Demographic theories : Biological , Cultural and Economic Theories.

Biological Theories
1. Malthusian Theory
2. Thomas Doubleday’s Diet Theory
3. Jouse De Castro’s Protein Consumption Theory:
4. Herbert Spencer’s Biological Theory:
Cultural Theories
1. Theory of Social Capillarity by Arsene Dumont
2. Theory of Increasing Prosperity by L. Brentano
3. Growth of Rationalism and Fertility Decline by Roderich von Ungern-Stenberg
Economic Theories
1. Leibenstein’s Motivational Theory of Population Growth
2. Theory of intergenerational wealth by J.C. Caldwell
3. theory of combining sociology and economics of fertility by R.A. Easterlin
4. Karl Marx’s Theory of Surplus Population

Biological Theories

1. Malthusian Theory

Thomas Malthus (1766–1834) was an English clergyman who made dire predictions about earth’s ability to sustain its growing population. According to Malthusian theory, three factors would control human population that exceeded the earth’s carrying capacity, or how many people can live in a given area considering the amount of available resources. Malthus identified these factors as war, famine, and disease (Malthus 1798). He termed them “positive checks” because they increase mortality rates, thus keeping the population in check. They are countered by “preventive checks,” which also control the population but by reducing fertility rates; preventive checks include birth control and celibacy. Thinking practically, Malthus saw that people could produce only so much food in a given year, yet the population was increasing at an exponential rate. Eventually, he thought people would run out of food and begin to starve. They would go to war over increasingly scarce resources and reduce the population to a manageable level, and then the cycle would begin anew.

Of course, this has not exactly happened. The human population has continued to grow well beyond Malthus’s predictions. So what happened? Why didn’t we die off? There are three reasons sociologists believe we are continuing to expand the population of our planet. First, technological increases in food production have increased both the amount and quality of calories we can produce per person. Second, human ingenuity has developed new medicine to curtail death from disease. Finally, the development and widespread use of contraception and other forms of family planning have decreased the speed at which our population increases. But what about the future? Some still believe Malthus was correct and that ample resources to support the earth’s population will soon run out.

2. Thomas Doubleday’s Diet Theory:

Thomas Doubleday, a social philosopher and an English economist, was born in 1790. He expressed his views regarding various natural laws which govern population. According to him, the rate of population increase will be less when the quantity of food supply is greater. It means that the increase in population and food supply are inversely related. Doubleday mentions two states of food supply, i.e., (i) The Plethoric state having good food supply where the fertility is low, and (ii) the Deplethoric state in which due to food shortage we find diminution of proper nourishment where the fertility is high.

According to Doubleday, fertility is affected by leanness in all plants and animals. An overfed plant can be revived only when the plants are depleted either by ringing the bark or by extreme lopping or the trenching of the roots. Besides, the sterility in plant life is possible when the application of fertilizers is excessive. He also believes that thin birds or animals give birth to more offspring, while bulky or fat birds or animals give birth to less. Similarly, this becomes true about trees and plants. It means that fertility depends on the fatness of living beings, according to Doubleday.

Moreover, Doubleday also observes that high fertility has been found in those persons who are vegetarians, or who eat more rice or whose staple diet is rich, whereas fertility will be low in non-vegetarian persons.

Doubleday divides society into three groups:

(1) The first group includes those who are in a state of affluence and are well supplied with luxuries. Their number is on constant decrease. While the number of those who are engaged in mental or physical activities and are living busy life, is on the increase.
(2) The second group consists of the poor people who have less supply of food. Their number is increasing rapidly. In other words, the constant increase in population is found in the group where people are worst supplied with food. This happens in all societies.
(3) The third group has those people who form the mean and median between two opposite states and who fall under the average income group and those who are tolerably well supplied with good food or who get a normal diet and do not overwork and yet are not idle. Their number is stationary.

Doubleday concludes that “it is upon the numerical proportion which these three states bear to each other in any society that increase or decrease on the whole depends.”

Doubleday is also of the view that, “The rich produce less children as the fertility would be less amongst them and therefore, the transfer of their wealth will be distributed among a few People. Over a period of time, it may happen that there is no one as an heir to that property and therefore this wealth will pass to the children of the poor. Again when the children become rich, they will restrict their families and their wealth will be gained once again by the poor. Thus socialism comes on its own through the automatic distribution of wealth by nature.”

