Such language may sound out of step with a jobless rate that, despite its recent rise, remains at 6.7 percent; the rate exceeded 10 percent in the early 1980s. But over the last few decades, the jobless rate has become a significantly less useful measure of the country’s economic health.

That is because far more people than in the past fall into the gray area of the labor market  not having a job and not looking for one, but interested in working. This group includes many former factory workers who have been unable to find new work that pays nearly as well and are unwilling to accept a job that pays much less. Some get by with help from disability payments, while others rely on their spouses’ paychecks.

For much of the last year, the ranks of these labor force dropouts were not changing rapidly, said Thomas Nardone, a Labor Department economist who oversees the collection of the unemployment data. People who had lost their jobs generally began looking for new work. But that changed in November.

Much as many stock market investors threw in the towel in early October, and consumers quickly followed suit by cutting their spending, job seekers seemed to turn darkly pessimistic about the American economy in November. Unless the numbers turn out to have been a one-month blip, large numbers of people seem to have decided that a job search is, for now, futile.

“It’s not only that there’s nothing out there,” said Lorena Garcia, an organizer in Denver for 9to5, National Association of Working Women, a group that helps low-wage women and women who are looking for work. “But it also costs money to job hunt.”

Just how bad is the labor market? Coming up with a measure that is comparable across decades is not easy.

The unemployment rate has been made less meaningful by the long-term rise in dropouts from the labor force. The simple percentage of people without jobs  including retirees, stay-at-home parents and discouraged would-be job seekers  can also be misleading, though. It has dropped in recent decades mainly because of the influx of women into the work force, not because the job market is fundamentally healthier than it used to be.