The demographic transition is a theory that describes the transition from high birth rates and mortality rates to low birth and mortality rates, occurring as a part of the economic development of a country from a pre-industrial to an industrialized economy.

This transition explains the shift from initial low population growth to an explosive population increase, which is followed by a steady decline in growth.

In countries which have gone through deindustrialization, which is defined as a transition from manufacturing industries into service and information based industries, the birth rates have actually fallen below the death rates. Examples of such countries are Sweden, Italy, and Japan. In these countries, there is a natural decrease in the population as birth rates have fallen below the death rate.