[eixample]

The problem with some of these NYC to Philly migration estimates is that you can move from an outer NYC metro suburb to a slightly farther out suburb and end up in the Philadelphia metro (say Bucks County). Not sure if that is what is going on here.

The city of Philadelphia does have a lot of potential to gain from NYC but needs to improve it's city business tax structure in order to really do so. Amtrak improvements and reliability also could go a long way.

From the little I can see, I think a lot of row homes are being bought by NYC real estate investors who are priced out of the market up there and there are certainly a lot of NYC to Philly migrants. Hard to say if it is more than a trickle and makes up for out migrants though.