MANAGING FUTURE POPULATION growth and its accompanying development is a very controversial issue in much of the nation. If a metropolitan area grows rapidly, where should its new residential and commercial structures be located?

There are two extreme and conflicting approaches to this issue. The sprawl-tolerant approach would let future growth continue at low densities in the open countryside around already settled areas. Few people openly advocate this view because sprawl, which critics complain generates too much driving and air pollution, is so unpopular.

But in essence, many people support more sprawl, because they reject the main alternative, which is the anti-sprawl or smart-growth approach. Its proponents want to contain future growth either within or around settled areas through devices such as urban growth boundaries, utility service districts, major infill developments and setting aside open space. In my opinion, neither of these visions will prevail entirely. Instead, some elements of each will occur.

Local Governments Make The Call

In the 1990s, 29 metropolitan statistical areas (MSAs) grew by more than 250,000 people. All had populations of more than 1 million, and 17 contained more than 2 million. These are the areas likely to experience strong pressure for outward expansion in the current decade.

In these regions and elsewhere, the major decisions about where to locate future growth will be made by local, suburban governments — not national, state or regional authorities. The voting populations of suburban areas are dominated by homeowners, and their primary political goal is to implement policies that protect the market values of their homes.

Most homeowners believe construction of any nearby housing at higher densities or lower costs than their own dwellings might reduce their home values. Hence, they pressure their local governments to adopt exclusionary policies emphasizing relatively costly low-density, single-family units. This creates a dynamic in fast-growing, suburban areas that pushes growth outward in continued sprawl.

But experience shows there is a lot of room for growth within close-in suburban counties, even in highly exclusionary metropolitan areas. The San Francisco Bay Area provides a striking example. From 1980 to 2000, 61% of the population growth in the 11-county region was in the four close-in suburban counties: San Mateo, Santa Clara, Alameda and Contra Costa. The counties comprised 63% of the region's total 2000 population.

Yet even in 2000, the average population density in those counties was only 1,524 persons per square mile, compared with 16,863 in San Francisco County, which contains only the city of San Francisco itself. So there is still plenty of room for more growth within those close-in counties — if local governments and their constituents are willing to permit it. Data from the Atlanta MSA show a similar situation, even though that region has far more permissive zoning and fewer topographical obstacles to development than the San Francisco Bay Area. From 1980 to 2000, 61% of the total population growth in the Atlanta MSA occurred in the suburban portions of four close-in counties. Yet in 2000, those four counties (excluding the city of Atlanta) had an average density of only 1,573 persons per square mile, compared with Atlanta's 3,160.

Sprawl Will Not Disappear

Based on this data and other evidence, I predict that a lot of the future growth in fast-growing regions will occur within settled, close-in counties and will not require much additional outward expansion. On the other hand, statistics show that almost 40% of the growth in both the Bay Area and Atlanta regions from 1980 to 2000 took place in outer suburban counties.

So my second prediction is that a significant amount of additional peripheral sprawl will continue in nearly all fast-growth regions.

This mixed result probably will make both pro-sprawl and anti-sprawl proponents unhappy. So my third prediction is that nearly all people interested in managing future growth more effectively will remain severe critics of what actually happens, since it will not resemble their ideal outcomes.

Anthony Downs is a senior fellow at the Brookings Institution in Washington, D.C.

The views are those of the author and not necessarily those of officers, trustees or other staff members of the Brookings Institution.