väestönvaihtelun

Väestönvaihtelu, also known as demographic transition, is a model describing the historical shift from high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system. This process is typically divided into distinct stages.

In the first stage, both birth rates and death rates are high, resulting in slow population growth. High mortality is often due to disease, famine, and poor sanitation. In the second stage, death rates begin to fall due to improvements in public health, sanitation, and food supply, while birth rates remain high. This leads to a period of rapid population growth.

The third stage sees birth rates start to decline, often due to increased access to education, urbanization, and the availability of family planning. Population growth slows down. In the fourth stage, both birth rates and death rates are low, leading to stable or even declining population growth. Some models include a fifth stage where the birth rate falls below the death rate, resulting in a population decrease.

The demographic transition is not a uniform process and can vary in speed and specific characteristics depending on the country and its socio-economic context. It has been a significant factor in shaping global population trends over the past few centuries.