The mathematical formulas regarding food supply and population growth are not correct. This criticism is beside the point because Malthus used the formulae only as examples to illustrate the dissimilar and unrelated nature of the growth of population and food supply.
2. The effects of additional population:
Malthus failed to consider that the additional increments of population are also capable of increasing production. “A baby comes to the world not only with a mouth and a stomach but also with a pair of hands.” Against this criticism it may be said that in agriculture the law of diminishing returns applies and the additional hands will produce less and less amounts of food in course of time.
For a time the tendency towards diminishing returns may be held in check by improvements in the arts of cultivation but diminishing rate of productivity is bound to operate sooner or later. The real basis of the Malthusian Theory is the Law of Diminishing Returns.
3. Import of food:
The economic history of the 19th and the 20th century shows that it is possible for an industrialised country to maintain a large population by importing food from outside in exchange of its industrial products.
The United Kingdom is the best example of such a situation. Many economists are, therefore, of the opinion that increase of population should be viewed not in relation to food supply but in relation to the total wealth of a country.
This is the basis of what is known as the Optimum Theory of Population. As Seligman puts it, “the problem of population is not one of mere size but of efficient production and equitable distribution”. This line of criticism, however, tacitly assumes that there is surplus food available in other countries of the world—an assumption which may not be true in the long run.
4. The effect of scientific advance:
Malthus took no account of scientific advance. During the 19th and the 20th century there was a tremendous increase of productivity in agriculture and industry. Scientific advance may in course of time render possible the production of food directly from inorganic matter, thus freeing human beings from the dependence on agriculture which is subject to the law of diminishing returns.
5. The effect of cultural advance:
Statistics show that cultural advance produces a decline in the birth rate. Spread of education leads to a higher standard of living and late marriages. In 19th century in Europe it was found that the birth rate was lowest where wages were highest.
In modern times people voluntarily adopt medical methods of control, which are cheap and readily available, rather than incurring possible loss of health and additional expenditure. In fact, some of the western countries are now faced with problem of declining population to such an extent that many people are talking of “race-suicide”.
In countries of Western Europe the bogey of Malthusianism has been overcome. The rate of population growth has fallen. Industrial and agricultural productivity has risen. Shortage of food is not a problem in these countries. But this is not true in the underdeveloped regions of the world like India and South East Asia. There is food shortage in all these areas and the rate of population growth is high.
Statistics show that the population of the world is increasing at fairly high rate. In 1800 the total world population was 919 million. In 1940 it was 2245 million and in 1970 it was 3632 million. World population in 1970 was nearly four times it was in 1800. J.E. Meade calculates that the world’s population in the year 2000 is likely to be three times what is was in 1950.
He also finds that at the present rate of growth of the world population (1.7% per annum) in 850 years the whole of the world’s land surface will be needed to provide standing room only to human beings.
The rate of growth of population in underdeveloped countries is higher than the world average. In 1991, the total population of India was 843, 387, and 888. In 2001 it is 1027, 015, 247. Between 1991 and 2001, population in India increased at the rate of 2.134% per annum.
Thus, the danger of over population is real, particularly in the underdeveloped countries. The planning authorities in such countries cannot afford to ignore the predictions of Malthus.
For a temporary period an increase of population in a country may enable it to secure better division of labour and greater efficiency of production. A more equitable distribution of the world’s wealth and income may similarly enable a country to support larger population for a time. But in the long run food deficiency is bound to occur unless, (i) scientific advance enables men to prepare food directly from the elements of (ii) an effective population control policy is applied simultaneously in all countries of the world.