A presumed result of education is that young girls will pursue economic opportunities and postpone marriage and childbirth until later. But that outcome failed to materialize in Malawi. Rather than delay a family—which would usually be an indicator of economic progress—the result was static. Before the free-education policy, the median age for childbirth was 18.9. A generation later, it was unchanged, despite the fact that the average woman’s schooling had doubled. What’s more, the girls who continued their education and graduated from secondary schools were giving birth now at a younger age than before the free-schooling policy.

What happened in Malawi, according to the study’s author, Monica Grant, is that the flood of students overwhelmed the education system, and quality declined so dramatically that the average literacy rate decreased from what it had been before free education.

“Just increasing education in and of itself is not necessarily going to change behaviors in the way we thought, though quality might have,” said Grant, an assistant professor of sociology at the University of Wisconsin-Madison who has been working in Malawi since 2006. “That’s the real twist: What is education actually able to deliver to the students who are having opportunities to learn?”