2.4-2.5

• demographic balancing equation - used to describe the future population of a region of any scale:

  future population = current population + (number of births - number of deaths) + (number of immigrants - number of emigrants)
• immigrants - people who migrated into the country

  emigrants - people leaving the country
• crude birth rate (CBR) - number of live births per year per 1000 of the population
• total fertility rate (TFR) - number of children a woman has in her lifetime during her child bearing years
• infant mortality rate - the number of deaths of children under one year of age per 1000 live births
• crude death rate (CDR) - number of deaths per 1000 population per year
• rate of natural increase (RNI) - the percent change in the population each year, calculated by subtracting the CBR by the CDR then divided by ten
• population doubling time - the time it takes for the population to double in size
• demographic transition model(DTM) - shows the five typical stages of population change that countries experience as they modernize
• Characteristics of the DTM stages


  • Stage 1: High Stationary
  • Stage 2: Early Expanding
  • Stage 3: Late Expanding
  • Stage 4: Declining
  • Stage 5: Declining
• Stage 1: High Stationary

  • High birth rate
  • High but fluctuating death rate
  • Natural increase 0 to .5%
  • Very low population growth
  • Very young population structure
• Stage 2: Early Expanding

  • High but fluctuating birth rate
  • High but fluctuating death rate
  • Natural increase 5 to 4%
  • Rapid growth as death rates fall faster than birth rates
  • Very young population structure
• Stage 3: Late Expanding

  • Declining birth rate
  • Declining but not as fast as previous stage death rate
  • Natural increase 4 to 8%
  • Rapid but slowing growth as birth rates decline
  • Young, with rising life expectancy
• Stage 4: Low stationary

  • Low but enough to keep population stable birth rate
  • Low and stable death rate
  • Natural increase .8 to 0%
  • Very low growth because births and deaths are both low
  • Balanced, with more aging
• Stage 5: Declining

  • So low it falls below the death rate birth rate
  • Low, sometimes increasing as the population ages death rate
  • Natural increase 0% to (-1%)
  • Very low decline as births fall below deaths
  • Very old population structure
• Stage 5: Declining

  • Japan
  • Germany
• Stage 4: Low Stationary

  • United States
  • China
• Stage 3: Late Expanding

  • Mexico
  • Turkey
  • Indonesia
• Stage 2: Early Expanding

  • Mali
  • South Sudan
• Stage 1: High Stationary

  • Scattered isolated groups (like the Amish, indigenous tribes, etc.)
• demographic momentum - this process occurs because even though fertility rates have declined, people are living longer, and this results in population continuing to grow for another 20-40 years
• epidemiological transition model - the model that describes the changes in health status of populations over time
• Epidemiological Transition Model Stages

  • Disease and Famine
  • Receding Pandemics
  • Degenerative and Human-Created Diseases
  • Delayed Degenerative Diseases
  • Reemergence of Infectious and Parasitic Diseases
• Stage 1: Disease and Famine

  Parasitic or infectious diseases, accidents, animal attacks, or human conflicts cause most deaths. Food insecurity makes famine more common and more devastating
• Stage 2: Receding Pandemics

  The number of pandemics (widespread diseases that affect large populations) declines as a result of improved sanitation, nutrition, and medicine
• Stage 3: Degenerative and Human-Created Diseases

  Infectious and parasitic diseases continue to decrease, but diseases associated with aging-such as heart disease and types of cancer-increase as people live longer
• Stage 4: Delayed Degenerative Diseases

  Stage 4 is an extension of Stage 3, but the age-related diseases are put off as medical procedures delay the onset of these diseases through advanced procedures. Diseases such as Alzheimer's and dementia increase
• Stage 5: Reemergence of Infectious and Parasitic Diseases

  Infectious and parasitic diseases increase as some bacteria and parasites become resistant to antibiotics and vaccines
• Effects on Population

  • Stage 1: A high death rate and low life expectancy
  • Stage 2: A decreasing death rate and increasing life expectancy
  • Stage 3: Death rate stabilizes at a low level and life expectancy increases
  • Stage 4: Death rate reaches its lowest level and life expectancy reaches a peak
  • Stage 5: Life expectancy decreases