Thomas Doubleday’s diet theory has been criticised on the following grounds:

1. Doubleday’s observation regarding an inverse relationship between food supply and fertility has no scientific basis.
2. According to Doubleday, the fertility is low in the Plethoric state due to good food supply and is high in Deplethoric state due to food shortages and diminution of proper nourishment. However, such things have not happened in reality. Even in Plethoric state the population goes on increasing.
3. Doubleday believes that the rich people have less children whereas the poor have more. In reality, this is far from true, because in many cases we find more children in rich families and less in the poor ones.
4. Doubleday opine that the number of those persons who get a normal diet and who come under the average income group remains stationary. But experiences has shown that even in such an income group the number has always been increasing.
5. Doubleday is of the view that fertility depends on fatness. As the rich persons are fat, fertility is low with the increase in fatness. In this regard, Spencer has criticised this presumption of Doubleday. According to him, in reality every rich person may not be always fat. Spencer felt that fatness does not fully depend on good food but the root cause of fatness is bad digestion. At present, the rich persons are more conscious about their health and their families and with the help of gyms and health clubs and medical facilities, they keep themselves away from fat and maintain health.
6. Doubleday is of the opinion that socialism will come on its own through the automatic distribution of wealth by nature. This argument does not have any scientific support of distribution of wealth and thus it cannot be said to be true.
7. In Doubleday’s diet theory there is confusion between fertility and fecundity. While criticising the theory of Doubleday, Thompson and Lewis have said that there is no scientific basis for the belief that the proportion of protein in the diet or the relative abundance of intake of calorie has any noticeable effect upon fecundity. The actual bearing of living children, that is fertility of any population, may be affected substantially by the use of contraceptives as preventive checks while fecundity remains unchanged.

3. Jouse De Castro’s Protein Consumption Theory:

Jouse De Castro expressed his views in his famous book The Geography of Hunger regarding the correlation between the fertility and the consumption of protein. Castro accepted the findings of R.J. Solankar who conducted experiments on rats in 1920. In these experiments Solankar found that with the increase in protein consumption in diet, the fecundity will decrease and it will increase with low protein content in diet.

His experiment led to the following conclusions:

(i) When 10 per cent protein was given to a female rat, per mated female rat gave 23.3 births;
(ii) When 18 percent protein was given to each female rat, per mated female rat gave 17.4 births; and
(iii) When the quantity of protein was increased to a level of 22 percent to each female rat, the birth per mated female rat reduced to 13.8 births.

Through these experiments Castro came to the conclusion that the fatness is affected by the consumption of protein. The fatness increases with the protein rich diet, which leads to lower fertility. This concept of Castro is similar to the Doubleday’s diet theory that the rate of population increase is influenced by food supply.

Moreover, Castro also found a direct relation between the functioning of the liver and that of the ovaries. In the words of Castro, “It is known that there is a direct connection between the functioning of the liver and the ovaries, the role of the liver being to inactivate the excess estrogens which the ovaries throw into the blood stream. Fatty degeneration of the liver and the tendency to cirrhosis are some of the characteristic result of protein deficiency when degeneration of the liver occurs, it begins to operate less efficiently, and is less effective at its job of inactivating excess oestrogents. The result is a marked increase in the women’s reproductive capacity.”

According to Castro, balanced food is not available to the poor and therefore poor people are always getting less protein in food which results in sluggish liver function. Consequently, when males have defective liver, the estrogens in women’s body cannot be neutralised, and with the increase in estrogens the women’s reproductive capacity increases. This results in high birth rate. Therefore, compared to the rich, the birth rate in the poor people with chronic hunger (malnutrition) is high. But in the case of acute hunger, sexual activity goes down. According to Castro, people or societies are blamed for the high birth rate in the poor countries, which is not proper. For this the rich countries or the people of affluent societies should be blamed, because the imperial or colonial powers have not taken any steps to improve the standard of living of their people nor have they made attempts to provide good food. On the contrary, instead of concentrating more on the increase of food production, imperial powers have concentrated on the purchase of raw materials and food supplies at low rates and finished products have been sold out at high rates in their colonies.

