Yes I was born and raised in Philadelphia. My first friend's family moved to the suburbs (Cheltenham, Pa) when I was 10 in 1957. The rest of the them moved out to the suburbs before the the end of the 60,s. I still have family in the Pa suburbs. I am completely unfamiliar with anyone moving out of the city who is looking for a car free or even car-lite lifestyle , except for retirees in retirement communities.

The first gentrified area that I am familiar in Phila. is Society Hill and it was always high priced housing good for prosperous couples and totally unsuitable for raising children. My understanding of newer gentrified areas like Northern Liberties and near the Art museum are that they are mostly young professionals and hipster couples/groups who are the residents. Families with children and decent incomes look elsewhere including the Jersey suburbs.