THE unemployment rate is low. The jobless rate is high.

Those two seemingly contradictory statements are especially true for American men in what should be the prime of their working lives. Those facts may help to explain the stark pessimism of Americans about the economy, and shed some light on the rise of illegal immigration as a political issue.

Men in the prime of their working lives are now less likely to have jobs than they were during all but one recession of the last 60 years. Most of them do not qualify as unemployed, but they are nonetheless without jobs.

The unemployment rate paints a less gloomy picture. Among men ages 25 to 54  a range that starts after most people finish their education and ends well before most people retire  the unemployment rate is 4.1 percent. That is not especially low, but it is well below the peak rate in all but one post-World War II recession.

Only people without jobs who are actively looking for work qualify as unemployed in the computation of that rate. It does not count people who are not looking for work, whether or not they would like to have a job.