Urban sprawl has sparked a national debate over land-use policy. At least 19 states have established either state growth- management laws or task forces to protect farmland and open space. Dozens of cities and counties have adopted urban growth boundaries to contain development in existing areas and prevent the spread of suburbanization to outlying and rural areas. The Clinton administration has proposed to make urban sprawl a federal issue.

But much of the popular support for land-use activities at all levels is based on a poor understanding of real estate markets and of how much land is undeveloped.

• Only about 5 percent of the nation's land is developed and three-quarters of the population lives on 3.5 percent of the land.

• Farmland loss has been moderating since the 1960s, falling from a 6.2 percent decline in farmland per decade in the 1960s to 2.7 percent in the 1990s.

• More than 90 percent of the land in three-quarters of the states is rural, including forests, cropland, pasture, wildlife reserves and parks.

• Acreage in protected wildlife areas and rural parks exceeds urbanized areas by 50 percent.

Sprawl has been blamed for the decline of big cities and older, inner-ring suburbs. But many cities suffer from poorly functioning school systems, high tax rates, high crime rates, anticompetitive regulations and a deteriorating housing stock.

Some critics of low-density residential development say it increases pollution, congestion and natural resource use. They believe higher density development would mitigate those impacts. However, increasing population density does little to alleviate auto-caused smog and growth controls tend to accelerate the loss of open space in cities.

• More than 75 percent of commuter trips are by car in every area except New York -- and more than 90 percent are by car in most areas.

• Increased development density creates odd-shaped parcels and land that would ordinarily be left open is eventually developed.

Many planners have acknowledged that "bad planning" (for example, large-lot zoning) was a significant contributor to the urban sprawl they now want to eliminate. But there is little evidence government growth management is better suited than real estate markets and private conservation efforts to provide the kinds of housing and communities people want.

Source: Samuel R. Staley, "The Sprawling of America: In Defense of the Dynamic City," Policy Study No. 251, January 1999, Reason Public Policy Institute, 3415 S. Sepulveda Boulevard, Suite 400, Los Angeles, Calif. 90034, (310) 391-2245.