Aging and Society
first stage of demographic transition
-High birth and high but fluctuating death rates -Wars, famine, and disasters take heavy tolls
second stage of demographic transition
-Industrialization -Falling death rates due to medical advances and food storage - High birth because large families are still considered good
Proportion Aged
A very straightforward measure of population aging that sets a clear threshold for people to meet to be counted as older. Usually set at 65, 60 in nations with lower life expectancy. This measure is easier to take put less valuable when it comes to study
Factors of population aging
Birth Rate, Mortality Rate, and Migration
fourth stage of demographic transition
Low birth and death rates stabilize populations. because some developing nations may already be suffering too much from the impacts of large populations to replicate the developed world's transition.
The Fallacy of the Demographic Imperative
One key to avoiding errors in interpretation is to keep in mind that demography is not destiny.
Median Ages
The median is the midpoint of a range of numbers—the point at which half the cases fall above and half below. Single numbers that are often used in conjunction with other measures of population aging.
Population Pyramid
a graphic illustration of the age and sex structure of a population that shows the percentage or number of people within a total population that fits into selected age and sex categories. -Three basic shapes/models persist 1. The true pyramid, or fast-growth shape, is characteristic of young countries with high fertility and high mortality, such as Kenya. 2. The rectangular, or no-growth, pyramid shows the effects of sustained very low fertility and very low mortality, as in Denmark. 3. The third classic pyramid shape is a slow-growth, beehive-shaped pyramid that represents a transition between the true pyramid and a rectangle. , this shape reflects a pattern of low mortality and fertility i.e the United States. 4. The inverted pyramid is the no-growth model sustained over a long period of time. The most desirable distribution shown in these charts varies per nations individual needs.
prospective age
average number of remaining years of life for a person
fifth stage of demographic transition
birth and death rates are low but the birth rate has fallen below the margin of replacement leading to a shrinking population.
third stage of demographic transition
birth rate drops towards the death rate and growth rate decreases to either a low or zero growth rate
Dependency Ratios
measure the proportion of a population that falls within age categories traditionally thought to be economically dependent: traditionally those under age 15 (the youth dependency ratio) and over age 64 (the aged dependency ratio). -The proportion aged in society is simply the number of older people divided by the total population. - The aged dependency ratio is the number of older people divided by the number of people ages 15 to 64.
Causes of Unnatural demographic shifts
political turmoil, natural disasters, epidemics, and food shortages that might have befallen a country with an unusual demographic pattern.
How populations age
population aging occurs when large numbers of people survive into old age and relatively few children are born.
Life Expectancy
the average experience of a population. It is calculated from actual mortality data from a single year and looks at what would happen to a hypothetical group of people if they moved through their lives experiencing the mortality rates observed for the country as a whole during the year in question..
Replacement level fertility
the number of children a couple must have to replace themselves (2.1 developed, 2.7 developing)
demographic transition theory
the theory that links population aging to a two part transitional cycle that see's the birth rate out pace the death rate causing a lag between them. - Is highly variable on a nations level of development
