Read the article titled "politics and population." what factors contributed to the development of population policies during the 20th century?

The development of the population policies in the 20th century were due too multiple factors, the most important of which were:

- Fertility rates were starting to lower down, especially in the ''western world'' in the second half of the 20th century.
- Increased demand for labor force.
- The World Wars, especially the second one caused huge migration movements.
- Millions of people from less developed countries were trying to migrate to more developed countries in search of a better life.

Answer decreased soil salinity;

He got it right defiantly right