The working-age population refers to the segment of the population that is typically considered to be of working age, typically ranging from 15 to 64 years old.

A declining fertility rate means that fewer children are being born, which leads to a decrease in the proportion of young people in the population and an increase in the proportion of older people.

The age dependency ratio is a measure of the proportion of the population that is not of working age and is dependent on the working-age population for support.

An increasing labor force participation rate means that more people are working or actively seeking work, which contributes to a larger and more productive workforce, leading to faster economic growth.

The youth dependency ratio is a measure of the proportion of the population that is of working age relative to the proportion that is not of working age.

A rising dependency ratio means that there are more people who are not working and relying on government support, which can strain the government's resources and make it more difficult to provide social welfare programs.

An aging population refers to a situation where a significant portion of the population is 65 years of age or older.

As people age, they are more likely to experience health problems and require healthcare services, leading to an increase in demand for these services.

A demographic dividend refers to a situation where a large proportion of the population is of working age, creating a favorable condition for economic growth.

A demographic dividend can lead to faster economic growth due to the increased availability of labor and the potential for higher productivity.

A youth bulge refers to a situation where a large proportion of the population is of school age, typically between the ages of 15 and 24.

As the proportion of young people in the population increases, there is a corresponding increase in the demand for education services, such as schools, colleges, and universities.

A fertility surge refers to a situation where there is a rapid increase in the birth rate, leading to a larger proportion of the population being of childbearing age.

As the proportion of children in the population increases, there is a corresponding increase in the demand for goods and services related to children, such as toys, clothing, and education.

Demographic inversion refers to a situation where the proportion of the population that is of retirement age exceeds the proportion that is of working age.