Global Demography 1

Global Demography Concepts and Population Pyramid

• Presented by Dr. Rufaidah Al Dabbagh and Prof Abdulaziz Binsaeed.

• Date of presentation: September 26, 2018.

Objectives

• Define demography and population dynamics.

• Apply demographic concepts in health systems.

• Describe major sources of population data.

• Explain features of population pyramids and compare developed vs. developing countries.

• Understand the demographic equation.

• Learn about demographic transition theory.

• Assess the effect of population momentum on growth.

• Discuss migration and its effects on population size.

• Define and interpret rates of population increase and doubling time.

What is Demography?

• Scientific study of human populations encompassing three domains:

  • Change in population size.

  • Composition of a population.

  • Distribution of a population in space.

Sources of Population Data

• Census data.

• Ministry of Health statistics.

• World Health Organization statistics.

• United Nations statistics.

• World Bank statistics.

Importance of Demography

• Community health is influenced by the interaction between population size and space.

Determinants of Population Size, Distribution, and Composition

• Factors include:

  • Economic growth.

  • Fertility.

  • Marriage.

  • Mortality.

  • Social migration.

  • Mobility.

Fertility

• Defined as the actual bearing of children, influenced by:

  • Age at marriage (inverse relationship).

  • Duration of married life.

  • Spacing of children.

  • Education level (inverse relationship).

  • Economic status (inverse relationship).

  • Religion.

  • Nutrition (inverse relationship).

  • Family planning.

  • Physiological, biological, cultural, and social factors.

Measures of Fertility

1. Crude Birth Rate (CBR):

   • Number of live births per year per 1000 estimated mid-year population.

2. General Fertility Rate (GFR):

   • Number of live births per 1000 women aged 15-49 in a given year.

   • Challenges include not all women being at risk for childbirth.

3. General Marital Fertility Rate (GMFR):

   • Number of live births per 1000 married women aged 15-49 in a given year.

4. Age-specific Fertility Rate (ASFR):

   • Number of live births in a specific age group per 1000 women in that age group.

5. Total Fertility Rate (TFR):

   • Average number of children a woman would have during her reproductive years based on current birth rates.

   • Sum of age-specific fertility rates.

Global Total Fertility Rate (TFR)

• Projected values for global fertility from 1990 - 2100 show a declining trend.

Impact of Fertility on Population Age Distribution

• High fertility correlates with a high proportion of young people (developing countries).

• Low fertility correlates with a higher proportion of older individuals (developed countries).

Migration Statistics

• According to UN estimates, 258 million people live outside their country of birth, with a significant proportion being refugees.

• Countries hosting the most migrants include:

  1. USA: 49.8 million.

  2. Saudi Arabia: 12 million.

  3. Germany: ~12 million.

  4. Russia: ~12 million.

  5. UK: 9 million.

• Migration often moves from low-income to high-income countries for better opportunities.

Migration's Importance

• Helps predict population trends and shapes economic growth.

• Younger and healthier migrants typically seek work in more industrialized areas.

Relationship Between Fertility, Migration, and Economic Growth

• Low fertility can stimulate economic growth.

• Economic growth can encourage birth control and influence migration patterns.

Mortality

• Mortality Rate: Number of deaths in a population over a specific period, expressed per 100 or 1000 individuals.

• Crude Death Rate (CDR): Number of deaths per 1000 mid-year population.

Measures of Mortality

• Includes age-specific mortality rates, cause-specific mortality rates, infant mortality rates, and maternal mortality rates.

Stages of Demographic Transition

1. Stage 1 - High Stationary: High birth and death rates.

2. Stage 2 - Early Expanding: Birth rates stable, death rates declining (typical in developing countries).

3. Stage 3 - Late Expanding: Death rates decline further, birth rates begin to fall (population growth).

4. Stage 4 - Low Stationary: Low birth and death rates.

5. Stage 5 - Declining: Birth rates lower than death rates (population decline, example: Germany).

Expectation of Population Growth (1950-2100)

• Graph depicting fluctuations in birth and death rates over time.

Limitations of Demographic Transition Model

• Does not take into account migration effects.

Measuring Population Growth

• Formula: Annual growth rate = Crude birth rate - Crude death rate.

Annual Population Growth Rates

• Categorized by growth rates and corresponding years required for population to double in size.

Saudi Arabia's Unique Demographic Position

• Economic development, women’s education, and changing fertility rates.

• Demographic transition lag observed as fertility rates have not declined rapidly.

Population Pyramid

• Visual representation of age distribution in a population, revealing fertility and mortality insights.

• Analysis involves understanding gender ratios and age group proportions.

Types of Population Pyramids

1. Expansive: High birth rates, triangular shape, indicates growth.

2. Stationary: Equal age group numbers, stable population.

3. Constrictive: Narrow base, low birth rates, usually indicates higher living standards and education.

Additional Measures of Population Distribution

• Sex Ratio: The proportion of males to females in the population.

• Dependency Ratio: Measure of dependencies in the population, important for economic planning.

• Population Density: Total population in a region divided by the region's area.

Conclusion

• Understanding demographic trends and population structures is essential for planning and addressing health and economic policies.