Population & Urbanization

Demography: Demography is the science dealing with the size, distribution, composition, and changes in population. In other words, the subject which is concerned about the study of human populations is known as demography. Demography studies birth rates, death rates, migration, and the basic characteristics of the population that are influenced by the factors such as age structure and the racial and gender composition of populations. Demography also is concerned with population characteristics, such as marital status, that influence birth rates, death rates and migration.

The size, growth, and characteristics of all human populations are determined by three basic forces, referred to by sociologists as the three basic demographic variables. These variables are Fertility or birth rates, mortality or death rates; and migration.

Demography is the study of the statistical and mathematical study of the the size, composition, and spatial distribution of human populations, and of changes overtime in these aspects through the operation of the five processes of fertility, mortality, marriage, migration and social mobility. (Bouge, 1969: 1-2)

Theory of Malthus

In 1798 the English historian and political scientist Thomas Robert Malthus (1766-1834) first published his Essay on the principle of population. Many of the issues he raised are still being debated today. Malthus took an extremely pessimistic view, asserting that human populations tend to increase at a rapid rate than the food supply needed to sustain them. Human beings, malthus said confront two unchangeable and antagonistic natural laws: (1) the “need for food” and (2) the “passion between the sexes”. He contended that, whereas agricultural production tends to increase in a arithmetic fashion (1-2-3-4-5-), population has a tendency to increase in geometric fashion (1-2-4-8-16-32-). Based on this formulation, Malthus took a dim view of the future, for if populations always increase to the ultimate point of subsistence, progress can have no lasting effect. He considered famine, war, epidemic, draught, flood and pestilence to be the chief deterrents to excessive population growth. But Malthus also recognized that preventive checks might reduce the birth rate –what he called “moral restraint”. He viewed birth control as a sin and beneath human dignity.

Many questions have since been raised regarding the Malthusian thesis. For one thing, Malthus failed to appreciate the full possibilities of the industrial revolution and its ability to expand productive capacities to an extent unknown in his time. Moreover, Malthus did not foresee the possibility of new birth control methods or their application within the context of a value system favoring small families.

Theory of Marx

Marx insisted that an excess of population, or more particularly of the working class, depends on the availability of employment opportunities, not a fixed supply of food. Marks believed that a deepening crisis of the capitalist system would inevitably force increasing numbers of workers into the ranks of the unemployed, leading some individuals to include that society is overpopulated. Thus he traced the problems associated with population growth to capitalist society and sought cures in a fundamental restructuring of the social and economic order. Viewed in this fashion, population is always relative to the social structure. In sum, whereas Malthus looked primarily to the individual to restrain population growth through self-control, Marx looked to collective action to refashion institutional life.

Fertility:

The birthrate provides information on the actual reproductive patterns of a society. The birthrate (or, more specifically, the crude birth rate) is the number of live births per 1000 population in a given year. For example, in 1996, there were 15 live births per 1000 people in the United States.

One way demography can project future growth in a society is to make use of the total fertility rate (TFR). The average number of children that would be born alive to a woman during her lifetime, if she were to bear children at each age in accord with prevailing age-specific fertility rates. In other words, the TFR is the average number of children born alive to any women, assuming that she conforms to current fertility rates.

The general fertility rate (GFR) indicates the annual number of live births per 1000 women age 15 to 44.

Age-specific fertility rate (ASFR) means the number of live births per 1000 women in a specific age group, such as 25 to 29 or 30 to 34

Fecundity: The potential number of children that could be born if every women of child bearing age bore all children she possibly could is called fecundity.

Mortality:

Infant mortality rate: The number of deaths among infants under I year of age per thousand live births. Or we can say, the annual number of deaths of infants under one year of age per 1,000 live births.

Maternal mortality rate:

The annual number of deaths of women from pregnancy related causes per 100,000 live births.

Migration:

Migration rate: The net migration rate is the increase or decrease per 1,000 members of the population in a given year that results from people entering (immigrants) or leaving (emigrants) a society.

Growth rate:

The growth rate of a society is the difference between births and deaths, plus the difference between immigrants and emigrants per 1,000 populations.

Population pyramids:

The age and sex composition of a population can be portrayed by a population pyramid, often called the “tree of ages”.

Life expectancy at birth:

The number of years a new born infant would live if prevailing patterns of mortality at the time of its birth were to stay the same through its life.

Demographic Transition:

A number of social scientists have employed the idea of demographic transition to map out the population growth characteristic of the modern era. Viewed as theory, it has been used to predict what will happen in developing nations in the future. Demographic transition theory holds that the process of modernization is associated with three stages in population change.

Stage one: High potential growth. Societies untouched by Industrialization and urbanization are characterized by a high birth rate and a high death rate. As a result, the population remains relatively stable. The stage is described as having high potential growth because once the societies gain control over their death rates, their growth is likely to be rapid.

Stage Two: Transitional growth. Modernization has its initial impact on mortality levels. Improved housing, better levels of nutrition, and improvements in health and sanitary measures bring about a steady decline in death rates. Science a decisive reduction in the death rate has traditionally been associated with a marked drop in the infant mortality rate, a huge yearly crop of babies survives and in time themselves become parents. Thus a drop in the death rate, while the birth rate of a population remains unchanged, results in a marked in the rate of population growth. But as the time passes, couples began to realize that with lower infant mortality rates, fewer births are required to produce the same number of surviving children, and they adjust their families accordingly. Moreover, the costs and benefits associated with children change as modernization progresses, making small families economically advantageous. The second stage ends when the birth rate sinks to meet the death rate.

Stage three: Population stability. Modernization allows couples to gain control of their fertility through effective birth control techniques while simultaneously undermining proscriptions against their use. The result, according to demographic transition theorists, is that modern societies come to be characterized by low mortality and low fertility, a situation approximating zero population growth.

Phases of Demographic Transition:

No.	Phase	Birth Rates	Death Rates	Natural increase	Examples
1	High Stationary	High	High	Zero, or Very Low	Europe in the 14th century
2	Early expanding	High	Falling slowly	Slow	India before World war II
3	Late expanding	Falling	Falling faster than birth rates	Rapid	Southern & Eastern Europe before World war II India after World WarII+
4	Low stationary	Low	Low	Zero, or very Low	Australia, Newzealand, USA, in the1930’s
5	Declining	Low	Lower than birth rates	Negative	France before World war II East & West Germany in 1975*

Sources: Blaker, 1947; +Dyson, 1978; * Day, 1977.