New York City has devoted far more resources to the development and rehabilitation of affordable housing than any other U.S. city, investing more than $4 billion from 1986 to 1997. This article surveys the impact, status, and implications of New York's housing programs. It looks at correlations between publicly funded housing starts and changes in the housing stock, welfare rolls, and crime and at the economic impact of the city's housing investments within low-income neighborhoods. New York's housing programs have transformed neighborhoods, replacing large swaths of abandoned shells and vacant land with new housing and preserving thousands of buildings at risk of abandonment. While these housing investments correlate most strongly with reductions in vacant units and vacant lots, they also show significant correlations with reductions in welfare rolls and violent crime, but uneven economic impacts as well. New York's housing programs are important nationally less for the specifics of particular programs than for the institutional collaborations on which they are founded.