The following are definitions of some basic terms used frequently within population geography.
Natural Increase - The rate, at which a population increases, basically birth rate minus the death rate, and excluding immigration. This number is usually expressed per 1000 of the population, and may be expressed as a percentage.
Birth Rate- The number of births annually within a country or realm. Usually expressed by numbers of births per one thousand of the population, and may be expressed as a percentage.
Death Rates - The number of deaths annually within a country or region. Usually expressed by numbers of death per one thousand of the population, and may be expressed as a percentage.
Infant Mortality Rates - The number of deaths within a country or region, age 1 or below. Usually expressed by numbers of deaths per one thousand of the population, and may be expressed as a percentage. If infant mortality rates are considered in life expectancy rates and are high, it may impact the numbers significantly.
Life Expectancy Rates - The number of years a newborn can expect to live, calculated annually. Usually expressed as a percentage.
Population Density - The number of people per square mile or kilometer, usually takes total population of a country or region and total area. Can vary dramatically within a state, an example is density figures for Tokyo and all of Japan.
Double Time - The number of years it would take for a population to double in size if it continues to grow at the current rate.
Migration - permanent movement of the population. May be voluntary or forced.
Immigration- migration of the population from one sovereign state to another.
Out- Migration - movement of a population out of a sovereign state, usually a result of a lagging economy or civil strife.
Median Age - the middle or fiftieth percentile in regards to age within a population.
Average Age - the
sum of all ages divided by the total number of the population.
Demographic Transition Models
Demographic transition models
are models that attempt to link economic development to changes in birth
and death rates within a region or country. These models presented below
should reveal a stateís ability to meet the needs of their home population,
and where priorities lie in relation to governmental and economic policies.
The last section presents factors that can disrupt or interrupt the application
of the following stages.
Stage 1 - High Birth Rates - High Death Rates
Often found in underdeveloped
realms. Factors/Conditions found in these areas are as follows: high disease
rates, high infant mortality rates, low life expectancies, undeveloped
medical technology or little access to medical facilities, malnutrition,
and endemic diseases. Population growth overall stays static due to high
death rates, and the populationís age is usually quite young, maybe as
much as 60% of the population may be under 16 years of age.
Challenges for stage one
category: feeding the general population, providing basic medical care,
and educating a young population. Recently controlling H.I.V infection
rates as proved to be a sometimes-overwhelming task within these realms.
Stage Two - High Birth Rates - Low Death Rates
Found in undeveloped realms
and newly industrialized countries. Underdeveloped regions usually have
via governmental policy improved medical technology to provide basic health
care to the general population. Stage two regions have improved basic health
care to the point of combating most endemic diseases and other disease
that is commonly classified as having a cure, treatment, or immunization.
Medical technology here usually does not extend to birth control, treatment
of many cancers, and treatment that requires very high levels of technology
or capital, such as heart disease and H.I.V. Infant mortality rates can
vary dramatically in this category. Some discussion should focus on countries
or realms that remain in this category not due to lack of medical technology
or economic development, but rather due to religious beliefs. Often the
acceptance of a religious doctrine that discourages the use of birth control
will, if accepted by the majority, result in the region consistently remaining
within category 2 despite levels of economic development. Good examples
of this are the influence of Catholicism in Latin America, and Islam within
Middle Eastern countries that have developed rapidly due to oil resources.
This category is worldwide the greatest area of growth, generally this
stage has a relatively young population, overall age is usually determined
by the number of years it has been since transition from stage 1 to stage
Challenges for stage 2 category:
feeding a rapidly growing population, depending on the area of land available,
there may be competition for land devoted to human occupancy and land devoted
to agricultural production, meeting the educational needs of a growing
population, basic medical needs for larger numbers, providing jobs for
large numbers entering the workforce and often providing infrastructure
in cities for a rapidly urbanizing population. In recent years combating
A.I.D.s and H.I.V. has been a difficulty within these regions. An area
that is barely meeting the medical and educational needs of their population
is forced to divert capital towards A.I.D.s education, prevention, and
Stage Three- Low Birth Rates - Low Death Rates
Found in some areas that
are newly industrialized, more often found in the post-industrialized world.
Medical technology and economic development is such that life expectancies
are quite high. Countries or regions that fall within this category usually
have widespread use of some form of birth control. Often immigration is
the primary factor behind overall population growth. Some countries have
static or negative natural growth rates. Generally within this category
you see the median age in the late thirties or early forties and growing
Challenges for category 3:
providing medical care for an aging population, meeting taxation and labor
needs with a shrinking base, treatment and care of a growing elderly population,
immigration policies and/or legislation aimed at increasing the natural
The following are factors
that can interrupt or negate transition; war, fatal diseases without a
known cure, religious doctrine, and famine. You may have this under the
well-known heading of the "four horsemen". All of the following are capable
of rendering all categories to High Birth - High Death, or Low Birth -
Web Links and Exercises
The CIA Factbook gives a country profile on every state in the world. The following exercise demonstrates differences between a state in category 1 of the demographic transition model and a state in category 3.
Go to CIA Factbook - Country Profiles.
This takes to the country
profile section of the CIA Factbook. When you enter this section click
on the countries of The Democratic Republic of Congo and Japan. Compare
the age structure, birth and death rates, infant mortality rates, and life
expectancies and document the differences.
Go to United Nations Population Information Network.
This takes you into the United
Nations page on world population. When this site is contacted, click on
Brief Packet World Population Estimates for 1998. Next, click on Aging,
(at the bottom of the page). What region has the oldest population? Then
go back to World Population Estimates and click on Demographic Impact of
HIV/AIDS. What country is hardest hit by AIDS? How dramatic is the impact?
Go to National Geographic.
This link will allow you
to glimpse what life is like in Tanzanian Refugee Camp. After you reach
link, click on "refugees".