As a result, due to high prices and low wages, the people’s food intake becomes imbalanced and they cannot get enough protein content in their diet. With the reduction or absence of protein contents in their food, the capacity to produce more children increases which ultimately results in the increase in poverty. When poverty increases, again due to the imbalanced food, people get less protein, which again leads to the increase in the capacity to produce more children. Such a vicious cycle goes on. It was painful for Castro when he observed that adequate attention had not been given to the problems of the imbalance food by the rich, the capitalists, the scientists or the imperialists. They had given importance only to the commercial activities rather than to the social aspects of poverty.

Castro reflected on the issue with reference to India that out of the total number of children born in India, almost fifty percent suffer from starvation and die before they reach the age of marriage. On the basis of data for different countries relating to the association of fertility with consumption of protein, Castro concluded that in 1952 two-third of the world population experienced chronic hunger, i.e., malnutrition, disease or early death.

According to him, the fertility rates can be reduced only if more attention is paid to grow more food crops than commercial crops which are made available to the poor people. In the words of Castro, “when deserts of ice and impenetrable jungles are being turned to gardens and orchards, when the lands we farm and the plants we grow are being made to multiply their field, and while we are barely learning how to tap the great food reservoirs of water, the wild flora and of artificial synthesis, the Malthusians go on setting up their sinister scarecrows. It is nothing to us, since we have reasons to fear them.”

Castro pointed out that to eradicate chronic hunger, priority should be given to the problem of balanced food. Efforts should be made to bring more lands under the plough with improved farming methods and extensive cultivation. This is only possible through economic development leading to rising income of the poor which increases their protein consumption.

Criticisms of Jouse De Castro’s Protein Consumption Theory:

1. High fertility has been experienced in many developed countries with the increase of protein in diet.
2. Scientifically, it cannot be proved that protein rich diet leads to lower fertility.
3. Fertility always does not increase in poor people because it is not true that chronic hunger will always give more importance to sex.
4. In poor countries, the reasons for high birth rate are poverty and imbalanced food. However, factors like agriculture based economy, social, religious or cultural structure of the society, education, existence of joint family system, marriage at early age, etc. cannot be ignored in influencing population growth.
5. Economists do not accept the view that human fertility depends on diet alone. According to Coontz, fluctuations in fertility during trade cycle cannot be explained in terms of diet.
6. Castro’s view that with economic development fertility can decline has been criticised by Leibenstein. According to him, “The reasons why this approach is fallacious is that the economy might not have experienced sustained development if fertility rates had not declined at some crucial stage during the expansion.”
7. Thomson and Lewis have critcised Castro for the relation between diet and fecundity. According to them, there is no scientific basis for the belief that good diet or relative abundance of calorie intake have any noticeable effect upon fecundity. Rather, fertility may be affected by the preventive checks of various kinds, while fecundity remains unchanged.”

4. Michael Thomas Sadler’s Destiny Theory:

Michael Thomas Sadler, an Economist and a British social reformer, was born in 1780. He was a contemporary of Malthus. He expressed his ideas about population in his book The Law of Population. According to Sadler, the law which regulates the growth of animals and plants is primarily the same as the law which regulates the growth of human population.

He was of the opinion that “The fecundity of human beings is in the inverse ratio of the condensation of their numbers.” Moreover, the fertility rate decreases with the increase in the density of population. In the agriculture based or pastoral countries where the density of population is low, the fertility rate of the population becomes high. In such countries, people have the capacity to work hard and hardworking people give birth to more children. With the passing of time, when there is industrialisation and the population becomes more civilized and literate, the density of population increases. Here people would limit the size of family and in such socio-economic conditions they will be happier and there will be prosperity.

Sadler was a great critic of Malthus. He did not accept Malthus’s view that population increases in geometrical progression and food supply increases in arithmetical progression. According to Sadler, such increase of population and food supply in mathematical terms just cannot happen, because when population increases density too will increase. And when density increases, the capacity to produce children goes down and thus with the increase in density, the fertility rate declines. He believed that population adjusts itself with the times.

He did not accept the fear of Malthus that positive checks by nature take place with the growth of population. He also did not believe in the preventive measures of birth control described by Malthus. Sadler was very optimistic and he tried to establish a link between population and food supply.

