Overview
This lecture explains the Demographic Transition Model (DTM), focusing on its limitations when applied to modern global population trends.
Origins and Structure of the DTM
- The DTM describes population changes in four original stages based on Western Europe and U.S. data.
- It assumes all countries follow the same pattern of declining birth and death rates as they industrialize.
Limitation: Stages Beyond the Original Model
- Demographers suggest a fifth stage where birth rates fall below death rates, causing population decline (e.g., Japan).
- Stages beyond stage 5 are hypothetical and not universally accepted.
Limitation: Ignoring Migration
- The DTM does not account for immigration and emigration impacts on population totals.
- Germany’s population has grown due to immigration despite negative natural increase since the 1970s.
- Classifying a country’s DTM stage becomes difficult when migration skews population trends.
Limitation: Global Pandemics and Climate Change
- The model does not factor in global events like pandemics or climate disasters.
- Events such as HIV/AIDS in South Africa and COVID-19 can cause non-standard changes in birth and death rates.
- Climate change may increase migration, death rates, and disrupt industrialization, challenging DTM predictions.
Limitation: Variable Fertility Trends
- The model predicts gradual fertility decline, yet modern birth rates can change rapidly for diverse reasons.
- Birth rates in Hong Kong fell quickly due to rapid industrialization and government policies.
- Some countries, like Namibia, experience stalled birth rates linked to contraception use.
- Other cases, such as Spain and China, show divergent trends because of local policies or crises, not just industrialization.
DTM in a Globalized World
- Modern globalization, cultural exchange, political policies, and international aid produce complex trends not captured by the original DTM.
- The DTM can be too simplistic and rigid for today’s interconnected world.
Key Terms & Definitions
- Demographic Transition Model (DTM) — A model describing changes in birth, death, and population growth rates as countries develop.
- Natural Increase — The difference between birth rate and death rate in a population.
- Net Migration — The difference between immigration into and emigration from an area.
Action Items / Next Steps
- Review case studies on Japan, Germany, South Africa, Hong Kong, Namibia, Spain, and China for real-world DTM limitations.
- Prepare to discuss how globalization and policy can shape demographic trends beyond the DTM predictions.