zahavasdad – Look at the numbers of Kollels in Lakewood, East Ramapo and the Five Towns. That will explain everything.
It isn’t the number of families moving in, it is the number of large families who aren’t making anything near what they “need” and are on government support (but still manage to own a home (HUD), or if not, pay for taxes indirectly via increased rent).
The Five Towns (I imagine) has more working families with fewer children and less poverty.