The researchers referenced in the above post in connection with a study they did, indeed are writing for The Urban Institute.

I see no reference to either one of them claiming to be nonpartisan politically (I'm assuming that's your "nonpartisan" reference).

I'm just wondering how you came to the conclusion they they were.

Not a big bone of contention, but just curiosity.

You can go off on a righteous fit if you want, but this is an honest question.