1. Population and Urbanization
Chapter 15

2. Population Change

3. Population Change Size and Structure of Population
Birthrate – annual number of live births per 1,000 members of a population
Crude birth rate looks at the total population, including men, children, and women who are past child bearing years.
Childbearing years typically span for women
Fertility looks at the actual number of births occurring to women from fecundity (biological capacity to bear children)

5. Population Change Death rate – number of deaths within a society
Crude death rate does not take into account the varying death rates among subgroups of a population.
Infant mortality rate is the number of deaths among infants under the age of one year per 1,000 live births in a population.
This give a general measure of overall health and quality of life in a society.
Life expectancy refers to the average number of years a person born in a particular year can expect to live

7. Population Change
Migration rate – annual difference between in-migration and out- migration.
Migration is the movement of people from one specified area to another.
The effects of the migration rate is not as significant as birth and death rates

8. Population Change
Migration occurs due to what demographers call push and pull factors.
A push factor is something that encourages people to leave an area
Ex- religious/political persecution, famine, racial discrimination
A pull factor is something that encourages people to move to a certain area
Religious/political freedom, economic opportunities, higher standard of living

9. Population Change
Growth rate – the rate at which a population is increasing
Birth rates, death rates, and migration rates all affect the size of a population
The growth rate in more developed countries (industrialized countries) are typically lower than growth rates in less developed nations (lower levels of technology)

10. Population Change
Doubling time is the period of time in the terms of number of years it takes for a population to double in size, given the its current rate of growth
For example the population in the world doubled from half a billion to 1 billion between 1650 – 1850 in a span of 200 years.
then it doubled again between 1850 – 1930 by reaching 2 billion in a span of 80 years.
Less 50 years later it doubled to 4 billion by 1975
It is estimated that by 2025 the population will be 8 billion.

11. Population Change
Population composition – age and sex of the population
Demographers use a population pyramid to represent the age and sex distribution of a population
The graph is usually shaped like a pyramid because it ranges from the youngest at the bottom to the oldest at the top

13. Population Change
Explaining Population Change and Controlling Population Growth
Malthusian Theory – geometric population growth but arithmetic food production, population growth could outpace food production.
Demographic Transition Theory – lower birth rate and lower death rate as a result of a higher stage of technological advancement.
Controlling Population Growth – family planning and economic improvements

14. Population Change Demographic Transition
Stage 1 : preindustrial agricultural societies, both birth rate and death rate are high due to no means of birth control, low standard of living, and lack of medical technology
Stage 2: industrial societies, high birth rates and low death rates due to medical technology, sanitation, and food production.
Stage 3: fully developed industrial economies, low birth rates and death rates due to use of birth control, high standards of living, and medical advancement

15. Population Change
Zero population growth sometimes occurs at stage 3 due to nearly equal birth and death rates.
Some countries have even fallen below zero growth rate due to birthrates being less than death rates, thus population shrinkage.

17. Population Change Controlling population growth
Family planning is the conscious decision by couple to only have a certain number of children
reducing the number of unplanned pregnancies due to effective birth control
Some countries use antinatalism to reduce population growth
China’s one child policy
Economic improvements such as better health, higher levels of education, and higher income lead to lower birthrates

18. Urban Growth Evolution of the city and urbanization
Cities arouse with the agricultural revolution and preindustrial cities were small
Different occupations were located in distinct sectors and people were usually segregated into classes or castes
Unsanitary conditions led to high death rates
Daily living was built around kinship and governments were organized monarchies or oligarchies

19. Urban Growth
During the industrial revolution people came to cities in search of jobs
Commerce became the focal point of life in the industrial cities.
Central business districts including stores, offices, and banks replaced the segregated trade quarters of the preindustrial cities
Social life also changed during industrialization, the family had less power and singles gained independence.

20. Urban Growth
According to sociologists, urbanization has contributed to the rise in a number of social problems.
Crime, overcrowding, and pollution all increased as cities grew larger
Overurbanization occurs when more people live in a city than can be supported in terms of jobs and facilities
Inadequate housing, sewage disposal, and medical services
This is a problem in Latin America, Asia, and Africa

21. Urban Growth
Today 75% of Americans live in urban areas and almost every region of the country is heavily urbanized
Urbanization in more developed nations has generally followed an ordered progression and has resulted in increased rates of literacy, greater economic opportunities, and better health care.

22. Urban Growth
Urban ecology is the approach that examines the relationship between people and the urban environment
Urban ecologists argue that human behavior determines the layout of the urban environment and human behavior
Sociologists have developed 3 models to describe these patterns:
Concentric zone model
Sector model
Multiple nuclei mdoel

23. Urban Growth Models of cities
Concentric Zone Model – city spreads outward from the center, resulting in a series of circles or zones.
Sector Model – city growth in wedge-shaped sectors outward from the center the edges of the cities.
Multiple Nuclei Model – city develops around several centers of activity or a “nuclei” devoted to specialized land use

24. Urban Growth
Urban sprawl is characterized by poorly planned development of the edge of cities and towns
Residents who live in the downtown areas in the urban ecology model tend to be home to low-income residents
Recently there has been a reverse in migration from the suburbs to the city

25. Urban Growth Theories of city life
Anomie theory – city is anonymous and unfriendly and carries negative consequences for its residents
Compositional theory – greater diversity of city residents leads to a greater variety of lifestyles
Subcultural theory – people can find others with similar interests in diverse cities, some form close ties