Factors Affecting Population Growth
1. Key Definitions
● Population: Total inhabitants of a specific country.
● Population Growth Rate: Change in population size, expressed as a percentage.
2. Factors Influencing Population Growth
● Birth Rate: Higher rates increase population.
● Death Rate: Lower rates increase population.
● Net Migration: More immigration than emigration increases growth rate.
3. Variation by Country
● LEDCs: Highest growth rates (e.g., Niger, Mali, Zambia).
● MEDCs: Lowest growth rates, with some like Italy and Japan experiencing population
decline.
4. Immigration vs. Emigration
● Immigration: Inward movement to a country.
● Emigration: Outward movement from a country.
Reasons for Different Rates of Population Growth
1. Causes of Population Change
● Migration: Involves movement of people.
● Natural Population Change: Difference between birth and death rates.
2. Natural Population Change Factors
● Death Rate Decrease: Improved agriculture, medicine, technology, housing, and
sanitation.
● High Birth Rate in LEDCs: Limited family planning, cultural practices, large families for
support.
● Falling Birth Rates in MEDCs: Access to contraception, changing social norms, high
child-rearing costs.
Overpopulation and Underpopulation
1. Overpopulation
● Impacts: Pollution, crime, unemployment, food & water shortages, pressure on services.
2. Underpopulation
● Impacts: Higher taxes, wasted resources, worker shortages, reduced exports, fewer
consumers.
3. Optimum Population
● Definition: Balance between population and resources for the highest standard of living.
Population Distribution and Structure
1. Population Structure
● Characteristics: Age, sex, ethnicity, religion.
● Population Pyramids: Visual representation of age and sex distribution.
2. Examples
● Niger (LEDC): High birth rate, low life expectancy, young dependent population.
● USA (MEDC): Decreasing birth rate, increasing life expectancy, larger working-age
population.
● Japan (MEDC): Low birth rate, high life expectancy, ageing population.
Effects of Population Changes
1. Ageing Populations
● Impacts: Increased pension payments, care homes demand, higher healthcare costs,
smaller labor force, higher wages.
2. Falling Birth Rates
● Impacts: School closures, future labor shortages, government incentives for larger
families, migration law adjustments.
3. Migration Effects
● Impacts: Population structure imbalance, pressure on services, housing shortages,
traffic congestion, pollution, food shortages.
