Migration
Migration is the third demographic force. It is measured as stock — how many people live outside their country of birth — and as flow — how many move each year.
Stock
Migrant stock counts how many foreign-born people live in a country at a point in time. It is a snapshot of accumulated movement and is the primary UN DESA international migration indicator.
Flow
Migration flow counts how many people move in or out over a period. Net migration — inflow minus outflow — is what directly changes a population, alongside births and deaths.
Net migration rate by region
| Region | Net migration (per 1000) | Direction |
|---|---|---|
| Africa | -0.5 | Strong growth |
| Europe | 1.5 | Long-term decline |
| Asia | -0.2 | Near peak / plateau |
| Northern America | 2.5 | Moderate growth |
| Central & South America | -0.8 | Near peak / plateau |
| Middle East / Western Asia | 0.5 | Moderate growth |
| Oceania | 3.0 | Moderate growth |
Migration contribution to total change
In several European countries net migration now exceeds natural change as the source of population growth. In some Gulf states migrants make up the majority of residents. Understanding whether a population is growing because of births or because of arrivals is essential to interpreting demographic continuity.
Primary international source: UN DESA Population Division — International Migrant Stock.