An overview of the factors that influence human population growth and distribution, including birth rates, death rates, migration patterns, and demographic transitions.
Introduction to Human Population Dynamics
Key concepts, drivers, and implications for societies and the planet
| Term | Definition |
|---|---|
| Population dynamics | The study of how human numbers change over time and space, and the factors that cause those changes. |
| Demography | The statistical science that measures population size, structure (age, sex, etc.), and vital events (births, deaths, migration). |
| Population growth rate | The net change in population size per unit time, usually expressed as a percentage per year. |
Fertility (Births)
Mortality (Deaths)
Migration
Population Structure
| Stage | Fertility | Mortality | Population Growth | Typical Societies |
|---|---|---|---|---|
| 1. Pre‑transition | High & variable | High & variable | Low or stagnant | Pre‑industrial, agrarian |
| 2. Early transition | Declining | Rapid decline | Rapid increase | Early industrialization |
| 3. Late transition | Low | Low | Slowing increase | Mature industrial economies |
| 4. Post‑transition | Very low (often < 2.1) | Low | Near‑zero or negative | Highly developed economies |
| 5. (Proposed) | Below replacement, possibly rising again due to policy | Low | Decline, aging population | Some European & East Asian nations |
Key drivers: improvements in public health, nutrition, education (especially of women), and economic development.
Exponential Growth (idealized, no constraints)
[
P(t) = P_0 e^{rt}
]
Logistic Growth (growth limited by resources)
[
P(t) = \frac{K}{1 + \left(\frac{K-P_0}{P_0}\right) e^{-rt}}
]
Cohort‑Component Method (most common projection technique)