THE rise in unemployment that has occurred in the current recession has been hardest on young workers, while having a smaller effect on older workers than previous downturns. Women have been more likely than men to hold on to their jobs.

The overall unemployment rate, which reached 10.2 percent on a seasonally adjusted basis last month, remains below the post-World War II peak of 10.8 percent, reached in late 1982. But the proportion of workers who have been out of work for a long time is higher now than it has ever been since the Great Depression.

The persistence of joblessness for so many people  5.6 million Americans have now been out of work for more than half a year even though they have continued to seek employment  may provide the greatest challenge for the Obama administration if it decides to seek a new economic stimulus program.

The short-term unemployment rate  the proportion of the work force that has been jobless for less than 15 weeks  has begun to decline, however, and stood at 4.5 percent in October after peaking at 4.9 percent in May.