The Impact of Opportunity Zones on Housing Supply ⋆

U.S. housing supply remains severely constrained. We estimate the causal effect of Opportunity Zone (OZ) designation on the stock of active and vacant residential addresses using HUD’s aggregated USPS Address Vacancies data and modern difference-in-differences designs. OZ designation produced a large, sustained supply increase in designated low-income tracts, with an estimated effect of over 416,000 additional active/vacant addresses through 2025Q1, averaging 47.5 addresses per treated tract. Effects largely reflect new development, not reallocation from nearby non-OZ areas, showing placebased capital-gains tax incentives can stimulate private investment that increases local housing supply.