Most “Smart Growth” planning reforms adopt as a core principle the goal of increasing housing affordability and diversity. This goal, in fact, is one of the leading justifications for limiting so-called “urban sprawl.” Low-density residential and commercial development, the argument goes, reduces the overall quality of urban life by increasing congestion, promoting social isolation and segregation, and inefficiently using land. More compact higher density land-use patterns, sprawl opponents continue, would improve the quality of life for most people and produce a richer range of housing choices at affordable prices. Centralized land-use planning at the state, regional, and local levels, tied to statewide planning goals, is often promoted as the solution. More than a dozen states have adopted statewide growth-management legislation using this general framework, including states as diverse as Florida, Oregon, Washington, Maine, and Tennessee.