He was of the view that if the fertility rate of population increases, people will be able to produce food according to their needs and the food supply and population will get adjusted to each other. Sadler also believed that when the density of population increases the unhealthy atmosphere also increases which leads to the increase in the death rate. Further, if the death rate is high, it will lead to increase in the birth rate. This happens to compensate for the loss of population. And if the death rate is low, the birth rate also goes down.

Criticisms of Michael Thomas Sadler’s Destiny Theory:

If we compare Sadler’s theory to the Malthusian theory of population, it can be said that the theory of Sadler is very optimistic. When Sadler’s book was published in 1830, many economists, sociologists and demographers were under the spell of pessimism created by Malthus in his population theory. In such an atmosphere to give optimistic thoughts itself was a great achievement.

But the theory of Sadler is also criticised on different grounds:

1. Sadler failed to distinguish between fecundity and fertility. He said that the fecundity of human beings is in the inverse ratio of the condensation of their numbers. But in fact no biological reason is found to prove the idea that if density brings down ‘fertility’, it will bring down ‘fecundity’ also. This is because in slums the density is very high and at the same time fertility is also high among slum dwellers.
2. Moreover, in many countries of the world where the density is high, the fertility rate is also high. Even in India, in some states like Delhi, Kerala and West Bengal where the density is high, the fertility is not low in comparison with the fertility of other states.
3. Another point of criticism is the paradoxical statement of Sadler that with the increase in density, the fertility rate decreases. At the same time, he was of the view that with the increase in density the death rate will increase and consequently, to compensate for the loss of population the fertility rate also increases.
It means that the fertility rate will not decrease, but it will increase with the increase of density. Thus, Sadler’s statements are self-contradictory.
4. Sadler’s view that with industrialization the population decreases has not been proved true. In a country like India, industrialisation has not led to the decline in the growth of population.

5. Herbert Spencer’s Biological Theory:

Herbert Spencer, a famous English philosopher and sociologist, propounded the biological theory of population in his book The Principles of Biology. Spencer argued that fecundity decreases when the complexity of life increases. According to him, changes in the growth of population occur due to natural change in the reproductive capacity of human beings. Therefore, his theory has been known as a natural theory of population which is similar to the theory of Sadler and Doubleday. Spencer believed that “there exists antagonism between individuation (survival) and genesis (reproduction)”. When any individual does hard work for his personal development at his work place, the desire for reproduction decreases. In other words, when more energy has been utilised for one’s self-development, the energy available for reproduction will be less and consequently the population growth will be less. Thus, with the development of society and for one’s success and survival (individuation), life becomes more complex which results in reduction in the capacity of reproduction. This is observed from the fact that fertility is more in rural individuals whose life is not complex, whereas fertility is low in an industrial society where life is more complex, the pressure of education is more and the brains are overtaxing.

We have four different situations which explain the relation between individuation and genesis:

(i) The individuation will automatically below when there is high genesis. This situation we find among the poor.
(ii) The genesis will be low when there is high individuation. Such a situation we find among the rich.
(iii) The individuation will improve when the genesis is low.
(iv) The genesis will be high when the individuation is low. In poor people, we find less individuation and more genesis.

Moreover, because of high fertility the individuation will be low and therefore the death rate will increase. At the same time because of low individuation, the expectancy of life will also decrease. To Spencer, the expectancy of life can be increased, when the birth rate decreases. Spencer’s theory of population is based on the theory of evolution. According to Spencer, the fertility rate is higher in small creatures. In the words of Spencer, “The minutest organisms multiply asexually (without sex) in their millions.” Many small cells do not reach the maturity period. If this happens and small cells grow in number twice or thrice, population will rapidly increase and multiply itself. Small compound cells get increased in thousands, while big compound cells in hundreds and still bigger cells lose their productive capacity. In the same manner, Spencer explained the fertility of human beings.

According to him, people can be divided in three groups:

(i) Poor people who live a simple life whose fertility is high;
(ii) Middle class people whose fertility is correspondingly low; and
(iii) People who live developed or complex life whose fertility is fairly low.

