Glossary
Demographic Transition Model (DTM)
A theoretical framework that describes how populations change over time, based on shifts in birth rates and death rates, typically moving through five stages.
Example:
Understanding the Demographic Transition Model (DTM) helps geographers explain why countries like Germany have an aging population while Niger has a very young one.
Epidemiological Transition Model (ETM)
A model that describes the changing causes of death and disease patterns in a population as it undergoes demographic and socioeconomic development.
Example:
The Epidemiological Transition Model (ETM) helps explain why infectious diseases were the primary killers centuries ago, while chronic diseases are more prevalent today.
Infant Mortality
The number of deaths of infants under one year old per 1,000 live births, often used as an indicator of a country's healthcare and living conditions.
Example:
A significant decrease in infant mortality is a hallmark of a country transitioning from Stage 1 to Stage 2 of the Demographic Transition Model.
Life Expectancy
The average number of years a person is expected to live based on current mortality rates, reflecting overall health and development within a population.
Example:
Improvements in healthcare and nutrition have dramatically increased global life expectancy over the past century, allowing more people to live into old age.
Natural Increase Rate (NIR)
The percentage by which a population grows in a year, calculated as the crude birth rate minus the crude death rate, usually expressed as a percentage.
Example:
A country with a high Natural Increase Rate (NIR), like many in Sub-Saharan Africa, will experience rapid population growth and a very wide base on its population pyramid.
Population Pyramids
Bar graphs that show the age and sex composition of a population, providing insights into a country's demographic structure and DTM stage.
Example:
A population pyramid with a wide base and narrow top indicates a rapidly growing population, typical of a country in Stage 2 of the DTM.
Pro-natalist policies
Government policies designed to encourage higher birth rates, often implemented in countries facing population decline or an aging workforce.
Example:
France's offering of generous parental leave and childcare subsidies is an example of pro-natalist policies aimed at boosting its birth rate.
Stage 1: High Stationary (DTM)
The initial stage of the DTM characterized by high birth rates and high death rates, resulting in very slow or stagnant population growth.
Example:
Historically, before the agricultural revolution, human societies were largely in Stage 1: High Stationary (DTM), with frequent famines and diseases keeping populations stable.
Stage 1: Pestilence and Famine (ETM)
The initial stage of the ETM where infectious and parasitic diseases, along with famine and malnutrition, are the primary causes of high mortality.
Example:
In Stage 1: Pestilence and Famine (ETM), a widespread outbreak of cholera could decimate a community due to poor sanitation and lack of medical knowledge.
Stage 2: Early Expanding (DTM)
A stage in the DTM where death rates rapidly decrease due to improvements in sanitation, nutrition, and healthcare, while birth rates remain high, leading to rapid population growth.
Example:
When a country enters Stage 2: Early Expanding (DTM), you often see a significant drop in infant mortality as basic medical care becomes more accessible.
Stage 2: Receding Pandemics (ETM)
A stage in the ETM where the incidence of infectious diseases declines significantly due to improvements in public health, sanitation, and medical advancements.
Example:
The widespread adoption of vaccines and clean water systems marked the shift into Stage 2: Receding Pandemics (ETM) for many nations, drastically reducing deaths from diseases like smallpox.
Stage 3: Degenerative and Human-Created Diseases (ETM)
The stage of the ETM where chronic, non-communicable diseases associated with aging and lifestyle, such as heart disease and cancer, become the leading causes of death.
Example:
As people live longer, a country moves into Stage 3: Degenerative and Human-Created Diseases (ETM), where healthcare systems focus more on managing conditions like diabetes and hypertension.
Stage 3: Late Expanding (DTM)
The stage of the DTM where birth rates begin to decrease significantly due to factors like urbanization, industrialization, and increased access to education and family planning, while death rates remain low.
Example:
As women gain more educational and economic opportunities, a country often transitions into Stage 3: Late Expanding (DTM), with families choosing to have fewer children.
Stage 4: Delayed Degenerative Diseases (ETM)
An advanced stage of the ETM where life expectancies are extended further due to medical advancements that delay the onset or improve the treatment of chronic degenerative diseases.
Example:
Breakthroughs in chemotherapy and surgical techniques allow many individuals to survive cancer for longer, illustrating the characteristics of Stage 4: Delayed Degenerative Diseases (ETM).
Stage 4: Low Stationary (DTM)
A developed stage of the DTM characterized by low birth rates and low death rates, resulting in a stable or very slow-growing population.
Example:
Many highly developed nations, such as Canada, are in Stage 4: Low Stationary (DTM), facing challenges related to an aging workforce rather than rapid population expansion.
Stage 5: Declining (DTM)
A hypothetical or emerging stage of the DTM where birth rates fall below death rates, leading to a negative natural increase rate and a shrinking population.
Example:
Countries like Japan are experiencing Stage 5: Declining (DTM), prompting government initiatives to encourage higher birth rates to counteract population shrinkage.
Stage 5: Reemergence of Infectious Diseases (ETM)
A potential or emerging stage of the ETM where infectious diseases reemerge or new ones appear, often due to antibiotic resistance, global travel, and persistent health disparities.
Example:
The global spread of drug-resistant tuberculosis highlights the challenges faced in Stage 5: Reemergence of Infectious Diseases (ETM), where old threats return with new virulence.
Total Fertility Rate (TFR)
The average number of children a woman is expected to have during her childbearing years, a key indicator of population growth potential.
Example:
A country with a Total Fertility Rate (TFR) below 2.1 is likely to experience population decline in the long term, assuming no net migration.