Arithmetic Density
A statistic of population density calculated by dividing a
country’s population by its total land area. In other words,
it is the number of people per square kilometer or square
mile.
Physiological Density
A statistic of population density calculated by dividing a
country’s population by its area of arable land. In other
words, it is the number of people per square mile or
kilometer of farmable land.
Dependency Ratio
The dependency ratio is a measure of the number of dependents aged zero to 14 and over the age of 65, compared with the total population aged 15 to 64. This indicator shows how many people are not working compared to those who are.
Over Population
the condition of being populated with excessively large numbers.
Push / Pull Factors
A model of migration that argues that people are pushed
from their homes by certain negative factors and pulled to
other locations by positive qualities.
Distance Decay
The idea that, all else being equal, as the distance be-
tween two places increases, the volume of interaction between these places decrease. See also Zipf’s Law.
TFR
Total Fertility Rate - The number of children a woman can expect to have in her lifetime, given current fertility rates.
CBR
Crude Birth Rate - A simple measure of fertility that represents the number of children born per 1,000 people in a population in a given year.
CDR
Crude Death Rate - A measure of mortality that represents the number of
deaths per 1,000 people in a population in a given year.
IMR
Infant Mortality Rate - The number of babies who die before age one per 1,000
births.
NIR
Natural Increase Rate - The difference in births and deaths in a population, usually
expressed as a percentage; does not take into account
migration into or out of an area.
Malthusian Theory
Population grows exponentially while food output only grows arithmetically. This would result in a food shortage and famine due to overpopulation.
Neo-Malthusians
Modern population theorists that carry on Malthus’s idea that population growth will lead to global chaos.
Life Expectancy
The average life spans of persons in particular population.
Ravenstein’s Laws
A set of theories about migration developed in the late
nineteenth century by Ernst Georg Ravenstein.
realized that people are more likely to migrate short distances, migrate in steps, and that young people are more likely to migrate
Refugee
A person living outside of his or her own country who can-
not return home because of fear of injury or persecution.
Carrying Capacity
the number of people an area can support before damaging the environment
Population Pyramid
A graphic that shows the number or percentage of men
and women in a population per year group or range of
years; sometimes called a population profile
DTM
A model of demographic change based on Europe’s population in the eighteenth through twentieth centuries . it argues that, as a country modernizes, its fertility and mortality rates drop, but not at the same time. Because death rates drop before birth rates, population increase
will occur.
DTM Stage 1
High Birth, High Death (Low Growth)
DTM Stage 2
High Birth, Rapidly Falling Death (High Growth)
DTM Stage 3
Falling Birth, Slowly Falling Death (Moderate Growth)
DTM Stage 4
Low Birth, Low Death (Stationary Stage)
DTM Stage 5
Zero Population Growth
