A report from the United Nations Population Fund has said that investing in women's health makes countries richer because of a newly-identified "demographic bonus".

The bonus occurs when countries invest in areas like family planning and safe childbirth as well as traditional economic infrastructure.

As women are empowered to make choices, the report argues, fertility rates decline. The proportion of dependent children relative to the productive working population therefore also declines and economic growth follows.

The report also says that while countries like India appear to be heading for a demographic bonus, the poorest 50 states of the world, many in Africa, will require outside help if they are to benefit from the phenomenon. The poorest will not reach the economic take-off point where the bonus kicks in because they do not have the money to invest in women's health even though they know it would be a profitable investment.