The United Nations Population Fund says changing demographics, mainly in Africa and Asia, may allow for rapid economic growth if there is sufficient investment in young people.

The agency said Tuesday that a "demographic dividend" that happens when a country's working age population is larger than its dependent elderly and young is possible.

In its State of World Population 2014 report it said this may happen in about 60 primarily African and Asian countries.

Executive Director Babatunde Osotimehin said it is likely there will never again be such potential for rapid economic and social progress.

The agency said the demographic dividend could lift hundreds of millions of people out of poverty and allow economies to expand.

It recommended sustained investment in education and health programs for young people.