The number of young men who earn between $30,000 and $100,000 has fallen significantly during the last 40 years, even though they are better educated and working full time at the same rate.

The loss of blue-collar jobs, many now performed by machines or by workers overseas, is forcing more men into low-wage service jobs and, in some cases, is causing them to drop out of the work force.

Many young men have fallen to the bottom of the income scale, according to an article in the Boston Globe that was based on a new analysis by the U.S. Census Bureau.

The jobs that are growing the fastest, on the other hand, are concentrated in female-dominated professions such as health care.

Men also have fallen behind academically and, combined with the fact that manufacturing and other lower-skilled jobs have disappeared, this has created a “riptide that is carrying so many young men out to sea economically,” said Neil Sullivan, executive director of the Boston Private Industry Council, a workforce development non-profit.

The increasingly fractured economy is affecting workers of all ages. Wages have stagnated as the cost of living and student debt have skyrocketed, and college graduates are taking lower-level jobs than in the past. But men are being hit particularly hard, as many are forced to take contract or part-time work.

Many young men — defined by the Census Bureau as ages 25 to 34 — are starting out their working lives at a distinct disadvantage, compared with previous generations. And as more of them live at home and delay marriage, young adulthood has started looking much different than it used to.

“This has an effect on their entire lives,” said Elise Gould, a senior economist at the left-leaning Economic Policy Institute, who recently co-authored a report on new high school and college graduates. “Those first jobs are going to set you up for your lifetime of earnings.”