According to Spencer, in societies where people, especially woman, are educated and belong to rich families, their reproductive power is low, as compared to the poor who are uneducated and whose reproductive power is high. In the words of Spencer, “In its full sense, the reproductive power means the power to bear a well-developed infant, and to supply that infant with the natural food for the natural period. Most of the flat chested girls who survive their high- pressure education are incompetent to do this. Were their fertility measured by the number of children they could rear without artificial aid, they would prove relatively very infertile.” Spencer believed that if population increases we get more manpower through which natural resources can be exploited and the socio-economic and cultural standards of the people can be raised. Thus, he was of the opinion that increase in population was beneficial rather then harmful.

Further, as per Spencer, a determining factor for birth fate and death rate is longevity. The expectancy of life increases and the death rate decreases when life becomes more complex. He, therefore, suggested increase in life expectancy in order to reduce the birth rate.

Criticisms of Herbert Spencer’s Biological Theory:

1. Spencer’s population theory is not a real theory but a biological theory.
2. The view of Spencer that fertility decreases due to more complex life has no empirical evidence. There is high fertility rate even in rich families or industrialised societies where people’s life is more complex.
3. The problem of population growth itself is a complex phenomenon and therefore it cannot be explained as a biological one.
4. Spencer’s view that educated women whose individuation is high would prove relatively infertile, is not realistic. Even educated women have high reproductive power.
5. Spencer’s theory that fertility is affected by the natural process of individuation has no justification because when Spencer propounded this theory the birth rate was high in the western countries.

Cultural Theories:

Under the cultural theories, we include those explanations which view fertility differentials in terms of factors, both material and non-material, that form part of our cultural milieu. In particular, such theories emphasize mainly the psychological attributes of individuals, which, in turn, are the product of prevailing culture. Though, economic considerations are often included in the explanation, they are treated just one of the several factors affecting psychological attributes.

Theory of Social Capillarity:

In 1890, Arsene Dumont, a French scholar, propounded the theory of ‘social capillarity’. According to Dumont, in a civilized community, the principle of social capillarity governs the fertility behaviour of population. This principle is based on the recognition that every society is marked with a set of hierarchic social order in which individuals in the upper hierarchy enjoy greater prestige than those belonging to the lower hierarchy.

There is a constant effort on the part of the individuals to rise in the hierarchy of social status. A large family is said to be an obstacle in the process of upward social mobility. Dumont, thus, attributed fertility differences among different people to the will of moving up in the social order, i.e., social capillarity. This aspiration or will to advance up in the hierarchy of social status is different from the desire to dominate others by power politics or wealth.

Although the principle of social capillarity is manifest in all the societies, it operates more efficiently in communities characterized by great social mobility. On the other hand, in a society where status and caste are rigid factors, social capillarity is very weak. Dumont maintained that poverty is not the cause of high fertility. Citing demographic data from France, he argued that the regions of high fertility are precisely those that are remote from urban centres and are marked with ignorance and poverty.

Likewise, he argues that wealth is not the cause of low fertility, for both wealth and low fertility are common products of the will to advance up in the social hierarchy. He claimed that the principle of social capillarity explains fertility differentials not only within a country but also among different countries.

The principle of social capillarity was the first logical attempt of providing an explanation of fertility transition. It had profound influences on the later writings. For instance, Kingslay Davis’ theory of change and response concerning fertility also acknowledges the role of the desire to rise in the social scale in declining fertility.

The principle holds good even today in explaining the intra- and inter-country differentials in fertility levels. The theory of social capillarity, however, attracted criticism, as it was not backed by sound statistical proof. Nevertheless, credit must go to Dumont for underscoring the need of investigating the psychological attributes of individuals in its social context while explaining the fertility levels.

Theory of Increasing Prosperity:

In 1910, L. Brentano presented another explanation of fertility differentials in his theory of increasing prosperity. According to Brentano, the key to fertility differences is rooted in the differences in material prosperity of different peoples. He argues that man is essentially a creature of pleasure, the sources of which vary from group to group. The poor with an extremely restricted number of alternative pleasures tend to find compensation of this deprivation in sexual indulgence.

This explains high fertility level among them. On the other hand, the wealthy have a large number of competing pleasures, and in general, their gratification is found outside home. Brentano suggested that a general decline in fertility levels is the function of technical, scientific, industrial and commercial progress which makes more and more sources of pleasure available to a growing number of people.

In order to avail themselves of the facilities of pleasure people must have material means at their disposal. They have to make choice between family size and opportunities of pleasure. It should, however, be noted that according to Brentano, decline in birth rate with increasing prosperity “does not imply an increase in sexual continence”.

