Population Growth

Population growth refers to the increase in the number of individuals living in a particular area over a specified period of time. It is a fundamental demographic concept that has significant implications for societies, economies, and the environment.

Population growth occurs due to two primary factors: natural increase (births minus deaths) and net migration (immigration minus emigration). When the number of births exceeds the number of deaths and more people immigrate to an area than emigrate from it, the population grows. Conversely, when deaths outnumber births or more people leave an area than enter it, the population declines.

Basic Concepts of Population Geography

Growth of Population

The growth of population refers to the change in the total number of individuals living in a particular area over a specific period of time. It can be measured in absolute numbers or as a percentage increase or decrease relative to the population size at the beginning of the time period. For example, if we deduct the population of India 2001 (102.70 crore) from population of 2011 (121.02 crore) then we shall get the growth of population (18.15 crores) in actual numbers.

Population growth can occur through two primary mechanisms:

1.     Natural Increase: Natural increase refers to the difference between the number of births and the number of deaths in a population over a given period. When births outnumber deaths, the population experiences natural growth. Factors such as fertility rates, mortality rates, and life expectancy influence natural increase.

2.     Net Migration: Net migration refers to the difference between the number of people immigrating to an area (in-migration) and the number of people emigrating from that area (out-migration) over a given period. Positive net migration, where more people are moving into the area than leaving it, contributes to population growth. Factors such as economic opportunities, political stability, social networks, and environmental conditions influence migration patterns.


 Components of Population Change

Three main components are

  1. Births (Natality): The number of live births occurring within a population during a specified period..
  2. Deaths (Mortality): The number of deaths occurring within a population during a specified period.
  3. Migration: Migration refers to the movement of people into or out of a particular area. It is typically divided into two components:
    • Immigration: The inflow of individuals into a population or area from another location or country.
    • Emigration: The outflow of individuals from a population or area to another location or country. Net migration is the difference between immigration and emigration


Crude birth rate (CBR)

The Crude Birth Rate (CBR) is a demographic measure that represents the number of live births occurring in a given population per 1,000 people per year. It is a fundamental indicator used by demographers and policymakers to understand fertility patterns within a population.

The formula to calculate the Crude Birth Rate is as follows:

Crude Birth Rate (CBR)=  Bi/P X1000 where Bi is live birth per year, P is mid year population


Key points about the Crude Birth Rate:

1.     Expressed per 1,000 Population:.

2.     Not Adjusted for Age or Sex: The term "crude" indicates that the rate is not adjusted for the age or sex composition of the population

3.     Use in Demographic Analysis: The CBR is used in demographic analysis to assess fertility levels, trends, and variations among different populations.

4.     Influenced by Social and Economic Factors: The CBR is influenced by various social, cultural, economic, and environmental factors, including access to healthcare, education, family planning services, cultural norms, socioeconomic status, and government policies related to family planning and maternal health.

5.     Interpreting Changes in CBR: Changes in the Crude Birth Rate over time can indicate shifts in fertility patterns within a population. A declining CBR may suggest decreasing fertility rates, while an increasing CBR may indicate rising fertility levels or changes in population structure.

Overall, the Crude Birth Rate provides valuable insights into fertility trends and patterns within a population, serving as a vital indicator for demographic analysis, policy development, and planning related to healthcare, education, and social services.


Crude Death Rate (CDR)

The Crude Death Rate (CDR) is a demographic measure that represents the number of deaths occurring in a given population per 1,000 people per year.


Interpreting Changes in CDR: Changes in the Crude Death Rate over time can indicate shifts in mortality patterns within a population. A declining CDR may suggest improvements in healthcare, disease prevention, and overall health outcomes, while an increasing CDR may indicate worsening health conditions or changes in population structure.



Migration refers to the movement of people from one place (Place of origin) to another place (Place of destination), either within a country or across international borders.


Emigration and Immigration:

Immigration: Migrants who move into a new place are called Immigrants.

Emigration: Migrants who move out of a place are called Emigrants

So emigrant from our country is immigrant in another country


Migration can also be
Temporary and Permanent Migration: Migration can be temporary, such as seasonal labor migration or temporary work visas, where individuals move to another location for a specific period before returning to their place of origin. Conversely, permanent migration involves


Reasons why people migrate


People migrate for various reasons, which can be broadly categorized into push and pull factors. These factors influence individuals' decisions to leave their place of origin and settle in a new location. Here are some common reasons why people migrate:

1.     Economic Opportunities: Economic factors play a significant role in migration decisions. Individuals may migrate in search of better job opportunities, higher wages, improved living standards, and economic stability. Economic disparities between regions or countries can motivate people to seek employment and financial security elsewhere.

2.     Education and Training: Migration for educational purposes is common, particularly among students seeking higher education opportunities or specialized training programs not available in their home country. Individuals may migrate to access quality education, pursue academic or professional goals, or gain specialized skills and knowledge.

3.     Family Reunification: Family reunification is a significant driver of migration, particularly in countries with established immigrant communities. People may migrate to join family members who have already settled in another country, reunite with spouses, parents, children, or siblings, or maintain family ties and support networks.

4.     Escape from Conflict and Violence: Conflict, political instability, persecution, and human rights abuses can force people to flee their homes and seek safety and protection in other countries. Refugees and asylum seekers migrate to escape war, violence, persecution based on race, religion, nationality, political opinion, or membership in a particular social group.

5.     Environmental Factors: Environmental factors such as natural disasters, climate change, environmental degradation, and resource scarcity can displace populations and trigger migration. People may migrate from areas affected by floods, droughts, hurricanes, or sea-level rise, or regions experiencing land degradation, deforestation, desertification, or pollution.

6.     Better Quality of Life: Migration may be driven by the desire for a better quality of life, including access to healthcare, housing, sanitation, clean water, and social services. Individuals may migrate to countries with higher standards of living, better infrastructure, healthcare systems, and social welfare programs.

7.     Political Freedom and Human Rights: Some individuals migrate to countries that offer political freedom, democracy, respect for human rights, and rule of law. They may seek refuge in countries with democratic institutions, freedom of expression, and protection against discrimination, censorship, or political persecution.

8.     Cultural and Social Reasons: Migration can be motivated by cultural or social factors, including the desire to experience different cultures, languages, lifestyles, and social environments. People may migrate for personal fulfillment, adventure, or to pursue relationships, friendships, or community ties.

Overall, migration is a complex phenomenon influenced by a combination of push and pull factors, including economic, social, political, environmental, and personal considerations. Understanding the diverse reasons why people migrate is essential for policymakers, governments, and international organizations to develop effective migration policies, address migration challenges, and support the needs and rights of migrants and host communities.