A scarcity of workers of all kinds is an overriding fact of life for the suburban Washington economy, affecting all sorts of business decisions, executives and analysts agree.

To appreciate the shortage's steadily tightening grip, try looking at the employment numbers in the region in a different way.

The unemployment rate has been below 2 percent in Fairfax and Loudoun counties for more than a year, and in March it sank to an almost incredible 1 percent in Loudoun County. Montgomery, Howard and Arlington counties are also in the under-2 percent list now. That trend isn't news.

But put another way, for every unemployed person in Fairfax County in 1997, there were 43 Fairfax residents holding down jobs, based on annual averages.

This year, the figure has jumped to 68 county residents with jobs for every unemployed resident.

Looking at these comparisons, it's easy to recognize the high-growth, high-stress communities in the region.

The District had 12 working residents for each unemployed resident over the first three months of this year. The comparable ratios are 27 to 1 in Prince George's County, 50 to 1 in Montgomery, 65 to 1 in Arlington, 68 to 1 in Fairfax and 91 to 1 in Loudoun. That's right, 91 county residents employed for every one on the jobless rolls.

Despite all their hiring problems, the region's suburban employers have kept growing. Payroll employment in the Washington area through April is running 3.2 percent above last year's level, well above the national average and higher than at any time in the 1990s.

The job growth has been fed, of course, by the migration of new workers to the region.

The newcomers have ignited a housing boom. The property values on residential building permits in Northern Virginia increased 19 percent last year over 1997. It hardly stopped there. So far this year, building permit values are 35 percent above the first quarter of 1998, said Roy L. Pearson, an economist at the College of William and Mary in Williamsburg.

But before long, the shortage of workers will begin slowing the economy down, predicts Pearson, whose estimates are often more cautious than official Virginia forecasts.

Employers are facing higher and higher costs of finding workers as they expand their search far beyond the region, he said. And the wage costs of the workers they do find are going up steadily.

That combination means that the kind of job growth registered in Northern Virginia last year is probably unsustainable, Pearson contends.