Spatial Demography -- Population Patterns, Basic Principles
I. Definitions:
- Demography: The study of population
- Population Geography: Spatial aspects
of demography or population, answers questions of where? And why there?
- Spatial Epidemiology and Medical Geography:
studies the origin and diffusion of disease.
- At-Risk Principle
II. Demographic Accounting Equation
- P(t+1)=P(t)
+B(t, t+1)-D(t, t-1) natural change
+I(t, t+1)-E(t, t-1) net migration
- Internal Migration vs. International Migration
Internal: Between states within a country
International: Between countries
- Composition of Migration: Who is migrating where?
--example: California, most immigrants come to L.A.
III. Constructing and Interpreting Rates
- Demographic Rates and Measures
- Rate: the frequency of occurrence of a demographic
event for a population at risk over a given time period.
- Crude Birth Rate (CBR): annual number of live births
per 1,000 population
- Crude Death Rate (CDR): annual number of deaths
per 1,000 population
- Total Fertility Rate (TFR): average number of children
born to each woman if during her childbearing years she bore
children at current years rate fro women her age.
- Expectancy of Life at Birth (or age X)(e0): the
amount of years you are expected to live (differs between countries).
- Doubling Time: Amount of time it takes for a country
to completely double its population (ln(2)/r)
- Examples:
CBR > CDR natural population
increase
CBR < CDR natural population
decrease
Example: Syria
(CBR=33, CDR=6)
Natural increase: 33-6=27 per 1,000 or 2.7%
Doubling Time: ln(2)/.027=25.7 years
Example: Afghanistan
(CBR=42, CDR=17)
Natural Increase: 42-17=25 per 1,000 or 2.5%
Doubling Time: ln(2)/.025=27.7 years
Example: Japan
(CBR=10, CDR=8)
Natural Increase: 10-8=2 per 1,000 or .2%
Doubling Time: ln(2)/.002=347 years