Topic 2 The Attributes of Populations

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Topic 2 The Attributes of Populations

• A Population Growth
• B Fertility
• C Mortality
• D Population Profiles
• E Population Capacity

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Conditions of Usage

• For personal and classroom use only
• Excludes any other form of communication such as
  conference presentations, published reports and
  papers.
• No modification and redistribution permitted
• Cannot be published, in whole or in part, in any
  form (printed or electronic) and on any media
  without consent.
• Citation
• Dr. Jean-Paul Rodrigue, Dept. of Economics
  Geography, Hofstra University.

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A. Fertility

• 1. Fertility, Birth and Death Control
• 2. Population Growth Rates
• 3. Doubling Time

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1. Fertility, Birth and Death Control

• Definition
• Process during which the population of an area
  increases.
• Related to a complex economic, cultural and
  social environment.
• Two factors
• (1) Number of births exceeds the number of
  deaths.
• (2) Migration flow is positive.
• Over 70 of the United States annual population
  growth results from immigration.
• Expressed in percentages.
• Birth rate of 20 per 1000 people.
• Death rate of 10 per 1000 people.
• Growth rate of 10 people per year per 1000
  population, or 1.

Births minus Deaths
Positive migratory balance
Population Growth
Society
Economy
Culture
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Top Ten Contributors to World Population Growth,
1995-2005
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1. Fertility, Birth and Death Control

• Achieved death control more effectively then
  birth control
• Major factor behind the growth of the global
  population in recent decades.
• Modern medicine
• Vastly decreased the number of deaths from many
  diseases (malaria, yellow fever, etc.).
• Famine
• Reduced through better agriculture, distribution,
  storage and by international aid mechanisms.
• Infant mortality
• Decreased in most areas.
• Improvement in the availability and quality of
  the water supply
• Improved hygiene conditions.
• Decreased deaths caused by water borne diseases.

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1. Fertility, Birth and Death Control

• Birth control has been more difficult to achieve
• Reproduction cannot be effectively planned by
  the state.
• Religious beliefs.
• Cultural traditions.
• The importance of children as help, labor and
  security.
• The role of women is very limited in many
  societies.

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2. Population Growth Rates
High
2.0
Average
1.0
Low
0.0
ZPG
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3 Scenarios of Global Population Growth, 2005-2050
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Population Growth Rate, 2000
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Population Change between 2000 and 2050 ()
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Population of Russia, Japan Italy, 1950-2050 (in
millions)
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3. Doubling Time

• Definition
• Length of time necessary for an area (usually a
  nation) to double its population.
• The mathematics of population work very much like
  compounding interest.
• Percentage of increase is applied to an
  ever-increasing base.
• Simple equation 72 / Growth rate.
• Implications
• The faster the growth rate the lower the doubling
  time
• 1 growth rate 72 years.
• 4 growth rate 19 years.
• Infinite doubling time no growth or negative
  growth.

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Doubling Time as of 2000
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B. Fertility

• 1. Crude Birth Rate
• 2. Total Fertility Rate
• 3. Factors Influencing Fertility

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1. Crude Birth Rate

• Crude Birth Rate (CBR) or General Fertility Rate
  (GFR)
• Number of live births per year per 1000
  population.
• Both males and females are considered.
• All the population is considered, even the
  non-reproductive segment (children, elderly).
• Numbers like 10, 20, 40, etc.

25 males of any age
25 females of any age
10 children born that year
1,000
30
CBR 30
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2. Total Fertility Rate

• Total Fertility Rate (TFR)
• Number of live births per female of reproductive
  age (15-49).
• Numbers such as 2.2, 4.5.
• Indicates population change over a long period of
  time.
• Instructive about societal norms in any given
  culture.
• A TFR of 2.1 is considered as being the
  replacement birth rate.
• Lower than 2.1 yields population decrease while
  rates greater than 2.1 yields population
  increase.
• Improvements in medical conditions lower the
  replacement rate (below 2.06 in many countries).

25 females between 15-49
10 children born that year
1,000
60
TFR 2.04 (60/1,000) (49-15)
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Total Fertility Rate, 1995-2005
Replacement rate (2.1)
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TFR among Developed Countries, 2005
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3. Factors Influencing Fertility
Biological Determinants
Social Determinants
Fertility
Economic Determinants
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3. Factors Influencing Fertility

• Biological determinants
• Age
• Reproductive age of women ranges from 15-44 or
  from 15-49.
• Men 13-??
• Health and nutrition
• Poor health and/or nutrition can reduce
  fertility.
• Linked with underweight children.
• Linked with child mortality rates.
• Environment
• Represents an undocumented impacts on fertility.
• Stressed populations tend to have less males than
  females.
• Possible correlation between sperm count and
  pollution.

