Alexandria, Va.Why do urban areas constantly get more expensive and exclusive? My neighborhood provides a clue. A proposed redevelopment of a single property in Del Ray, a much-loved part of Alexandria, recently died after a yearlong fight. The brouhaha, which divided the community, shows how the not-in-my-backyard mindset blocks virtually any increase in housing supply, even those that strive to maintain local character while making relatively modest changes.

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