Re: Leader-follower model (and permanent difference). I took it as a representation of the two theories mentioned in the introduction as to whether the differential in fertility by education would be transient and disappear (end of leader-follower), or if it would remain even at the end of the transition (permanent difference). Bongaarts mentions that "some analysts" (Jeffery and Basu, Lutz and Goujon, Cleland) think the differential would disappear, but that "conventional wisdom ... leads one to expect that educational differences in fertility will remain....". I wonder if Bongaarts intended "conventional wisdom" to be a dig at the others' theory? I tried to look up Jeffrey and Basu, and it looks like there may have been some evidence that a leader-follower model may fit some countries, but I didn't have a ton of time and it's hard to find the full text.