Why the fertility gap between north and south Nigeria matters

To fly from the south to the north of Nigeria takes only a couple of hours. Yet in one way, it is like going back in time. In Lagos state, the commercial capital in the south, women can expect to give birth to an average of 3.3 children during their lifetimes, which is what the world’s fertility rate was in 1990. In Katsina state in the north, the fertility rate is, at 7.4, higher than the global rate was in 1800.