Entering the job market? Your education matters more than ever.

The Great Recession has accelerated what was already a long-term trend: A job market that holds much more promise for the educated and trained than for people with fewer skills.

Consider just one big-picture comparison: The unemployment rate in March was 4.2 percent for people with college degrees, versus 12.6 percent for people who lack a high school diploma, with the national average right in between those two figures at 8.2 percent.

And beneath that broad trend, some credentials are much more valuable than others. In many fields of study, recent college graduates have jobless rates that are close to the national average or higher, simply because there are so many experienced workers who are also looking for jobs. But in health and education fields, where demand is high, the jobless rate is only about 5.5 percent for recent grads, according to Georgetown University's Center on Education and the Workforce.

"It's really imperative that people pay attention to where the demand is going to be," says Nicole Smith, a senior economist at the Center on Education and the Workforce. "It's not just about which occupations are going to grow," she says, but also about how skill levels influence earnings.

Even before 2008, the rise of new technologies was boosting demand for skilled workers, while global competition was eroding the number of blue-collar jobs fields where a high-school diploma could be a ticket to middle-class wages. The recession amplified the process, imposing some of the sharpest job losses on less-skilled factory and construction workers.

Of course, the recession's toll was broader than that. Plenty of college grads are unemployed or underemployed. But the hardest to fill jobs these days often are ones where pay is relatively high, not low.

In computer science and math, for example, every online "help-wanted" listing in March was matched by less than 1 unemployed person in those fields, according to the Conference Board, a business research group in New York. The average wage in those occupations is nearly $38 an hour.

Similarly, the supply of workers is relatively tight for engineers, scientists, and health-care practitioners, all fields with high average pay. By contrast, lower-paying fields including food service, personal care, factory production, and transportation all have a high ratio of jobless workers to job openings.

And Ms. Smith says the long-term outlook is clear: The jobs of the future will demand more know-how than the ones of the past.

The pattern has implications for workers of all types. For people who don't attend college, Smith recommends being licensed or certified for some trade, for example.

There is some good news in a new Labor Department forecast, which predicts job gains in virtually all broad occupational categories. The department's "Employment Projections" says job openings in the coming decade will include many for less-skilled workers: 2 million in retail sales, 5 million in cooking and food service, and growth in numerous smaller occupations as well – bicycle repairers, the nation will need about 6,000 more of you.

The labor forecast covers some 750 occupations, from ones poised to shrink in size (Postal Service workers, telephone operators) to ones with faster than average growth. By 2020, jobs are expected to open up for 49,000 pest control workers, 232,000 preschool teachers, 59,000 architects, 93,000 musicians or composers, 40,000 translators, 315,000 social workers, and 25,000 masons or tile setters.

But labor experts still see the problem of a "skills mismatch" as a big one.

"Many employers are saying they can't find workers with the right skill sets," says Julian Alssid, executive director of a consulting group called the Workforce Strategy Center, in Barrington, Rhode Island.

It's visible in specific fields and it's a more general issue. The workforce researchers at Georgetown argue that for several decades, the education system hasn't been boosting work-force skills as fast as the economy could use. So the pay premium for high-skill workers has been growing, contributing to a widening of income inequality.

How bad is the problem? That's a matter of debate. Ohio University economist Richard Vedder argues against too much emphasis on college enrollment. "The number of new college graduates far exceeds the growth in the number of technical, managerial, and professional jobs where graduates traditionally have gravitated," he writes in a recent Bloomberg Businessweek column.

A Businessweek analysis, conducted by the Seattle firm PayScale, finds that college generally yields a positive "return on investment" for those who go. But the return varies a lot, from $1.7 million (spread over 30 years) for a graduate of CalTech to an average of $333,000 for 853 colleges analyzed.

Georgetown's Center on Education and the Workforce is bullish on the demand for education, whether that means a college degree or another credential. Although the Labor Department research emphasizes the minimum skills required to enter a line of work, Smith says it's more important to look at the education levels that are typical of workers in that field. By that measure, the share of US jobs demanding more than a high school education has roughly doubled in the past three decades, to about 60 percent of all jobs.

Meanwhile, other nations are also "upskilling" in a bid to capture more of the high-wage jobs.

"We're in a globally competitive marketplace," Mr. Alssid says. "If we can't produce the workers needed today, we’re going to lose those jobs."