இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.
population
Population
Terms related to population
Population: A group of individuals of the same species occupying a particular geographic
area.
People: The members of a particular nation, community, or ethnic group.
Crude Birth rate (Natality Rate): Number of live births per thousand people in a year.
Crude Death Rate (Mortality Rate): Number of deaths per thousand people in a year.
Net Migration Rate:
Formula for Net Migration Rate:
N = 1000 ×
N = Net migration rate
E = Number of people emigrating out of the country
I = Number of people immigrating into the country
P = Estimated mid-year population
Fertility Rate: Number of live births expected per 1000 women in their lifetimes in a
specified geographic area and for a specific point in time, usually a calendar year.
Niger has the highest fertility rate of 6.49, while Singapore has the lowest fertility rate of
0.83.
Dependency ratio: Number of dependents in a population divided by the number of
working-age people.
Dependents are those who are below 15 years and above 65 years, while working age
population are those population who are aged between 15 and 64 years.
Growth Rate: = (CBR – CDR +/- Net Migration Rate) / 1000
South Sudan has the highest population growth rate of 3.83% in 2017.
Rate of Natural Increase (RNI) = CBR – CDR (No Migration); CBR > CDR = ↑ population
RNI is usually expressed in terms of percentage.
E.g., 2% = 2/100 = 20/1000 RNI ≠ population growth if migration significant.
Adult Literacy Rate: The Adult literacy index (ALI) is a statistical measure used to determine
how many adults can read and write in a certain area or nation.
Adult literacy is one of the factors for measuring the Human Development Index (HDI) of
each nation, along with life expectancy, education, and standard of living.
Burkina Faso has the lowest literacy rate of 21.8% (2015).
Life expectancy rate: Life expectancy equals the average number of years, a person born in
a given country is expected to live.
As of 2015, the country with the highest life expectancy is Monaco with 89.52 years; the
country with the lowest is Chad with 49.81 years.
World Population Milestones
According to the United Nations, population reached 6 billion on 12 October 1999
(celebrated as the Day of 6 Billion).
The world population reached 7 Billion on 31 October 2011. The current world population is
7.7 billion as of Feb 2019 according to the most recent United Nations estimates. The
United Nations projects world population to reach 8 billion in 2023 and 10 billion in the
year 2056.
Population Concepts
Overpopulation: A Situation whereby the population is considered too large for the
available resources.
Under–population: A situation where the population is less than the available resources of
a country.
Optimum – population: A situation where the number of people that can be supported is
the same as the available resources.
India – Population
The current population of India is 1,363,413,725 as of 19 February 2019, based on the latest
United Nations estimates.
India’s population is 17.74% of the total world population.
India ranks number 2 in the list of countries (and dependencies) by population.
The population density in India is 382 per .
33.6 % of the population is urban (460,249,853 people in 2019).
Age – Sex pyramids
There are three types of Age – Sex pyramids: expansive, constrictive, and stationary.
Expansive Age – Sex pyramids
These depict populations that have a larger percentage of people in younger age
groups.
Populations with this shape usually have high fertility rates with lower life expectancies.
Many least developed have expansive age – sex pyramids. Such a population pyramid is
a characteristic of newly developing countries such as Afghanistan, Bangladesh,
Kenya, and some countries of Latin America.
Constrictive Age – Sex pyramids
These are named so because they are constricted at the bottom.
There is a lower percentage of younger people.
Constrictive Age – Sex pyramids show declining birth rates, since each succeeding age
group is getting smaller and smaller.
The United States has a constrictive Age – Sex pyramid.
Stationary Age – Sex pyramids
This shows an equal proportion of the population in each age group. There is not a
decrease or increase in population; it is stable.
Austria has a stationary Age – Sex pyramid.
Population Theories
Malthusian Theory of Population
The Malthusian theory of population is the most well-known theory on population in
economics.
Malthus pointed out that an accelerated increase in population would outweigh the
increase in food production.
This would have an adverse impact on the development of an economy.
This theory is explained in the following propositions:
The rate of growth of the population is limited by the availability of the means of
subsistence i.e., food. If the means of subsistence increase, the population also
increases unless it is checked.
Population increases at a faster rate than food production. In other words, while the
population increases in a geometric progression, food production increases in an
arithmetic progression.
The preventive and positive checks are the two measures to keep the population on the
level with the available means of subsistence.
The first proposition states that the size of the population is determined by the availability
of food production.
In other words, greater production can sustain a larger population.
If food production does not increase to match the rate of growth of population, it will lead
to poverty.
The want of food would result in deaths and thereby automatically limit the population.
If the food production increases, the people will tend to increase their family size.
This will lead to more demand for food, so the availability of food per person will diminish.
This will lead to a lower standard of living.
