Fertility Factors, Population Trends, and Demographic Shifts
Factors Influencing Fertility
Factors influencing fertility include:
- Cost of raising children, impacting income needed to find a partner, especially for women due to offspring investment.
- Contribution of children’s labor to family income.
- Economic contribution of children to parents in old age.
- Cultural aspects influencing the desired number of children.
- Time a community dedicates to children.
- Biological aspects (food, lactation periods) and social aspects (family structure, economics, religion).
Population Policies and Trends
Two trends emerge when implementing population policies to reduce fertility:
- Demographic policies: A package of political, social, and cultural actions taken to intervene in the population.
- One trend involves media offering contraceptives, while the other focuses on social, cultural, and economic development. Without cultural change, demographic policies are likely to fail.
Malthusianism and Neo-Malthusianism
Malthusianism: Malthus argued that food production increases arithmetically while population increases geometrically, leading to food shortages.
Neo-Malthusianism: Population growth outpaces job creation relative to consumption, resulting in low consumption per person. Malthusianism relates to food scarcity, while Neo-Malthusianism connects population to development.
Population Development Phases
- Stationary Phase: High birth rate and high mortality rate.
- First Phase of Expansion: High birth rate and decreasing mortality rate.
- Late Expansion Phase: Decreasing birth rate and stabilized mortality rate.
- Stationary Phase (Low): Low fertility and mortality rates, resulting in little to no population growth.
Key Demographic Indicators
- Dependent Population: The portion of the population that is not working.
- Dependency Ratio: The ratio between the adult population and the dependent population.
- Aging Rate: The percentage of people over 65 years old in the total population.
- Aging Index: The ratio between the number of older people and the number of people aged 0 to 14 years.
- Infant Mortality: The number of newborn deaths in the first year of life.
- Life Expectancy: The average number of years a person is expected to live from birth.
- Synthetic Fertility Index: The average number of children a woman is expected to have in her lifetime if fertility rates remain constant.
Population Growth and Resource Depletion
Population increase leads to:
- Resource depletion.
- Food and water shortages.
- Reduction in cultivated land per person.
- Increased land use for construction.
- Overexploitation of land.
- Increased soil erosion and loss of fertile soil.
- High demand for water and fossil fuels.
- Deforestation.
- Biodiversity loss.
Development and Social Change
Pressure on the environment depends on population size, technological development, and social structure. Mismanagement of the economy, inappropriate environmental management, and unequal social or political structures also contribute.
Demographic Rates and Indicators
- Birthrates: Number of live births per thousand divided by the total population.
- Population Pyramids: Progressive (wide base) or regressive (narrow base).
- Gross Reproduction Rate: The ratio between the number of daughters born to a generation of women and the number of women in that generation.
- Net Reproduction Rate: Accounts for the number of women who die before childbearing.