Yeah horrible parents or rich parents are really the two big reasons one can move out. Otherwise there’s really no reason to do it if you’ve got your whole support and friend network in the city.

It makes some sort of sense imo. What the graph is essentially saying is that most people stay in the same city as their parents. An 18 mile rage around a house covers most of a city. It’s probably thousands of people who live in the same neighborhood as their parents skewed by the handful that move out of their home city.