Population principle

Population principle refers to some basic laws and regulations of population change, including population growth rate, birth rate, mortality rate, population flow and population structure.

The principle of population can help us understand the phenomenon of population and its relationship with social economy and environment.

1. Population growth rate

The population growth rate refers to the proportion of the increased population in a specific period to the total population at the beginning of that period. According to the growth rate, population changes can be divided into three types: natural growth, negative growth and population transfer. In the past few hundred years, especially in the twentieth century, the population growth rate has shown a rapid growth trend.

2. Birth rate

Birth rate refers to the average number of newborns per thousand people in a specific period. Birth rate is usually regarded as an important part of population growth, because the increase of birth rate will directly lead to the increase of natural growth rate. With the development of social economy and the change of people's concept, the birth rate in different countries presents different trends.

3. Mortality rate

Mortality refers to the average number of deaths of thousands of people in a specific period. Unlike the birth rate, the death rate is usually regarded as an important factor in population decline. At first, the mortality rate was mainly affected by infectious diseases, natural disasters and other factors, but with the continuous improvement of science and technology and medical level, the mortality rate in all countries in the world has improved obviously.

4. Population mobility

Population mobility refers to the phenomenon that people move from one place to another. Population mobility can be divided into two types: domestic migration and international migration. Population mobility often leads to changes in population structure and socio-economic structure, as well as the emergence of resources and environmental problems.

5. Population structure

Population structure refers to the distribution of population by age, sex, occupation, etc. The demographic changes are of great significance, such as aging, employment pressure, marriage and family problems. Accurately grasping the changing trend of population structure is very important for social development and government management.

In a word, the population principle is some basic laws and laws that describe the law of population change, including population growth rate, birth rate, mortality rate, population flow and population structure. It is of great significance to understand and predict the development trend of population phenomenon and solve related social and economic problems.