Topic 1 (1)
Topic 1: Introduction to Social Demography
Definition of Demography
The study of size, composition, and distribution of human populations and how these factors change over time.
Key elements: fertility, mortality, migration.
Demographic History
Historical records indicate population enumerations in Babylon (before 3800 B.C.), China (about 3000 B.C.), and Egypt (circa 2500 B.C.).
Ancient Greece and Rome conducted population counts for governance and taxation purposes.
Global Population Distribution (2000)
Regional Populations
Europe: 25% (1900) to 14% (2000)
Asia: 60% (2000)
Africa: 4.5% (2000) to 10% (projected)
Latin America and Caribbean: 8% (2000)
North America: 5% (2000)
Definitions Related to Demography
Demography
Derived from Greek: (dēmos) "people" and (graphia) "write or record."
Fundamental to understanding human populations and their ecological context.
Demographic Characteristics
Traits describing a population: gender, age, ethnicity, language, disabilities, etc.
Collected via demographic statistics through censuses or special investigations.
Social Demography
Uses demographic data to describe and predict social phenomena.
Differentiates from formal demography, emphasizing social-status impacts on population.
Development of Social Demography
Emergence as Academic Discipline
Originated in the U.S. during the latter half of the 20th century.
Term "social demography" coined by Kingsley Davis in 1963.
Key publications: "Social Demography" (1970) by Thomas Ford and Gordon DeJong; first social demography conference in 1975.
Historical Context of Demographic Studies
Census Data
Early census documented population and social characteristics for governance.
Examples: Babylonians, Chinese, Egyptians; ancient Greeks and Romans.
Registration Data
Systematic recording of vital events began in the Middle Ages; focused on nobility initially.
Henry VIII mandated parish records in 1538.
Basic Concepts in Demography
Fertility Concept
Crude Birth Rate (CBR): Total births divided by midyear population, expressed per thousand. Formula:
b = 1000 * (B/P).Age-Specific Fertility Rate (ASFR): Total births to women age i during the year divided by total women age i. Expressed per thousand:
asfr_i = 1000 * (B_i/W_i).Total Fertility Rate (TFR): Sum of age-specific fertility rates multiplied by year intervals, divided by 1000.
Mortality Concept
Crude Death Rate (CDR): Total deaths divided by midyear population, expressed per thousand. Formula:
d = 1000 * (D/P).Life Expectancy at Birth (e0): Average years a newborn can expect to live.
Migration Concept
Migrants: Individuals changing residence (in-migrants and out-migrants).
Net Migration: Difference between in-migrants and out-migrants.
Age and Sex Composition
Age Pyramid
Visual representation illustrating age and sex distribution in a population.
Provides insights into historical trends of fertility, mortality, and migration.
Population Growth and Transition
Population Growth Concept
Change in population = births - deaths + net migration:
delta P = B - D + I - O.Doubling time approximated by
T2 = 72/r, where r is the annual growth rate.
Demographic Transition Model
Represents transition from high birth and death rates to low rates.
Stages: High, Early Expansion, Late Expansion, Low Stationary.