The most important problem of population are given by Warren S. Thompson as under.
- What are the changes `that takes place in the size of population and how are these changes brought about?
- Where the people found and what are the changes taking place in their distribution in communities and other areas?
- What kind of people are found in any given population group and how one given population group and how one population group is different from the other population group?
So, in short, the main problems of population are the size, distribution and the traits of population which are studied by the social demography and demographers.