The critics of the policy are operating under a "false assumption," Silverman said. But he said he has "no idea" how many new jobs would be filled by people already living in the county.
Census data suggest that the number of "imported" workers will be substantial. Between 1990 and 2000, the share of people working in Montgomery and living somewhere else grew 30 percent faster than the number of jobs.
Residents Madeline Hanington, left, with her dog Bilbo, and Alana Taylor stroll through still-developing Clarksburg.
(Photos Ricky Carioti -- The Washington Post)
_____Growth and Development_____
Md. Panel Backs Study Of Rte. 32 Widening (The Washington Post, Jul 22, 2004)
Loudoun Approves Ex-Chairman's Farm for Development (The Washington Post, Jul 7, 2004)
Southern Pr. George's Debates Development (The Washington Post, Jun 13, 2004)
Loudoun Approves More Utility Lines (The Washington Post, Apr 21, 2004)
Prince William Board Approves Restrictions on Big-Box Stores (The Washington Post, Apr 21, 2004)
As of 2000, about 154,000 workers were commuting to Montgomery, up from 140,000 in 1990.
"No matter how you dress it up, housing-jobs imbalance generally exacerbates sprawl," said Marya Morris, senior researcher at the American Planning Association.
It isn't just Montgomery, either.
The largest single housing-jobs gap in the region exists in Fairfax County, which spends $7 million a year to bring in jobs. It's part of the county's objective of drawing 25 percent of its real estate taxes from commercial properties instead of homes.
During the '90s, the number of jobs in Fairfax County rose from 404,000 to 533,000, according to county figures, for a rise of 129,000, while the home supply rose by 51,000.
Assuming the county average of 1.5 workers per home, this leaves a housing shortfall of 35,000 homes.
"We've been phenomenally successful at attracting jobs to this county," said Fairfax Board of Supervisors Chairman Gerald E. Connolly (D). "That creates a tax base to finance the kinds of services we want to have."
"It's a vicious cycle," said John McClain, a senior fellow at the Center for Regional Analysis at George Mason University. "Every county, it seems, is trying to load up on jobs but not houses."
'Make Their Neighbors Pay'
Even aside from the effects on sprawl and housing prices, critics blame such policies in Fairfax and Montgomery for, in effect, shifting the burdens of providing housing to neighboring jurisdictions. Some planners call this a "beggar thy neighbor" approach. Its use by the region's most affluent counties strikes some as particularly galling.
"What it comes down to is class warfare," said Michael Replogle, a former Montgomery County planner who works for Environmental Defense. "It's an effort to keep low tax rates in one of the most affluent jurisdictions and make their neighbors pay."
For people who work in Montgomery, affordable housing often means a commute north on Interstate 270. At Human Genome Sciences in Rockville, for example, more than 100 of the company's 1,100 workers live in Frederick County, six go even farther to Hagerstown and three live in Pennsylvania, according to company figures.
In the Clarksburg area, one of four workers lives outside the county, according to local employment figures. When the offices slated to be built in Clarksburg are completed, the proportion living in those northern locations is likely to be higher because the gap between jobs and housing in Montgomery will have grown.