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Birth Rate per Age Group, United States, 1965,
1990, 2002 (per 1,000 women)
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Average Sperm Count of Americans, 1938-98 (per ml)
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3. Factors Influencing Fertility

• Social determinants
• The social norms and acceptance of practices
  affecting fertility.
• Differ from society to society.
• Marriage
• Particularly the average age of marriage.
• The percentage of people never married varies
  spatially and affects fertility rates.
• Late marriage age generally involves less
  children.
• Contraception
• Used by 30-50 of all married couples.
• Availability of contraceptive devices and social
  attitudes toward their use affect fertility
  rates.
• Sharp differences exist between DCs and LDCs.
• Some notable exceptions, such as China and Cuba.

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Girls between 15 and 19 who are Married, Divorced
or Widowed, 2004
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3. Factors Influencing Fertility

• Abortion
• Last resort measure when contraception failed (or
  was not used).
• Its legality is not universal and under challenge
  in some countries where it is permitted.
• Global figures (1999)
• 210 million pregnancies.
• 22 of all pregnancies end up in a abortion.
• 46.2 million abortions, of which 20 million
  procedures are obtained illegally.
• Illegal abortions are common in most societies
  where it is prohibited.
• Culture plays an important determining role in
  the impact of abortion.
• United States 49 all pregnancies unwanted and
  about half of unwanted pregnancies ended in
  abortion (1.4 million abortions per year).

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Pregnancies and Abortions per Women Aged 15-19
Years, 1998
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3. Factors Influencing Fertility

• Economic determinants
• The role of children, or their value affects
  fertility.
• Inverse relationships
• Fertility and income per capita.
• Fertility and urbanization.
• Traditional rural societies
• Children still play an important economic role
  and contribute to family wealth.
• Fertility is likely to remain higher.
• Industrial and post-industrial societies
• Costs tend to increase with the development level
  of the society.
• Deflate the fertility rate since parents must
  consider the direct and opportunity costs of
  bearing additional children.

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3. Factors Influencing Fertility

• Direct costs lost
• For the support of children.
• Food, clothing, housing, education, etc.
• Estimated to be between 150,000 and 290,000
  from birth to 17.
• Opportunity costs lost
• Lower standard of living.
• Reduce the ability to save and invest.
• Labor force participation of women is affected by
  child-bearing.
• Relationship between inflation and fertility?
• Increase in the cost of living may have an impact
  on fertility.
• Particularly if both parents must work to support
  the family.
• In the United States, the costs that have
  increased the most
• Housing.
• Professional services (e.g. healthcare and
  education).
• Energy.

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3. Factors Influencing Fertility

• Dysgenics
• The Idiocracy Syndrome controversial concept.
• In the past, successful individuals were
  rewarded with more descendants
• Evidence that in England, up to the 1850s,
  wealthy individuals had more children.
• The welfare state appears to have reversed the
  situation
• The poorest and the least successful tend to have
  more children.
• Negative correlation found between fertility and
  IQ.
• At the global level
• The poorest societies tend to have the highest
  fertility.
• International aid enables dysfunctional economies
  to endure.

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C. Mortality

• 1. Crude Death Rate
• 2. Infant Mortality Rate
• 3. Life Expectancy

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1. Crude Death Rate

• Death rate
• Easiest of the variables to consider.
• Occurs just once per person and is the most
  recorded.
• Crude Death Rate (CDR)
• Annual number of deaths per 1000 population (all
  ages included).

25 males of any age
25 females of any age
10 people who died that year
1,000
30
CDR 30
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1. Crude Death Rate

• Causes of death
• Throughout most of history famine, epidemics, and
  wars have been the leading causes of death.
• Primary causes of death began to shift to
  degenerative problems related to aging.
• These include such factors as heart disease and
  cancer.
• Death and welfare
• Used to be considered a sign of the health of a
  population.
• Different age structures among the populations of
  different countries.
• Possible for a nation with high living standards
  to have a higher death rate than a poorer nation.
• Reason overall older population.

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Crude Death Rate, 2000
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Fertility and Mortality in the United States,
1950-2004 (in 1000s)
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2. Infant Mortality Rate

• Definition
• Expressed in numbers of deaths of infants under
  one year per 1000 live births of the same year.
• Also considers the death of children under 5 per
  1000 in their cohort.
• High levels of infant mortality pull down life
  expectancy rates.
• Reflects the quality of the health system.
• Very strong differences between developed and
  developing countries.

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Infant Mortality Rate, 2000
38
Causes of Death for Children under 5 in
Developing Countries
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3. Life Expectancy

• Definition
• Number of years a person is expected to live.
• Based on current death rates.
• Does not necessarily apply to current generation.
• May change due to ameliorations in standards of
  living.
• Context
• Strong geographical variations in life
  expectancy.
• Half a century ago, most people died before the
  age of 50.
• Global average life expectancy reached 66 years
  in 2006.
• Several achievements and failures
• Economic development has benefited human health.
• Improvement in diet and sanitation.
• Urbanization may have adverse effects.

