जनसङ्ख्या अध्ययन र सिद्धान्तहरू

Introduction

The Optimum Theory of Population was developed mainly by the English economist Edwin Cannan and later supported by Hugh Dalton, Lionel Robbins and others. Instead of saying that population is always too large or too small, it says that every country has an optimum (ideal) population.

Main idea

At a given level of resources, technology and capital, there is one population size at which per capita income and the standard of living are the highest. This is the optimum population.

• Under-population: If the population is less than the optimum, resources are not fully used and per capita output is below its maximum. Increasing population raises output per head.
• Optimum population: Output per head is at its maximum, and resources and labour are in the best balance.
• Over-population: If the population is more than the optimum, the extra people reduce output per head (the law of diminishing returns) and cause unemployment, poverty and pressure on resources.

Illustration: Starting with a small population, per capita income rises as people increase until it reaches a peak at the optimum point. After the peak, per capita income falls as population keeps growing.

Dalton's formula for the measure of the optimum is

$M = \frac{A - O}{O}$

where $A$ is the actual population and $O$ is the optimum population. If $M$ is positive, there is over-population; if negative, under-population; and if zero, the population is optimum.

Features

• The optimum is not fixed. It changes as technology, capital, skills and resources change.
• The aim is the highest standard of living, not the largest population.

Merits: It is more realistic than Malthus's theory, considers both growth and resources, and gives a practical goal for population policy.

Criticisms: It is very difficult to measure the optimum in practice; it depends on many changing factors; and it ignores migration and trade between countries.

Conclusion: The theory shows that the quality of life depends on the balance between population and resources. Nepal, with limited land and many unemployed, should aim to bring population in line with its optimum.

Sociology and Economics.

Population studies is interdisciplinary — it draws on Sociology (social structure, family, migration) and Economics (resources, employment, development), among others like Geography, Demography and Statistics.

Introduction to Population Studies

Population studies (also called demography, from the Greek demos = people and graphos = description) is the systematic, scientific study of human population. It deals with the size, structure (composition), distribution and growth of population, and with the changes in these features over time through the three basic demographic processes — birth, death and migration. It examines not only how many people there are, but also who they are (age, sex, caste, ethnicity, education, occupation) and where and how they live. Because population is both a cause and a consequence of social and economic conditions, population studies draws on sociology, economics, statistics, geography, biology and public health, and is closely linked with development planning. In Nepal, population studies is important for understanding problems such as rapid growth, high dependency, unemployment, migration and pressure on land and resources.

Three objectives of population studies

1. To describe and measure population change: To collect, analyse and interpret data on population size, growth rate, birth rate, death rate and migration, so that the actual demographic situation of a country or region can be known accurately.

2. To study the composition and distribution of population: To examine the age–sex structure, literacy, occupation, caste, ethnicity, religion and spatial distribution of people, so that the working and dependent groups and regional imbalances can be identified.

3. To help in policy formulation and planning: To provide reliable demographic information and projections that the government and other agencies use for planning in education, health, employment, housing, food and family planning, and for solving population-related problems.

(Other acceptable objectives: to explain the causes and consequences of population growth; to study the relationship between population and development; to create public awareness about population issues; to forecast future population trends.)

Population studies is the systematic study of the size, structure, distribution and change of human population. Its five main importance are:

1. Formulation of population policy: It provides reliable data on birth rate, death rate and migration, which the government uses to frame suitable population policies and programmes.

2. Planning for economic development: Figures on the size and growth of population help planners decide how much to invest in food, employment, industries and infrastructure.

3. Proper utilisation of resources: It shows the relation between population and available natural and human resources, helping to balance the two and avoid over-exploitation or under-use.

4. Planning for social services: Data on age, sex and distribution of population help in estimating the need for schools, hospitals, housing, drinking water and other social services.

5. Solution to population problems: By revealing the causes and consequences of problems like rapid growth, unemployment, poverty and migration, it helps in finding appropriate remedies.

Besides these, population studies also help in manpower planning, environmental protection and understanding social change.

Demographic transition theory (Warren Thompson, Frank Notestein) explains how a country's population changes as it develops, through the following stages:

1. Stage 1, high stationary: High birth rate and high death rate, so slow growth.
2. Stage 2, early expanding: Death rate falls (better health) but birth rate stays high, so rapid growth.
3. Stage 3, late expanding: Birth rate also starts to fall, so growth slows.
4. Stage 4, low stationary: Low birth and death rates, so growth is small and stable. (Some versions add a fifth stage with declining population.)

Is it relevant to Nepal? Yes, to a large extent.

• Until about the 1950s Nepal was in Stage 1: high birth and death rates and slow growth.
• After the 1950s, improvements in health services, immunisation and sanitation reduced the death rate quickly, while the birth rate stayed high. Population growth was high (above 2% a year in 1970s to 1990s). This is Stage 2.
• Since the 1990s, the birth rate has fallen because of family planning, education of girls, later marriage and migration. The growth rate dropped to about 1.35% (2011) and further to about 0.92% (2021). Nepal is now in the late expanding stage (Stage 3), moving towards Stage 4. TFR is now about 2.1.

Limitations in the Nepalese context: Migration has a large effect on Nepal's population, which the theory ignores. Also, the decline of the birth rate came from government programmes and not only from industrialisation, as in Europe.

Conclusion: The overall pattern of Nepal's population change fits the theory, so it is relevant, although migration and policy make the Nepalese path somewhat different.