OBJECTIVE Students will analyze demographic transition models, population pyramids, and epidemiological stages in order to predict a nation’s development.

Replacement Fertility refers to a total fertility rate of 2.1 children per woman (in late stage 3/stage 4 countries), which equates to the average number of children each woman is required to have for a population to replace itself in the long term, without migration

Demographic Transition Model Stage 1 : Low Growth Stage 2 : High Growth Stage 3: Moderate Growth Stage 4: Low Growth Stage 5: Population Decline

Demographic Transition in England Fig. 2-14: England was one of the first countries to experience rapid population growth in the mid-eighteenth century, when it entered stage 2 of the demographic transition.

Stage 1: Low Growth Huge variation in CDR and CBR making the NIR essentially zero Hunter gatherer population First Agricultural Revolution War and disease No such country exists today

Case Study: England Stage 1 1066 – Normans invade Population 1 million By 1750, population = 6 million Unpredictable Population: 1250 = 4 million 1350 = 2 million

Demographic Transition in England Fig. 2-14: England was one of the first countries to experience rapid population growth in the mid-eighteenth century, when it entered stage 2 of the demographic transition.

Stage 2: High Growth After 1750, worlds population grows 10 x faster than any other time Industrial Revolution Early countries that entered stage two Medical Revolution Most recent countries entering stage 2

Stage 2: England (1770- 1880) 1750 – CBR AND CDR were both 40 per 1,000. 1800, CBR was 34 but the CDR = 20. 1770 = 6 million 1880 = 30 million NIR over period = 1.4 %

Demographic Transition in England Fig. 2-14: England was one of the first countries to experience rapid population growth in the mid-eighteenth century, when it entered stage 2 of the demographic transition.

Stage 3 : Moderate Growth CBR rapidly declines Why? Choice Social custom Urban Life CDR continues to decline NIR becomes more modest

Stage 3: England Moderate Growth 1880s -1970 CBR – 33 per 1000 CDR – 19 per 1000 1970 CBR – 15 per 1000 CDR – 12 per 1000 Average NIR over the period of 0.7 per year with an overall increase in pop from 26 – 49 million

Demographic Transition in England Fig. 2-14: England was one of the first countries to experience rapid population growth in the mid-eighteenth century, when it entered stage 2 of the demographic transition.

Stage 4 : Low Growth CBR and CDR declines to the point that NIR approaches zero ZERO POPULATION GROWTH CBR might still be higher than CDR because females die before reaching stage of fertility These countries tend to have stronger economies higher levels of education better healthcare higher proportion of working women Fertility rate hovering around replacement rate

Stage 4 : England England = currently in stage 4 Changes in CBR is due to the maturation of society not the change in personal decisions of women Growth attributed largely to immigration

Demographic Transition in England Fig. 2-14: England was one of the first countries to experience rapid population growth in the mid-eighteenth century, when it entered stage 2 of the demographic transition.

Stage 5: Population Decline Countries in which fertility rates have fallen significantly below replacement level (2.1 children) Elderly population is greater than the youthful population.

Demographic Transition

Criticism of the DTM… Industrialization is difficult to achieve for LDC’s in a trading system that protects the industries of MDC’s. The model assumes that reductions in fertility are a function of increased wealth and industrialization.

Criticism of the DTM… The model is an over-generalization of the industrialized European experience; Model is too rigid in assuming all countries proceed from stage 1-5; it ignores variables and exceptions (eg. War, political turmoil);

Population Pyramids Demonstrates two major components of a country’s population (1) population by gender (2) population by age (5 year intervals)

Developing Nation

Developed Nation

Population Pyramids Each Demographic Stage has a distinctive population structure percentage of population by age group Distribution of males and females

Population Pyramids Both can be displayed on a population pyramid Percentage of each age group in 5 year increments Divided by male and females along the horizontal

Shape of the Pyramid Determined primarily by the CBR Stage 2 = large base of the pyramid

Shape of the Pyramid Determined primarily by the CBR Stage 4&5 = wider top with a transition toward a rectangle

Sex Ratio Number of men per 100 women Slightly more males than females born Males have higher death rates Women start to outnumber men at age 40

Dependency Ratio Dependents on the society Primarily those too old and young to work Divide the country into three groups 0-14 years 15-64 years 64 years and older

Dependency Ratio Developing Countries: 1:1 ratio Larger percentage of young dependents Strains ability to provide adequate schools, hospitals, and day care

Dependency Ratio Developed Countries: Need adequate income and medical care after retirement Have established means of providing those things Economic strain to maintain them based on a smaller tax base

EPIDEMIOLOGICAL TRANSITION (1) Stage of Pestilence and Famine (2) Stage of Receding Pandemic (3) Stage of Degenerative Diseases (4) Stage of Delayed Degenerative Diseases (5) Stage of Reemergence of Infectious and Parasitic Diseases

(1) Stage of pestilence and famine Infectious and parasitic diseases = primary cause of human deaths General lack of modern medical understanding of transmission of diseases manner of preventing/treating the spread of disease. i.e. plague

(2) Stage of receding pandemic Pandemic  disease that occurs over a wide geographic area and affects a very high proportion of the population In this stage, improved sanitation, nutrition, and medicine reduced the amount of pandemics but could not eliminate them Birth of the modern medicine investigation i.e. cholera

(3) Stage of degenerative and human created diseases Decrease in the amount of deaths from infectious diseases Chronic diseases associated with aging cardiovascular diseases cancer Previously categorized as natural causes Associated with the spread of the medical revolution, especially in stage 3 locations.

(4) Stage of delayed degenerative diseases Medical research focused on treating (but not necessarily curing) degenerative diseases.

(5) Reemergence of infectious and parasitic disease Three reasons for emergence of stage 5 evolution/mutation of diseases Resistance to modern medicine continued poverty in many areas of the world Infectious diseases continues to exist in many parts of the world despite attempts to eradicate them improved travel and interaction between those areas of poverty.