It’s not surprising to me at all that this study by law professors Christopher S. Elmendorf and Douglas M. Spencer found PA to be the most prejudiced state outside the South.
At least in the South integration was attempted. In PA, the overreliance on local property taxes for school funding means you can still have a very wealthy white school district bordering one with mostly poor brown students. You can still have white townships effectively banning multi-family and affordable housing from white neighborhoods with zoning regulations. And of course the tiny tax bases of the 2562 municipalities do an excellent job of protecting white 1st and 2nd Class townships from having to share tax revenue with the older core cities where poorer browner people live. The effect of all these fragmented municipal and school tax bases and hyper-local zoning codes is to turbo-charge segregation in Pennsylvania: