Demography (BS2 CH9) Flashcards
Demography
Demography is the quantitative study of human populations.
Demographers are interested in a number of important aspects of human populations:
- Size (raw numbers)
- Structure and composition (ages and ethnic/racial makeup, for example)
- Spatial and geographic distribution (urban/rural, province vs. province, etc.)
Demography also involves the study of how these elements of a society may change over time as the result of many factors including births, deaths, aging, and migration.
Demographers are interested in a number of important aspects of human populations:
- Size (raw numbers)
- Structure and composition (ages and ethnic/racial makeup, for example)
- Spatial and geographic distribution (urban/rural, province vs. province, etc.)
Demographic chang
Demographic transition theory, first put forth by Warren Thompson in 1929, proposes that societies generally move through four stages of development as they transition from pre-industrialized to fully industrialized and developed.
At each stage of development, the key relationship is between the fertility and mortality of the population.
Demographic transition theory : Stage 1
Stage 1: the population has both high fertility and high mortality.
a. Although there are many births, the pre-industrial effects of natural disaster, starvation, and disease are so significant that the mortality rate is high enough so that there is little to no population growth.
Demographic transition theory -Stage 2
Stage 2: the population still has high fertility but mortality is sharply lowered.
a. During this stage, the population rapidly increases.
b. High fertility is sustained because of the combined effects of traditional institutions encouraging procreation as well as increased standards of living.
c. The mortality rate, however, drops significantly because of those same increased standards of living.
Demographic transition theory -Stage 3
Stage 3: the population’s fertility lowers.
During this stage, the rate of population growth decreases.
Fertility begins to diminish because of social changes that undermine traditional institutions favoring procreation.
Family planning becomes common.
Demographic transition theory -Stage 4
Stage 4: the population’s fertility and mortality become equal.
a. In this stage, the population is stable.
Much of the developing world remains in stage 2 and therefore will continue to grapple with problems of overpopulation.
In general, decreases in fertility rate correlate with increased social and economic development.
Dependency ratio
- Overpopulation is problematic for developing nations because it increases the dependency ratio.
- Dependency ratio is the number of non-working individuals in a population per every 100 working individuals.
- Because of the high birth rate in stage 2, the population will be skewed younger, and therefore will have fewer people of working age than it needs.
- Resources are shunted away from economic development and growth and instead must be used to feed and sustain the growing population.
dependency ratio 2
Many European countries have potentially entered a stage after stage 4 in which mortality exceeds fertility.
This contraction of the population will also cause an increase in the dependency ratio.
In this case, the population will have too many elderly individuals who have retired from the workforce.
A large portion of the resources of the nation must be devoted to caring for these members of society while a smaller proportion of the population is economically productive.
Although the U.S. has an aging population and a diminished fertility, the population continues to grow because of immigration.
Malthusian theory 1
Malthusian theory, put forth in the late 18th century by Anglican priest Thomas Malthus, proposed that improvements in resource availability (especially that of food) would lead to population growth, which would then lead back to limitations on resources.
Thus, there would be a limit on the average standards of living that could be attained, because population growth would outstrip resource availability and allocation.
This mismatch of resources and population would thus cause increased population densities and limited food access, leading to disease and famine, especially amongst lower classes with less resource availability.
This situation is termed a Malthusian catastrophe.
Malthusian Theory 2
Malthus stated that “the increase of population is necessarily limited by the means of subsistence,” meaning on the one hand that populations are limited by limited resources, but also on the other hand that populations can expand with increased resources.
Malthus saw population growth as an inevitable consequence of a state of increased abundance of resources (e.g., food) and noted that abundance is typically used to sustain population growth, not to improve overall average standards of living.
This misappropriation of resources is termed the Malthusian trap or the Malthusian spectre.
Malthusian Theory 3
Malthus’ ideas—notably that there are limits on the population levels that the environment’s natural resources can sustain—were influential on the thinking of pioneering evolutionary biologists Charles Darwin and Alfred Russel Wallace.
Malthus classified checks on human population growth into positive checks and preventive checks.
• Positive checks such as war, disease, and famine actively control populations. Malthus later classified positive checks under the term “misery.”
Preventive checks involve reasoned predictions about a future state of being and the ability to support that state with current (or future) resources.
Example: A single person earning a modest, but sufficient, salary with no prospect for earning much more in the future may elect not to have children, even if married in the future.
factors contributing to demographic change
Fertility refers to the actual number of births in a population.
Fecundity refers to potential for childbearing.
Crude birth rate is number of births per 1,000 people.
A better measure of the fertility of a population is the total fertility rate. The total fertility rate is the number of children that an average individual in the population would have over an entire life.
Fertility is linked to the industrialization of a society.
More industrialized countries have lower fertility rates.
factors contributing to demographic change 2
Mortality is the frequency of deaths in a population.
Crude death rate is number of deaths per 1,000 people.
Demographers will also consider age-specific mortality, which is mortality within a given age cohort. For example, infant mortality is the number of children who die in their first year of life per 1,000 live births.
Life expectancy is also a measure of mortality.
Migration
Migration is the movement of populations from one geographic area to another.
Emigration is when individuals leave a particular area.
Immigration is when individuals enter a particular area.
Internal migration is the movement of populations within a national boundary.
The trend in the U.S. has been for individuals from the Northeast and Midwest to move to the South and the West.
Additionally, in the U.S. and many other nations, there is a trend toward internal migration from rural areas to urban areas by migrants seeking economic opportunity, leading to depopulation of rural areas and increase in urban populations (see Chapter 10: Inequality and Social Change”).
This trend is called rural flight or rural exodus.
This trend was pronounced in the U.S. and Western Europe in the mid-20th century, and is prominent in China and sub-Saharan Africa in the early 21st century.
