It will come as no surprise that household incomes shot up in some parts of the Washington area in 2003 as the regional economy recovered from a slump. But in a big surprise, a new survey purports to show that people in one prosperous county brought home significantly less cash than the year before.

Showing big increases, according to the Census Bureau's American Community Survey, median household income in Prince William County rose to $82,926 last year from $70,334 in 2002. Howard County income also rose sharply, to $88,555 from $80,501.

But the county that by many measures has reported the strongest economic growth in the past year did worse in the Census Bureau survey. Fairfax County had an average household income of $80,753 last year, down from $85,310.

One possible explanation: Statistics show workers are shifting to government contractors, whose business is booming but who often pay less than the commercial technology companies that pulled back after the tech crash.

While the numbers for Fairfax are surprising, and there is a margin of error in the sampling that could help explain the decrease, the survey is taken seriously and is closely watched by economists and local governments.

Household income in the District and Montgomery also dropped slightly. It rose a bit in Prince George's and Anne Arundel counties.

The numbers, released in late August each year, are based on a monthly survey of a sample of residents in each U.S. county with more than 250,000 people.

The Commerce Department also tracks personal income in every county. Commerce's numbers are based on corporate filings with state employment agencies and thus generally are more reliable indicators. But the 2003 Commerce Department information won't be available until spring.

For now, it looks like the recovery has had a more mixed impact on residents' wallets than people thought.

-- Neil Irwin