Mid-Decade Data Sharpen View of Mid-Size Suburbs

Immigrants continued to flock to most mid-size communities in Washington's outer suburbs over the first half of the decade, although the foreign-born population declined slightly in a few immigrant strongholds such as Baileys Crossroads, Annandale and Herndon in Virginia, and Silver Spring, Greenbelt and North Bethesda in Maryland, according to figures released by the U.S. Census Bureau yesterday.

The findings were included in the bureau's first-ever mid-decade publication of detailed social, economic and housing data on locations with as few as 20,000 to 64,999 residents.

Previously such wide-ranging statistical portraits of the nation's 2,500 mid-size counties, cities and towns were available only through the once-a-decade census, because that was the only count that provided a large enough sample on which to base estimates.

This year, the bureau overcame that problem by combining three years of responses to the recently launched American Community Survey, which collects information from more than 250,000 households a month and will replace the long-form questionnaire previously used in the decennial census.

Yesterday's release, which covers the 2005-2007 period, encompasses a dizzying array of issues, including income, marital status, language ability, commuting habits, housing costs, occupation and type of home heating.

From now on, the bureau will release multiyear estimates for mid-size areas every year, enabling local governments to make more-informed decisions about where to build roads, schools and community service centers, as well as helping them get their fair share of government funds based on economic need.

Yesterday's release "represents an important milestone for data users everywhere," said Census Bureau Director Steve H. Murdock. "Communities are no longer limited to a once-a-decade look at their population's characteristics. . . . [This] will allow small towns and communities to track how they are changing on an ongoing basis."

The figures -- available at http://www.factfinder.census.gov -- offer intriguing specifics about nearly 70 suburban Washington localities.

For instance, since the early 1990s, immigrants have been spreading far beyond gateway states and metropolitan centers to a broad swath of suburban counties across the country. This was reflected in the figures on mid-size communities, with foreign-born populations growing as fast in localities with fewer than 30,000 people as in more populous places, according to William H. Frey, a Brookings Institution demographer who analyzed the data.

Locally, immigration had its biggest impact in the Lanham-Seabrook area of Prince George's County. The foreign-born share of the population there jumped from 17 percent in 2000 to 35 percent by mid-decade.

However, the foreign-born population of the Linton Hall area of Prince William grew at the fastest rate in the area. A fivefold increase lifted the share of immigrants in the population from 6 percent to 17 percent between 2000 and the 2005-2007 period covered in yesterday's release.

The region's wealth is also reflected in the new data. Fairfax and Montgomery counties, regularly ranked among the nation's wealthiest counties, have three of only nine mid-size localities nationwide with median family incomes that exceeded $150,000 (in 2007 dollars). The figure was $181,773 in McLean, $177,506 in Potomac and $168,385 in Bethesda.

Database editor Dan Keating contributed to this report.