1.2.1 Demographic Transition and Population Change Notes

Population Growth Facts

1. For most of human history population growth was negligible due to high mortality (especially among children) despite high fertility rates.
2. Rapid population growth dates back to the late 18th and 19th Centuries due to introduction of basic healthcare and improved living conditions in future HICs.

1. The world population has reached 8 billion and is expected to stabilize by the end of 21st Century at between 10 to 12 billion. By 2100-2150 it could be down to 9 billion.
2. In 2023 India has overtaken China as the most populated country in the world
3. About 10% of world’s population is over 65 - by 2100 this proportion will have risen to one-third
4. The average total fertility rate dropped significantly from 5.06 in 1964 to 3.28 in 1990 and then further to 2.3 currently.

1. Now Over 50% of the world's population can be found in Asia, but its share in global population will decline whereas Africa's will increase.
2. Population growth in Asia will be over by the mid-21st Century, whereas Africa is the only region projected to experience further population growth throughout the 21st Century.

Trends in Fertility, Mortality, and Dependency

Natural Increase: The Balance Between Births and Deaths

Calculating Natural Increase

1. Crude Birth Rate (CBR): Number of live births per 1,000 people per year.
2. Crude Death Rate (CDR): Number of deaths per 1,000 people per year.

$$\text{Natural Increase (%) = CBR - CDR}$$

Fertility Rate: The Drivers of Population Growth

Influencing Factors

1. Status of Women: Higher education and employment opportunities often lead to lower fertility rates.
2. Economic Conditions: In LICs, children may be seen as economic assets, increasing fertility rates.
3. Cultural and Religious Norms: Some societies encourage larger families.
4. Access to Healthcare: Availability of contraception and maternal health services can reduce fertility rates.

Dependency Ratio: Balancing the Working and Non-Working Populations

Calculating Dependency Ratio

$$\text{Dependency Ratio} = \frac{\text{Number of Dependents}}{\text{Working-Age Population}} \times 100%$$

Key Demographic Metrics

1. Life expectancy varies widely across the world.
   1. In HICs, it exceeds 80 years.
   2. In LDCs, it ranges between 50 and 55 years.

Women Generally Live Longer Than Men

1. Factors include lower retirement ages, reduced physical labor, and lower participation in physically dangerous jobs (e.g. mining, construction).
2. Less direct involvement in conflict and significantly lower participation in organized crime and interpersonal violence.
3. Men are also more likely to engage in “self-destructive” and risky behaviors like excessive smoking and drinking.

Population Growth Can Continue Despite Falling Fertility Rates

1. This occurs when a large proportion of the population is in their childbearing years, leading to higher absolute numbers of births even with lower fertility rates.

The Demographic Transition Model Describes Population Change In Stages

1. Imagine two countries: Japan and Nigeria.
   1. Japan faces an aging population with a shrinking workforce.
   2. Nigeria grapples with rapid population growth and a youthful demographic.
2. These contrasting scenarios reflect the stages of the Demographic Transition Model (DTM) and illustrate how trends in fertility, mortality, and dependency shape societies over time.

DTM Shows The Transition From High Birth and Death Rates to Low Birth and Death Rates

The Demographic Transition Model (DTM): Key Concepts

1. The DTM shows how populations change as countries develop, transitioning from high birth and death rates to low birth and death rates over time.
2. It highlights the relationship between economic development and demographic changes.
3. The model is based on historical data from countries like England, Wales, and Sweden, but not all countries follow this exact pattern.
4. Modern developing countries may progress differently, influenced by technological advancements and social policies.

There are 5 Stages to the DTM

Stage 1: High Stationary (Pre-Industrial)

1. High and fluctuating birth and death rates
2. Little to no population growth
3. Characteristic of pre-industrial societies
4. Common causes of death include: poor sanitation and hygiene, limited medical knowledge, food scarcity, high infant mortality, prevalence of diseases.

Stage 2: Early Expanding

1. Death rates begin to fall rapidly
2. Birth rates remain high
3. Period of rapid population growth
4. Falling death rates are caused by improvements in: food supply, basic healthcare, and sanitation.

Stage 3: Late Expanding

1. Death rates continue to remain low
2. Birth rates begin to fall
3. Population is still growing but at a decreasing rate
4. Social changes include: urbanization, access to education, family planning, women entering the workforce.

Stage 4: Low Stationary

1. Both birth and death rates are low
2. Population growth stabilizes
3. Characteristic of developed nations
4. Features include: advanced healthcare, family planning, high cost of raising children, aging population.

Stage 5: Declining (Post-Industrial)

1. Birth rates fall below death rates
2. Aging population leads to an overall population decline
3. Characterized by: aging population, fertility below replacement rate, high dependency ratio, economic challenges.

Not All Countries Follow the Exact Scheme of the DTM

1. Though widespread, the DTM is based primarily on European experiences, where alternative demographic transitions may also exist.
2. The time frame varies significantly between countries.
3. Modern developing countries may progress through stages differently than historical examples.

Population Pyramids Graphically Represent Age and Sex Distribution

Key Components of Population Pyramids

1. Vertical axis: Age groups (typically in 5-year bands)
2. Horizontal axis: Population percentage or absolute numbers
3. Left side: Male population
4. Right side: Female population

There are Three Main Types of Pyramids

Expanding (Stages 1-2 of DTM)

1. Wide base, narrow top represents high birth rates, high death rates (if slopes are concave), and large young dependent populations.
2. They are characterized by a high fertility rates, short life expectancy, and rapid population growth.

Stationary (Stages 3-4 of DTM)

1. More rectangular shape represents similar percentages across age groups and a relatively stable population.
2. They are characterized by moderate birth and death rates, a longer life expectancy, and slower population growth.

Contracting (Stage 5 of DTM)

1. A narrow base, with a wide middle, relatively wide top represents low birth rates, low death rates, and an aging population.
2. They are characterized by having below replacement fertility levels, a very long life expectancy, and population decline.

Reflection and Broader Implications