted his 'principle of population’ as providing a convincing demonstration that real wages would naturally gravitate to an equilibrium at a fixed level of subsistence. Nor in the popular understanding was the gloom of the original version noticeably relieved. As one of the characters in Thomas Love Peacock’s novel, Melincourt, observed:

Bachelors and spinsters I decidedly venerate.

If Malthus’s logic was not impeccable, his interpretation of the causal mechanics of population change was also open to challenge. Malthus had argued that adjustment of population size to economic change occurred largely through effects on natality. If real incomes improved, marriages would be contracted earlier and births would increase. He assigned little importance to the possible relationships between economic improvement and reductions in mortality. There is considerable evidence to suggest, however, that the 'population explosion’ of his day was heavily influenced by reductions in death rates. These demographic changes, moreover, were linked more closely to improvements in public health and sanitation than to improvements in real wages. The facts of the case, however, are not yet conclusively established. The inadequacies of the national statistics on the British population in the late eighteenth and early nineteenth centuries are such that, as one close student of these problems has commented, a thorough understanding of the mechanisms of population growth in that era would require 'a generation of collaborative work on parish registers and other local sources’.14

With the benefit of hindsight, it is now clear that Malthus considerably underestimated the pace of technological progress and its impact. He could not reasonably have been expected to anticipate the revolution in agricultural science that was later capacity of the limited supply of land to feed much enlarged populations. I improvements in the techniques of fertility limitation. Similarly, Malthus die opportunities offered by international trade for expanding a small island’s

subsistence to larger numbers. It was, in fact, through international specialization and trade that Britain first managed to evade the Malthusian danger in the nineteenth century.

These shortcomings are easy to identify a century and a half after Malthus wrote. But in his time there was no basis for a confident expectation that technology and trade could produce such a transformation. Indeed, it was then not inappropriate to sound warnings that mankind might be poised on the brink of disaster. After all, Britain, though it managed to escape the distresses of the positive checks, did not do so by a very comfortable margin. In Ireland they came into play with a vengeance; the potato famine of the 1840s reduced the population - through the combined effects of mortality and emigration - from nearly nine million to six and a half million in only six years.15

In Western countries, the tone of fatalism that ran through Malthus's discussion of the relationship between population growth and real wage changes now has no justification. The experience of the past century in industrial societies provides abundant evidence that the coefficients of human reproduction and food production are more variable than Malthus and many of his contemporaries believed them to be. In many of the poorer parts of the modern world, however, Malthusian presuppositions are dangerously approximated. Agrarian technology is backward and not readily responsive to stimuli for change, fertility is largely unchecked by modern contraceptive techniques, while mortality rates have been sharply reduced by public health and sanitation measures. In these areas Malthusian warnings have not lost their relevance. This issue is one of the central problems of our times.

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