Ignorance is Not Necessarily Bliss

A few years ago, I heard on the radio an interview with a long-experienced official from the World Health Organisation. His field was population control. He said that the only thing he'd seen that made any significant difference to the birth rate in poor countries was women's education.

A woman's educational level - best predictor of how many children she'll have.
Number of births per woman declines 40% in two decades.
Women's Education and Family Size in Selected Countries 1990s.