The itemized bill for staying
Houses on this island ran about ×4.2 from 1990 to 2025 (FHFA HPI Nassau 72→300, Suffolk 75→316). Incomes ran about ×2.9 (SAIPE).
About 322k Long Island 18–34 live in a parent's house (ACS B09021, ~56% vs ~32% US). Island 65+ went 324,616 (1990 census) → 597,366 (2025 PEP). Drinking water sits on a 1978 sole-source aquifer.