The Study of Population

Introduction

• The population problem: overpopulation

  • Peaked in 1960/1970 → population growth faster than ever

  • Effects on environment

  • Result = decline in population + industrial capacity

• Highly developed countries: trouble = below-replacement birth rate + low population growth

  • Population aging

• Developing countries: decline in population growth

• Least developed countries: high growth rates → aggravates poverty, unemployment, slow economic development

• Demographers: those who study population dynamics

• Aggregate manifestations/measures

  • Birth rate

  • Death rate

• 3 fundamental variables of demography:

  • Fertility

  • Mortality

  • Migration

• Other variables:

  • Age

  • Sex

• Highly industrialized countries: below-replacement fertility rate

  • Baby boom generation

• Canada - urban expansion

  • More automobiles → greenhouse gas emissions → pollution

• Importance of population for society

Population Defined

• Population: a collectivity of people co-existing within a prescribed geographic territory at a given point in time. The collectivity changes as a function of the interplay of migration, birth, and death processes

• Temporal continuity: people living today are descendants of many earlier generations

• Demographic metabolism: a continuing process of societal renewal through the fundamental demographic processes of birth, death, and in- and out-migration

• Census: a tool allowing to count the number of persons present in a given area at a specified time

  → Undercount!

  • Can identify:

    • Civilian population

    • Total resident population

    • Total population living abroad

• Attrition: losses through deaths and emigration

• Accession: gains through births and immigration

Formal Demography and Population Studies

• Demography: the scientific study of population and how population is affected by births, deaths, and migration

  • Divided in 2 aspects that are complementary:

    • Population studies

    • Formal demography

• Roland Pressat’s 3 core areas

Formal Demography

• Formal demography: the quantitative study of population in terms of growth, distribution, and development/change

  • How many people of what kind are where?

Population Studies

• Population studies: interplay between demography and other disciplines

  • Focuses on identifying determinants and consequences

  • How come? So what?

The Nature of Demographic Change

• Static analysis: focus on demographic conditions at a fixed point in time

• Dynamic analysis: study the change in demographic conditions over a period of time

  • Process variables: variables that reflect human behavioral processes (fertility, mortality, migration)

Change in Population Size

• Net migration: the net difference between the number of incoming and outgoing migrants

• Demographic balancing equation

Linear, Geometric, Exponential, and Logistic Models of Population Growth

• Linear model: assumes a straight-line progression of change over time

  • The population grows by the same amount between time points

  • Rate of change is constant

• Geometric/Exponential models: assume that growth follows a non-linear trend over time

  • Geometric model: growth occurs at discrete time points, such as the end of each year

  • Exponential model: assumes continuous compounding at discrete time points

• Logistic model: assumes that a human population undergoing prolonged exponential growth will eventually experience insupportable levels of population density, which will impose strains on resources and the environment; and under such conditions, society would be compelled to implement measures to curtail growth or face increased rates of mortality

  • Small population + low population density = increase rate of growth

Compositional Change

• Compositional change: change in the distribution of key population characteristics (age, sex, marital status, education, occupation)

• Age-sex pyramid: a graphic representation of the distribution of the population in terms of age and sex

Individual Behavior and Demographic Processes

Individual State Transitions as Demographic Behavior

• Multistate classification: intersection of statuses

• State transitions: moving in and out of statuses

  • Repeatable

  • Non-repeatable

Individual State Transitions and Demographic Rates

• Rate: a dynamic, quantifiable measure of risk given exposure to some specific events over some specified interval

Reclassification Processes

• Reclassification: a change in identification by individuals

Demographic Change and Social Change

• Social change has occurred when a social pattern is significantly different from what it has been in the past

  • Agents of social change: acts of individuals + changes in population

  • Processes: process of imitation + action of the mass media

• Normative behavior: when a behavior becomes a standard form of behavior

Age, Period, and Cohort: The Mechanisms of Demographic Change

• Biological aging: passage through life from birth to death

• Chronological aging: passage through biological and calendar time simultaneously

• Birth cohort: individuals who are born during a specified time interval and pass through biological and chronological time together

• Timing: the age at which these events occur

• Intensity: the number of persons involved

• Period perspective: emphasis on some phenomenon occurring at a given point in time or time interval

Cohorts and Generations

• Generation: one generation of parents produces a new generation of children…

  • Encompasses different birth cohorts that experience some significant defining societal experience

• Baby boom generation