NY (along with a few other northeast cities) is somewhat unique in that of people who have kids and then move to the suburbs nearby, which I assume is a pretty

NY (along with a few other northeast cities) is somewhat unique in that of people who have kids and then move to the suburbs nearby, which I assume is a pretty significant demographic, a lot of them end up in other states like NJ and CT. But this same cohort pretty much anywhere in, say, California or Texas would not leave the state. Plus there are a lot of schools in NY and a lot of people go to them from far away, which doesn't count in this graphic, but then a bunch of those people move back home after school which does count. And there's a question of how they treat people who move around multiple times, some people probably move away for a few years then come back. Overall because of all the confounding factors, this really isn't a very interesting graph. States seem like a pretty arbitrary split when thinking about this, it would make a lot more sense to be looking at cities.