"Does education reduce childbearing, or does childbearing get in the way of education?"

Assuming causation, which direction does it go?

"In theory, either scenario is plausible."

A girl born in a "pronatalist" environment might later revise her childbearing aspirations as the experience of schooling transforms her world views, access to contraception, bargaining power or economic opportunities. Conversely, a teen’s unexpected pregnancy might alter the costs and social support available for her pursuit of education.

Supposedly, a study shows "that women's childbearing patterns have a stronger impact on their education than the other way around." That may or may not be true, but one question is: Why is it helpful to know? I've often read that educating young women is the most effective way to control population growth. If that belief is not true, it would undercut enthusiasm for education in countries with overpopulation problems.

We spend so much money on education, and I wonder whether we do that because of the intrinsic value of education or because we believe it is a means to various ends that we like. If the latter, studies that unsettle (or crush) our beliefs threaten our commitment to education.