Chester County's jobless rate rose to 3.9 percent in November from 3.5 percent in October.
Seasonal economic factors routinely taken into account by the Pennsylvania Department of Labor and Industry were mainly to blame for the uptick, according to Douglas Schmidt, who manages the Chester County CareerLink office in Coatesville.
"People who have called off their job search often start looking again in November," Schmidt explained. "Also, many college students graduate in December. Most begin their job-hunt search a month before they're set to graduate."
As Schmidt pointed out, the jobless rate in Chester County and elsewhere often bumps up in November and December, then settles down again after New Year's.
Assistant Economist Ryan Sweet with Moody's Economy.com cautioned against reading too much into a one-month increase in the local jobless rate.
"These numbers are volatile and they swing up and down," he said. "The more important comparison is year-over-year."
Last year in November, Chester County's jobless rate stood at 3.7 percent. In November 2004, 9,300 county residents were out of work; by last month, that number had risen by 500 to 9,800.
The boost was also at least partly attributable to the layoffs and acquisitions that occurred in Chester County during the fall.
In October, for instance, Saint-Gobain Performance Plastics announced that it would close its East Whiteland plant, throwing 43 employees out of work by March. Those layoffs have already begun.
And, when GameStop Inc. in October acquired arch-rival Electronics Boutique, headquartered in West Goshen, it also announced that it would close EB's home base here, as well as its cavernous distribution facility in Sadsbury.
That move, most of which takes place in the first half of 2006, means that at least 734 people will be out of a job come July.
Those already laid off have applied for or are in the process of applying for unemployment benefits. Typically, GameStop announces headquarters layoffs once a month, to take effect 60 days later.
Unemployment also increased in the larger 12-county Philadelphia-Camden-Wilmington metropolitan statistical area, from 4.4 percent in October to 5 percent in November.
And, in Pennsylvania, the jobless rate also rose month over month, from 4.6 percent in October to 5.1 percent in November.
The national unemployment rate stood at 5 percent in November, unchanged from the previous month.
All statistics are seasonally adjusted.
Despite the upswing, Chester County still had the third-lowest unemployment rate among Pennsylvania's 67 counties in November. First was Franklin, at 3.7 percent, followed by Adams at 3.8 percent. Chester County tied for third with Cumberland and Lebanon.