Brentano has not been successful in differentiating between sexual enjoyment and pleasure of parenthood. For the poor, sexual indulgence is identical with the desire of offspring, whereas for the rich the same is not true. Brentano’s arguments imply that sexual indulgence is the main pleasure for the poor and lack of information about contraceptive measure leads to high birth rate. But ignorance rather than pleasure then appears to be the main determinant of fertility levels among the poor. On the other hand, among the rich since there is no increase in ‘sexual continence’, the choice is between parenthood and alternative pleasure.

Growth of Rationalism and Fertility Decline:

Roderich von Ungern-Stenberg, in his book, The Causes of the Decline in the Birth Rate within the European Sphere of Civilization, published in 1931, argued that increasing prosperity is not the cause but the goal, and birth control is the means for attaining this goal. He also denies that fertility decline is the result of changing age structure of population, or decline in the marriage frequency, or decline in infant mortality rates.

A generally lower birth rate in the urban centres does not imply a causative association between urbanization and fertility decline either. In fact, both urbanization and decline in fertility are the results of a common cause, i.e., the development of capitalist mentality which denotes a ‘rationalistic’ conception of life in which people weigh all actions carefully including paternity. Ungern-Stenberg made this proposition on the basis of the experience of European countries where capitalist mentality has permeated all classes of the society.

Economic Theories:

The economic theories are based on the assumption that fertility behaviour of couples in a population is based on mainly economic considerations. They are, therefore, built within the micro- economic framework. The economic explanations of fertility were developed mostly during the second half of the twentieth century. The theories propounded by Harvey Liebenstein, Richard A. Easterlin and J.C. Caldwell are important in this regard.

Leibenstein’s Motivational Theory of Population Growth

Incorporating the cost-benefit analysis of children in his theory, Harvey Liebenstein, in 1953, proposed that the fertility decision of a couple is based on the balance between utility and disutility of an additional child. According to Liebenstein, there are three types of utilities of an additional child, viz., as a ‘consumption good’ where a child is considered as a source of pleasure for the parents; as a ‘productive unit’ where a child is expected to contribute to the family income after he enters into the labour force; and as a ‘source of security’ for the parents in their old age. On the other hand, the disutility refers to the direct and indirect costs involved in having an additional child. While the direct costs relate to the conventional expenses involved in the bringing up, the indirect costs are the opportunities, measured in economic terms, foregone in the event of an additional child.

Liebenstein states that a couple makes a ‘rough calculation’ regarding the balance between the utilities and disutility’s before deciding for an additional child. It should be noted here that Liebenstein’s emphasis is mainly on the higher order births. Liebenstein mentioned that the concept of ‘utility and disutility’ is dynamic and is governed by the overall levels of development of the society. The process of economic development operates through income effects, survival effects and occupational distribution effects.

The dynamic relationship between economic development and utilities and cost of an additional child is shown in Figure 8.4. It is evident from the figure that with rising income levels, while the ‘consumption utility’ remains unchanged, the other two forms of utilities undergo sharp decline. The costs involved in bringing up the additional child, on the contrary, report a constant rise. On the basis of this, Liebenstein maintained that as economic conditions improve, the number of high parity children for the representative family has a tendency to decline.

It may, however, be noted that Liebenstein’s theory has more of an explanatory value than predictive one. In an almost identical way, Gary S. Becker, in his paper entitled An Economic Analysis of Fertility published in 1960, proposed that the micro consumption theory in economics is applicable to fertility also. According to him, variations in completed fertility can be understood within the framework used by economists in the analysis of demands of ‘durable goods’. Just as a consumer with a given taste makes a decision to purchase durable goods after a careful evaluation of its utilities and costs, the household choice of fertility is made after considering the utilities vis-a-vis monetary and opportunity cost of the additional child. Thus, according to Becker’s theory, both children and household durable goods are identical.

Becker’s economic theory of fertility was based on two traditional economic postulates: first, the household behaviour is rational on the basis of changing taste and second, and the prices of commodities desired by the representative households remain indifferent to the households’ consumption decisions. According to Becker, knowledge about family planning measures is an important factor determining fertility behaviour.