The second proposition states that the population would increase at a geometrical
progression i.e., in the ratio of 2, 4, 8, 16, 32, etc., but food production would increase
at an arithmetical progression i.e., in the order of 2, 4, 6, 8, 10, etc.
If population increases there will be a burden on land, which is limited; as a result there will
be diminishing returns.
This will lead to a decrease in the output per worker and a corresponding decrease in the
availability of food per person.
The imbalance between the population growth and food supply would lead to a bare
subsistence of living, misery, and poverty.
This imbalance is corrected by two checks, namely preventive checks and positive checks.
Preventive checks are those checks applied by man to reduce the population. The
preventive checks include late marriage, self-restraint and other similar measures
applied by people to limit the family.
Positive checks affect population growth by increasing the death rate. The positive
checks on population are many and include every cause, either from vice or misery
which helps to shorten the life span. Common diseases, plagues, wars, famines,
unwholesome occupations, excess labour, exposure to the seasons, extreme
poverty, bad nursing of children are a few examples for positive checks.
Malthus thus recommended that the preventive checks can be used by mankind to avoid
misery or else the positive checks would come into operation.
As a result, there will be a balance between population and food production.
The Theory of Optimum Population
The modern theory of optimum population brings out the relationship between changes in
population and the consequent changes in per capita income.
Modern economists such as Sidgwick, Cannon, Dalton, and Robbins have propagated this
theory.
Optimum population means the ideal population relative to the natural resources, stock of
capital equipment and state of technology.
There will be an ideal size of the population at which per capita output (or real income per
head) will be the highest.
In other words, the optimum population is that level of population at which per capita
output is the highest.
A country is said to be underpopulated if the population is less than the optimum and
overpopulated if the population is more than the optimum.
Illustration
Let us assume that the availability of natural resources, capital equipment and state of
technology remain fixed in a country.
The population is assumed to be small relative to these resources.
When population increases, the labour force in a country also increases.
As additional labour is combined with fixed amounts of these resources, the per capita
output will initially rise due to greater specialisation and more efficient use of natural
and capital resources available.
As population increases, a point will be reached when capital and natural resources will be
fully exploited and output will be the highest.
Thus, the level of population at which the per capita output is the highest is known as
optimum population.
Beyond this point, if the population increases, the country will become overpopulated and
the per capita output will start decreasing because there are more women/men in
relation to natural resources in the economy.
Thus, the given amount of capital and natural resources have to be shared among a larger
number of workers resulting in smaller amount of equipment, materials and natural
resources available per person to work with.
Thus, the average productivity declines.
With the fall in the output per head, per capita income and standard of living of the people
also decline.
Overpopulation leads to a low standard of living, disguised unemployment and food
shortage.
Both underpopulation and overpopulation have shortcomings.
It is optimum population with the highest per capita output which is best suited for a
country.
The Theory of Demographic Transition
The demographic transition brings out the relationship between fertility and motility, i.e.,
between the birth rate and the death rate.
Birth rate refers to the number of births occurring per 1000 in a year.
Death rate refers to the number of deaths occurring per 1000 in a year.
This theory explains the changes in these rates as a consequence of economic development.
This theory points out that there are three distinct stages of population growth.
Stage I: High Birth Rate and Death Rate
In the first stage, the country is backward and less developed.
Agriculture will be the main occupation of the people, and primitive mode of cultivation will
be used.
The standard of living of the people will be low.
This stage is characterised by high birth rate and high death rate.
The high death rate is due to poor diets, improper sanitation, and lack of proper medical
facilities.
Birth rate is high on account of widespread illiteracy, ignorance of family planning
techniques, early marriages, social beliefs, customs, and attitudes of the people.
In this stage, the rate of growth of population is not high since high birth rate is offset by
the high death rate and the population growth stagnates.
Stage II: High Birth Rate and Low Death Rate
As a country advances, it might result in increase in industrial activity, creating more
employment opportunities.
This will raise the national and per capita income of the people, thereby increasing their
standard of living.
The economy reaches the second stage of high birth rate and low death rate.
The advancement in science and technology will result in the availability of better medical
facilities.
The eradication of many epidemics and dangerous diseases and better sanitary conditions
reduce the incidence of disease and death.
The birth rate still remains high due to the resistance to change and the long established
customs and beliefs.
Thus there is an imbalance between high birth rate and low death rate resulting in high
population growth, and the country witnesses population explosion.
Stage III: Low Birth Rate and Death Rate
Economic development leads to change in the structure of the economy from an agrarian to
a partially industrialised one.
With the increase in industrialisation, people migrate from rural to urban areas, and there is
a change in the attitude of the people.
With the spread of education, people prefer small families in order to increase the standard
of living.
Thus the birth rate is reduced.
Implementation of better medical facilities, control of disease, and public sanitation result
in a low death rate.
During this third stage of low birth and death rates, the growth of population tends to be
stable.
Almost all countries have passed through these three stages (demographic transition) of
population growth.
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