Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 8: Population Dynamics in Historical Comparative Perspective -…
Chapter 8: Population Dynamics in Historical Comparative Perspective
Population Growth
There were only 5 million people on earth in 8000 BCE
By 1750, there were still fewer than a billion
Some periods saw Europe and North America experiencing rapid growth while little or no growth occurred in Africa
Demographic transitions
The occurrence of prolonged and relatively permanent changes in population growth rate
Demographic Transition and Social Change
The Four Stage Process
Prior to the colonial era, growth rates did not vary across the world
Growth was equally slow and erratic on all continents
The exceptional cases were urban settlements and their hinterlands
1750 AD saw a shift to a population explosion
Demographic Transition
Dramatic and relatively sudden transformation in a population's growth rates
When one change is followed by another, transition can be divided into stages
From Stage 1 to Stage 2
Stage 1: Low population growth rates because of high mortality
Despite equally high levels of fertility
Death reigned and affected every aspect of human existence
Large number of children necessary for family survival
Stage 2: Began in mid 17th century
Two important advances were made
The founding of modern science by Sir Isaac Newton
The widespread introduction of the earliest modern technologies of Mortality Control
Population explosions occurred
Early World Population Growth
10 million people 12,000 years ago
7 million in 4000 BCE
By 1,000 BCE, the human population rose to 50 million
The next 1,000 years to 1 AD, improved sanitation and agriculture techniques had their impact
The population increased rapidly to somewhere between 170 and 400 million
For the next 1,000 years, world population growth was slow and irregular
From Stage 2 to Stage 3
From 1875 onward, growth rates have been in decline
The third, downward stage was due to an intentional decrease in fertility
People took control of the force of natality
Family planning resulted from a value shift of the middle classes
It became acceptable and more accessible
Pronatalism
The view that having many children is the most virtuous practice
From Stage 3 to Stage 4
Europe has now completed its demographic transition full-circle
Its growth is now slow, uneven, and rates are zero or below like before 1650
Real possibility that birth rates will fall below death rates
Demographic Transition in the Less-Industrialized Countries
Asia's population doubled once
Africa's population doubled twice
Latin America experienced the most dramatic population fluctuations
As Europe progresses through stage 2 , the rest of the world remained at stage 1
The Prospects of Future Population Growth
By 2050, the world's population should be double in size from 1990
By 2150, the world will reach ZPG
Accompanying these increases will be certain geographic redistribution
Less-industrialized nations' share of the world's total will increase
The Redistribution of the World's Population
In Asia, Africa, and Latin America, mortality rates continue to decline much faster than birth rates
The population in theses regions are very younng
Life expectance in the world increased from 61 to 67 between 1980 and 2010
Population Momentum
Populations grow for years even if fertility falls below replacement level
The Third Stage in the Less-Industrialized Regions
We assume stage 3 is the destiny of nations in stage 2
No scientific theory would allow for law-based predictions
Many African nations have completed the second stage without any apparent movement toward the third
Success and failure can help in selecting policy options in population education, foreign assistance, family planning, and public health initiatives
Gemeinschaft to Gesellschaft (agrarian community to an industrial society)
Europe's Second Transition
It was believed that stage 3 would be indefinitely long and stable
During the Great Depression, fertility fell below replacement level
The baby boom refuted forecasts of population collapse
Subsided in the early 1960s
Second Demographic Transition
Accompanied by changes in the rates of marriage, divorce, and cohabitation
Unlike occasional wars and depressions, value shifts toward self-centeredness and structural improvements in the status that women are relatively permanent
The Aging of the World's Population
Major demographic consequence of fertility decline is an older population
The outcome of steady decreases in the proportion of young persons
More than half of the billion greater than 55 years live in less-indutrialized areas
People age 60 worldwide can expect to live 20 years or more
The elderly population is expected to triple by 2050
Measures and Models of Growth
Difference Method
Simpler and cruder measurement of population growth
Components method
Looking at growth by the influence of births, deaths, in and out migration
Measuring Growth by Difference
All changes in the size of a population is "growth"
Negative growth or zero population growth
G = Pt - Po
Percentage growth is (G/Po) x 100
Linear Growth Model
"Arithmetic growth"
Assumes equal percentage of persons added to a population every year
r = (percentage growth) / n
Exponential Growth Model
"Geometric increase"
Increases slowly at first and then accelerates as the population base grows
r = [ ln (Pt / Po) ] / n
Doubling Time
Expressed in years instead of rates or percentages
Number of years it would take for a population to double in size
Solve for n in the equation for exponential growth, assuming that Pt is is twice Po
Growth by Components
Fundamental Equation: G = ( B-D ) + ( I-O )
( B-D ) is natural increase
( I-O ) makes up net migration
The U.S. Population: Growth and Change
The exception to the rule: United States
Natural increase is far higher than almost all of Europe
The only industrialized country projected to be among the 12 most populous nations by midcentury and to remain from the top 12 in 1950
800,000 immigrants entering each year
Birth rate is also much higher than Europe's
Incipient Decline
Used to describe the third stage of Europe's demographic transition, suggesting potential future population loss