He argued that with a uniform knowledge across different income groups there will be a positive association between income and fertility levels because higher income will enable couples to have more number of children. He attributed the observed inverse relationship between income and fertility levels to differential knowledge of family planning measures in different income groups. He stressed that once the knowledge of birth control measures is evenly spread, a positive association is bound to emerge between fertility and income.

Becker’s economic explanations of fertility and income attracted severe criticism later. While some scholars argued that the ‘consumer durable’ model is not applicable to children and that it cannot predict fertility differentials by income, others, including Easterlin, have argued that tastes cannot be taken as immutable facts, and insisted that tastes change systematically according to one’s upbringing.

Theory of intergenerational wealth by J.C. Caldwell

J.C. Caldwell propounded the theory of intergenerational wealth flow to explain the fertility behaviour of people. He argued that the fertility decision of people in any society is rational and is based on the economic worth of the children. He suggested that fertility levels in a society are high if children are economically useful to parents, and on the other hand, low if the children are economic burden for their parents. In other words, if the flow of wealth is from younger generation to older ones, fertility levels tend to be high. On the contrary, flow of wealth in the opposite direction, i.e., from parents to children, results in low fertility levels.

Thus, according to Caldwell, it is the direction of intergenerational flow of wealth in terms of goods and services that determines the fertility levels in any society. In all primitive and traditional societies children are useful to parents in several ways, and the flow of wealth in such societies is from younger generation to older generation. A high fertility among such people is, therefore, economically rational. As against this, in the modern societies, children are economic liability on parents, and wealth flows from parents to children. This explains a low fertility in such societies.

According to Caldwell, a reversal in the direction of flow of wealth is a precondition for any decline in fertility levels. This reversal necessitates emotional and economic nucleation of family. In many developing countries this nucleation of family has already begun under the influence of westernization. Caldwell is of the opinion that further strengthening of this process will bring down the birth rates in the less developed parts of the world thus bringing down overall growth in population in coming decades.

Theory of combining sociology and economics of fertility by R.A. Easterlin

R.A. Easterlin provided a more comprehensive theory combining sociology and economics of fertility (Bhende and Kanitkar, 2001:321). He has explained the link between fertility transition and modernization. Easterlin has defined the process of modernization as “transformation in economic, social and political organization and in human personality” (Easterlin, 1983:563). He argues that although fertility transition has accompanied the process of modernization, the specific links between the two are not clear.

According to him, modernization influences fertility only indirectly. Bongaarts had earlier talked about a set of ‘proximate determinants’ through which ‘modernization’ acts upon fertility levels (Bongaarts, 1978:106). These proximate determinants include, for instance, deliberate fertility control, postpartum in-fecundability, waiting time to conception etc. among others. Easterlin has further added a set of ‘intervening variables’ between modernizations and ‘proximate variables’.

These intervening variables are the demand of children, supply of children and costs involved in fertility regulations. While the demand of children refers to the number of surviving children a couple would want if fertility regulations were costless, supply of children is the number of surviving children a couple would have if fertility is not deliberately controlled. The costs of fertility regulations involve both objective and economic costs.

Thus, in Easterlin’s opinion, the process of modernization directly influences demand, supply and regulation costs, which, in turn, determine the deliberate control. And finally, deliberate measures of fertility control in conjunction with other proximate determinants shape the observed fertility levels in a society.

In a pre-modern society the demand for children is greater because of the nature of the economy and adverse mortality conditions. The individual couples in such societies, however, cannot produce as many children as they want, and demand for children, thus, exceeds supply. In such circumstances, the couples tend to have as many children as possible. In other words, the observed fertility is identical to natural fertility. In due course of time, the process of modernization sets in and improving mortality conditions increase the potential supply of children. The regulation costs begin to decline along with a corresponding decline in the demand for children. Since the society lacks deliberate attempts to limit family size, the couples now have more children than they want.

Thus emerges the situation of an excess of supply over demand that generates motivation for family size limitation. The couples then weigh the disadvantages of excess supply against the regulation costs. In the initial stage, since fertility regulation costs are high, natural fertility continues to prevail. As modernization proceeds, the excess supply over demand further grows and motivation for fertility control becomes still stronger.

Since regulation costs have also undergone decline, the motivation for family size control is strong enough to offset the former. The couples begin to take deliberate actions to control fertility, and actual family size falls below potential supply though still exceeding demand. Eventually, in the subsequent stages, as motivation grows further stronger and regulation costs lower, a point is reached when actual family size corresponds to demand.