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3. Life Expectancy
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3. Life Expectancy

• Factors behind higher life expectancy
• About 40 years was gained in the 20th century.
• 90 of the reduction in the death rate occurred
  before the introduction of antibiotics or
  vaccines.
• Major factors (33 years)
• Improved sanitation (for food and water).
• Reduction in crowding.
• Central heating.
• Sewer systems.
• Refrigeration.
• Improved health (7 years)
• Mainly medical technology.
• Small share attributed to drugs.
• Modern medicine a sham?

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Life Expectancy at Birth, 1910 and 1998
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World Average Life Expectancy, 1950-2005
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of Men and Women Expected to Survive to Age 80,
by Region (Among people born 1995-2000)
45
Yearly Cost of a 1,000,000 Life Insurance
Premium, 2001
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3. Life Expectancy

• Optimum life expectancy
• Life expectancy is ultimately dictated by human
  physiology
• At some points, organs cease to function
  properly.
• Limit on the lifespan of non-cancerous human
  cells.
• Nearing life expectancy limits
• Even if age-related diseases such cancer, heart
  disease, and stroke were eradicated, life
  expectancy would only increase by 15 years.
• Currently around 76 years.
• Expected to reach 85 years in most developed
  countries by 2030.

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D. Population Profiles

• 1. Population Pyramid
• 2. Dependency Ratio
• 3. Sex Structure

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1. Population Pyramid

• Definition
• Graph showing the breakdown of each sex by age
  group (cohort).
• Illustrates a nations population structure.
• Shows the male/female composition of the
  population.
• Most of the time, the breakdown involves 5 years
  periods.

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60-75
Females
Males
45-60
30-45
15-30
0-15
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Population Pyramid of Mexico, 2000
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Population Pyramid of Sweden, 2000
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1. Population Pyramid

• Mexican pyramid
• Much wider base than the others.
• Beginning of transition.
• Rapidly growing population where the percentage
  of people under 15 years of age is high.
• Swedens pyramid
• Does not appear to be a pyramid at all.
• Youngest component is smaller than its
  middle-aged population and only slightly larger
  than its aged population.
• No-growth situation, since some deaths occur from
  all age groupings.
• Sweden has a higher death rate than Mexico.

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Population Pyramid of the United States, 2000
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1. Population Pyramid

• USA pyramid
• Intermediate situation
• Aging population.
• Large amounts of recent immigration.
• Bulge in the 30-54 year old component
• The baby boom generation.
• Small numbers in the 55-65 year old component
• Low birth rates during the 1930s and during WW
  II.
• Dip in 20-29 segment of the population
• Low birth rates during the 1970s and early 1980s.
• Limited immigration.
• Preponderance of women at the top of the pyramid,
  an indication of their longer average life span.

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Population Pyramid, Berlin 1946
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1. Population Pyramid

• German pyramid
• Shows the most extreme example of population
  decline.
• Vast difference between males and females in the
  upper age groups.
• Vast number of military casualties among the
  population which fought the WWII.
• Significant impacts in the post WWII labor market.

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2. Dependency Ratio

• Definition
• Comparison between the productive and
  non-productive population.
• Non-productive population
• Refers to the very old (usually gt65 years of age)
  and the very young (usually lt15).
• Considered to be the non-productive segments of
  society because they are not part of the labor
  force.
• Productive population
• Between 15 and 65.
• This portion of the population constitutes the
  labor force.
• Revised to consider lower than 20 years in
  developed countries (increasing time spent for
  education).
• Ratio (lt15) (gt65) / (15-65) 100

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2. Dependency Ratio

• Implications
• Society incurs costs in supporting its dependent
  population.
• Old age generates social costs
• Retirement benefits.
• Increased medical expenditures.
• USA 12 of the population over 65 60 of health
  care costs.
• Greater consumption of other social services.
• Youths
• Some medical costs.
• Great expenditures for education.
• National budgets often reflect these
  expenditures.
• Linked with the population pyramid
• Pyramidal distributions have high dependency
  ratios.
• Rectangular distributions have high dependency
  ratios.
• Transitional pyramids have low dependency ratios.

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Dependency Ratio, World, 1950-2050
59
Dependency Ratios in G-7 Countries, 2000-2050
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2. Dependency Ratio

• Aging
• Population over 65 years
• 2005 477 million (7.3).
• 2020 719 million (9.4).
• 2050 1,492 million (16.2).
• Impacts
• Social security costs
• Demographic changes may bankrupt the system.
• Not a saving but a pay as you go system.
• Requires a large working age population to be
  sustainable.
• Medical costs and the medical industry at large.
• Public sector funds such as the federal budget.
• Goods and services used by the elderly.
• Local impacts (school districts).

