Human Population and Demographic Transition Study Guide

The theory of demographic transition studies demographics and social characteristics using census data, surveys, and statistical models to analyze the size, movement, structure, and movement of human populations over space and time.

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The demographic transition theory of population growth was coined by the American demographer Frank W. Notestein (1945). It uses methods from history, economics, anthropology, sociology, and other fields to influence economic growth, structural productivity growth, living standards, savings rates, consumption, and investment of a country.

What is demographic transition?

The theory of demographic transition refers to the historical shift from high birth rates and death rates in societies with minimum technology, literacy rates, and economic development to low birth rates and low death rates in societies with advanced technology, higher education, technological development, and better economic conditions.

The classical demographic transition model can be divided into four stages.

  • Pre-Transition Stage: Characterized by high birth rates and high fluctuating death rates.
  • Early Transition Stage: The death rate begins to fall during the early stages of transition. The population starts growing rapidly as the birth rate remains high.
  • Late Transition Stage: The birth rate starts to decline, and the rate of population growth decelerates.
  • Post –Transition Stage: Low birth and death rates in society lead to negligible population growth or even decline.

These four stages of demographic changes are depicted on the graph given below:

Demographic transition graph Source

What is Population Growth?

Population growth explains the increase in the number of people in a population caused exclusively by fertility, mortality, and migration. Population change can be either positive or negative, depending on the balance of births and deaths. In case of more deaths, the world's population will grow slowly or can even decline. The growing population is measured in both absolute and relative terms.

What is the population of the world?

As per the 2018 World Population Data Sheet, there were an estimated 7.5 billion people on the planet, and the population continues to grow. The current live population of the world is 7.9 billion as of December 2021. However, the world population is projected to increase from 7.8 billion in 2020 to 9.9 billion by 2050.

What is the American population?

Based on the World meter elaboration of the latest United Nations, the current population of the United States of America is 333,770,690 as of December 5, 2021.

What is the population growth in India?

Presently, India is the second most populated country globally and represents almost 17.85%, or nearly a fifth of the overall global population. With the population growth rate at 1.2%, an overall increase of 1.53 billion people is predicted by the end of 2030 due to the persistence of high fertility and declining mortality rate.

Define Demographic Cycle

Stages of the demographic cycle Source

The demographic cycle or population cycle refers to the evolution of the population profile of a country, region, or other defined geographical area. The four stages of population change identified in the demographic cycle are:

  • A stationary phase is marked by high birth, death rates and a relatively low population.
  • Uneven population density due to increased urbanization and industrialization.
  • Low birth and death rates result in relatively steady population growth.
  • Stagnation or decline in the total population due to the number of deaths surpassing the births.


Demographic transition is considered as the most acceptable theory of population growth because:

  • It is based on the actual population growth trends of the developed countries of Europe, which is equally applicable to other developing countries of the world.
  • Numerous economic-demographic models have been developed on this evolutionary process so that underdeveloped countries can attain development and become self-sustained.


1. What happens to the human population during a demographic transition?

Throughout this demographic transition, the declining birth rates followed by the declining death rates usher in an era of rapid population growth. This transition usually brings development and transformation from an agrarian into an industrial society.

2. What is a demographic transition theory, and how does it affect the world population?

  • The demographic transition theory studies the relationship between economic development and population growth.
  • It discusses changes in the rate of birth/death and the growth of the population accompanied by economic development.
  • It is also used to predict the population of any particular area.
  • Declining mortality preceding a lower fertility rate leads to an increase in population.
  • In the Malthusian world, these positive demographic changes put increased pressure on agriculture, leading to starvation and a higher death rate which again causes the population to balance itself.

3. What is the significance of the demographic transition in human population studies?

The demographic transition model has enabled economies to convert more of the gains from factor accumulation and technological progress into increased income per capita. Firstly, the decline in population growth reduced the growing capital and infrastructure dilution, increasing the number of resources per capita.

Second, lower fertility rates led to fewer but healthier children, enhancing the human capital and higher labor productivity. Third, a younger population temporarily increases the labor force and mechanically boosts productivity per capita.

4. Is the human population increasing or decreasing?

The world population has increased from 1 billion in 1800 to 7.7 billion today. This implies that, on average, the population grew very slowly from 10,000 BCE to 1700, with an annual increase of 0.04%.

5. What happens during the transitional stage of the demographic transition?

  • During the demographic transition stages, a country develops from a non-industrial to an industrial economy to create conditions for higher longevity. Improved health care facilities coupled with investments in sanitation and infrastructure bring a sharp drop in the death rates.
  • However, birth rates remain unchanged, leading to an increase in the population.
  • Death rates fall during the mature industrial stage as economic developments bring birth rates down slightly.
  • The total population continues to climb up in an exponential j-curve. However, in the post-industrial stage, the population growth begins to level off as the birth and death rates tend to follow each other.

6. Why does the population change?

Changes in birth and death rates are the major reasons for population changes, whether in an individual country or worldwide.

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  5. Demographic Transition Theory – Human Geography UPSC. https://lotusarise.com/demographic-transition-theory-upsc/. Accessed 6 Dec, 2021.