Easterlin’s analysis has been summarized in Figure 8.5 Modernization has been presented along the horizontal axis, while supply and demand, measured according to the number of surviving children per married woman have been shown along the vertical axis. As seen, in the initial stage demand for children (Cd) exceeds supply (Cn) and actual family size (C) is equal to supply. As modernization occurs, a stage is reached (point m) when supply becomes greater than demand generating motivation for controlling family size.

As the motivation is not strong enough to offset regulation costs in the initial stages, actual family size continues to correspond to supply. However, with the further inroads of modernization, motivation becomes stronger and deliberate controls set in (point h) resulting in decline in family size. The process continues and eventually, a point is reached when actual family size falls to a level corresponding to demand (point p).

Karl Marx’s Theory of Surplus Population:

Karl Marx, the famous author of Das Kapital, did not propound any specific theory of population like Malthus. However, he rejected the Malthusian theory as completely imaginary and false. He did not accept Malthus’s view that population increases in geometrical progression and means of subsistence in arithmetical progression. Marx’s views about population growth are based on his theory of surplus value. According to him, the problem of population arises only in a capitalist society which fails to provide jobs to all workers because the supply of labour is more than its demand. As a result, there is surplus population. But there is no surplus population in a socialist society where the means of production are in the hands of workers. All able bodied workers are employed and there is no surplus labour. So there is no need to check the growth of population in a socialist country.

Capitalism, according to Marx, is divided into two classes – the workers who sell their ‘labour-power’, and the capitalist who own the ‘means of production’ (factories). Labour-power is like any other commodity. The labourer sells his labour for its value. And its value, like the value of any other commodity is the amount of labour that is required to produce labour-power. In other words, the value of labour-power is the value of the means of subsistence (i.e., food, clothing, housing, etc.) necessary for the maintenance of the labourer. This is determined by the number of hours necessary for its production. But the value of commodities necessary for the subsistence of the labourer is never equal to the value of the produce that labourer produces. If a labourer works for ten hours a day, but it takes him six hours’ labour to produce goods to cover his subsistence, he will be paid wages equal to 6 hours’ labour. The difference worth 4 hours’ labour goes into the capitalist pocket in the form of profit. Marx calls this unpaid work “surplus value”.

According to Marx, this surplus value leads to capital accumulation. The capitalist’s main aim is to increase the surplus value in order to increase his profit. He does so by “the speeding up of labour”, which means increasing the productivity of labour. When the productivity of labour increases, the labourer produces the same commodity in less hours, say 4 hours, or he produces more (two) commodities, say in 6 hours. This raises the surplus value and hence the capitalist’s profit.

The increase in the productivity of labour requires a technological change that help in increasing total output and lowering the cost of production. He introduces labour-saving machines which increase labour productivity. This process of replacing labour by machines creates an industrial reserve army which increases as capitatism develops. The industrial reserve army is the surplus population. The larger the industrial reserve army, the larger the surplus population and the worse are the conditions of the employed labourers. This is because the capitalists can dismiss dissatisfied and troublesome workers and replace them from the ranks of the reserve army. Capitalists are also able to cut down wages to a semi-starvation level and raise more surplus value, while the surplus population increases.

Marx’s theory of surplus population has been criticised on the following grounds:

(1) Unrealistic Theory: The Marxian theory is unrealistic because it is based on the theory of surplus value. The concept of surplus value has not been accepted even in socialist countries since it is unrealistic. Therefore, the very basis of his population theory does not exist.
(2) Not Applicable to Socialist Countries: Marx’s contention that there is no population problem in a socialist country has been proved wrong. China, the largest socialist country of the world, has been faced with the problem of population growth. It has been trying to control it by adopting “one-child” norm.
(3) Technological Progress reduces Industrial Reserve Army: According to Marx, with increasing technical progress the industrial reserve army expands which, in turn, leads to surplus population. This is an exaggerated view because the long run effect of technical progress is to provide more employment.
(4) No Explanation of Determinants: Marx does not explain the determinants of population growth like birth rate, death rate, migration, etc.

Thus Marx’s explanation of population growth is not a theory in the true sense but simply a view.