Lecture Notes: Demographic and Epidemiologic Transition Models

Introduction

• Changing narrative on global population:
  • U.S. fertility rates are declining.
  • Some countries face population decrease concerns.
  • Other regions, like Nigeria, are experiencing population growth.
• By 2050, Nigeria is expected to become the third most populous country.
• Africa's population is growing at 2.7% annually.

Demographic Transition Model (DTM)

• Stage 1: High CBR (Crude Birth Rate) & CDR (Crude Death Rate)

  • Low NIR (Natural Increase Rate) due to births and deaths canceling.
  • Characteristics: Lack of sanitation, medicine, high subsistence agriculture.
  • Migration for food.
  • No countries currently in Stage 1.

• Stage 2: Industrial & Medical Revolution

  • Decrease in CDR but high CBR leading to population growth.
  • Improved medicine, agriculture, and food surplus.
  • Migration to urban areas for economic opportunities.
  • Example: Afghanistan.

• Stage 3: Decline in CBR and CDR

  • Urban living reduces need for large families.
  • Higher life expectancy, decreasing infant mortality.
  • Gender roles shift, more economic participation by women.
  • Examples of countries: Mexico.

• Stage 4: Low CBR & CDR

  • Low to flat NIR.
  • ZPG (Zero Population Growth) possible.
  • Economic and cultural factors reduce family sizes.
  • Examples: United States, China.
  • Policies can influence stages (e.g., China's one-child policy).

• Stage 5 (Speculative): Negative NIR

  • Population decline due to low birth rates.
  • Example: Japan, Germany.

Epidemiologic Transition Model

• Associated with stages of DTM but focuses on causes of death.

• Stage 1: Pestilence and Famine

  • High mortality from diseases, pandemics, food shortages.

• Stage 2: Receding Pandemics

  • Improved medicine and sanitation reduce death rates.

• Stage 3: Degenerative Diseases

  • Longer life spans lead to deaths from heart disease, cancer.

• Stage 4: Delayed Degenerative Diseases

  • Medical advances increase life expectancy.
  • Lifestyle changes can lead to health issues (e.g., obesity).

• Stage 5: Re-emergence of Infectious Diseases

  • Disease evolution, poverty, and globalization spread diseases (e.g., COVID-19).

Conclusion

• Importance of understanding both models in AP Human Geography.
• Encouragement to practice and utilize resources for further learning.