D EMOGRAPHIC T RANSITION M ODEL (DTM) AP Human Geography 2.1/ 2.2 R EVIEW Where are population clusters? Why do people live and not live in certain areas? What are the different types of population densities? What are CBR, CDR, NIR, TFR, IMR, life expectancy, doubling time? W HAT IS THE D EMOGRAPHIC T RANSITION M ODEL (DTM)? DTM examines the change in the population within any given country over time. DTM is broken down into 4 stages. Rates of growth/ decline vary from country to country. DTM is primarily affected by CBR and CDR. All countries are in some stage of the DTM. DTM: S TAGE 1- L OW G ROWTH WHAT? Low population growth rate (NIR) High birth rates High death rates WHY? Epidemics and plagues keep death rates high Food sources are uncertain (hunting and gathering, basic farming) Humans have spent most of history in Stage 1 (400,000 B.C. to 8000 B.C.) No countries are currently in Stage 1 P OPULATION G ROWTH OVER TIME DTM: S TAGE 2- H IGH G ROWTH WHAT? Death rates decline rapidly Birth rates remain the same This leads to rapid population growth WHY? People are still accounting for high death rates and making lots o babies! Increase in wealth leads to better sanitation, technology (farming), better overall healthpeople live longer! First countries entered Stage 2 during the Industrial Revolution (late 1700s, early 1800s) Europe/ N. America enter Stage s but does not reach Africa, Asia, Latin America until the 1950s (Medical Rev.) Currently, most of sub- Saharan Africa is Stage 2. DTM: S TAGE 3- M ODERATE G ROWTH WHAT? CBR drops rapidly, gets closer to CDR Population still grows, but much less rapidly TFR above 2.1 WHY? People decide not to have as many children (lower IMR, children are liabilities, not assets) European/ N. American countries moved from Stage 2 to 3 in the 1950s Some Asian/ Latin American countries moved from Stage 2 to 3 recently. (1980s/ 1990s) DTM: S TAGE 4- L OW G ROWTH WHAT? Death Rate and Birth Rate are very close/ NIR close to 0 (zero population growth) TFR around 2.1 WHY? Women enter labor force Birth control Increased income/ leisure time Most European/ NA countries have reached Stage 4. P OSSIBLE 5 TH S TAGE WHAT? Higher death rates than birth rates, irreversible population decline. TFR below 2.1