(Population Trends: DTM Models) Geo 2024

Unit 3

The Origin of the DTM model

-A model which works to show the various stages stages of population through the Industrial Revolution and Present (since 1929)

→ based on historic birth and death trends

-Model does not account for migration

DTM Stage: 1) HIGH STATIONARY

1. Birth Rate =  High

2. Death Rate = High 

3. Natural Increase = Low to zero - fluctuating 

4. Reasons for Pattern = Wars, pandemics, agricultural (large families = workforce), high infant mortality, inadequate sanitation and health care 

5. Country Examples = all countries up to 1800s

DTM Stage: 2) EARLY EXPANDING

1. Birth Rate =  High 

2. Death Rate = Decreasing 

3. Natural Increase = High

4. Reasons for Pattern = Modern medicine introduced - “germ theory of disease,” (infant mortality rate = decreasing), improvements in agriculture and sanitation, education 

5. Country Examples = Guatemala, Palestine, Yemen 

DTM Stage: 3) LATE EXPANDING

1. Birth Rate =  Decreasing 

2. Death Rate = Low

3. Natural Increase = High but decreasing 

4. Reasons for Pattern = Increase in women’s status, education and birth control, improved medicine 

5. Country Examples = Jamaica, India

DTM Stage: 4) LOW STATIONARY

1. Birth Rate =  Low

2. Death Rate = Low

3. Natural Increase = Low to Zero 

4. Reasons for Pattern = Stronger economy, healthcare, education, working women, fertility rate = 2 or lower 

5. Country Examples = Most developed countries

DTM Stage: 5) DECLINING

1. Birth Rate =  Low 

2. Death Rate = Low (but higher than birth rate)

3. Natural Increase = Decreasing 

4. Reasons for Pattern = Aging population, population policies (Ex. china’s one-child policy), some growth due to net migration rates 

5. Country Examples = Germany

TRICK QUESTION ABOUT POPULATION: How many children does one need to have to increase the population?

a couple needs 3 kids to add to the population → replaces two parents, plus one more → steady increase