Population and Urbanization Chapter 15

Population Change https://www.youtube.com/watch?v=ozDskXxmdDI

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 15-44 for women Fertility looks at the actual number of births occurring to women from fecundity (biological capacity to bear children)

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

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

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

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)

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.

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

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

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

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.

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

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

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.

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

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.

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

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

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

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