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Population 60, Industrial and Developing
Countries, 1950-05, With Projections to 2050
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Percentage of the Population between 15 and 65,
2000
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2. Dependency Ratio

• Impacts
• Social security costs
• Demographic changes may bankrupt the system.
• Not a saving but a pay as you go system.
• Requires a large working age population to be
  sustainable.
• Medical costs and the medical industry at large.
• Public sector funds such as the federal budget.
• Goods and services used by the elderly experience
  increasing demand levels.
• Those used by the young and/or middle aged will
  decline in relative importance.
• Local impacts (school districts).

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Coverage and Actuarial Balances of Current Public
Pension Systems USA, Japan and China
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3. Sex Structure

• Definition
• Gender composition of a population.
• Males / Females 100.
• Probability
• Approximately equal probability of male and
  female births.
• Normally expect sex ratios to remain very close
  to 100.
• This is often not the case.
• Factors
• Life expectancy at birth is greater for females
  (79 years) than for males (72).
• Gap has increased steadily since 1920, when the
  difference was just one year.

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Sex Ratio (males per 100 females), 2000
67
Sex Ratio in the United States, 1820-2005 (males
per 100 females)
WWI
WWII
Civil War
Immigration Boom
Life expectancy gap
Immigration Boom
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E. Population Capacity

• 1. Population Density
• 2. Population Distribution
• 3. Population Capacity

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1. Population Density

• Arithmetic density
• Relates the size of a population (P) to the area
  which contains it (A).
• Number of people per square mile or square
  kilometer.
• Without regard to the productive quality of the
  area.
• Distributional imbalances.
• Physiological density
• Number of people per unit of productive land.
• Productive is generally equated with arable land
  (AL).
• Important figure to measure sustainability.

AD P / A
Arable land
PD P / AL
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Density Measures for Selected Countries, 1995 (in
people per square mile)
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2. Population Distribution

• Definition
• Considers the distribution of population
  densities over the earths surface.
• Informative in assessing a nations population.
• Typical concentrations along major river systems.
• Areas of great concentration
• South Asia.
• East Asia.
• Western Europe.
• Northeastern North America.
• Empty areas are attributed to
• Harsh physical landscapes.
• Harsh temperature.

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World Population Density and Distribution, 1995
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3. Population Capacity

• How many people can be sustained by the Earth?
• Based on human choices and natural constraints.
• Maximum density.
• Quantity of arable land.
• Agricultural technology.
• Harvesting the ocean.
• Human facilities.
• Availability of resources (energy, construction
  materials, etc.).

Space
Technology
Consumption
Resources
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3. Population Capacity

• Demographic capacity
• Studies about natures capacity to support human
  life go back many centuries.
• Leeuwenhoek (1679) extrapolated densities for
  Holland to the whole planet (13.4 billion
  capacity).
• Focus
• Space.
• Energy requirements.
• Non-renewable resources.
• Photosynthetic potentials.
• All are based on the same principle
• Tracing resource and energy flows through the
  human economy.

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3. Population Capacity

• Ravenstein in 1891
• Concept of carrying capacity.
• Focused on the earths cultivable areas, and
  their potential productivity given increases in
  yields over time
• Fertile 200 people / km2.
• Steppe 10 people / km2.
• Desert 1 person / km2.
• Figure of 6 billion people as the number Earth
  could sustain without lowering living standards.
• Reached this number in 1999.

Arable land
X
Agricultural technology
/
Consumption per capita
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3. Population Capacity

• Contemporary issues
• Events such as the Green Revolution were not
  foreseen by Ravenstein.
• Managed to increase agricultural yields in many
  areas by quantities far greater than he had
  anticipated.
• Efforts to calculate carrying capacity have
  largely failed.
• Too many variables.
• Value ranges between 4 and 16 billion.

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3. Population Capacity

• Level of consumption
• Alternative perspective.
• The issue is not resource supply, but resource
  demand.
• The world is producing only a finite number of
  resources for consumption.
• Demographic capacity is linked with level of
  resource consumption.
• American (lifetime)
• 1 million kg of atmospheric waste.
• 10 million kg of liquid waste.
• 1 million kg of solid waste.
• 700,000 kg of minerals.
• 24 billion BTU of energy.
• 25,000 kg of plants.
• 2,000 animals (28,000 kg).

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3. Population Capacity

• Ecological footprint and biocapacity
• Try to assess the demand of human activities on
  the environment.
• Transformed over an unit of surface.
• Footprint (2003) 2.2 hectares per capita.
• Biocapacity (2003) 1.8 hectares per capita.
• Net deficit, in theory.
• May be overestimating the footprint because of
  CO2 sequestration assumptions.

Area
Population
X
X
Consumption per person
Bio-productivity
X
Footprint intensity


Biocapacity(Supply)
Ecological Footprint (Demand)