The current U.S. education system is failing to prepare millions of young adults for successful careers by providing a one-size-fits-all approach, and it should take a cue from its European counterparts by offering greater emphasis on occupational instruction, a Harvard University study published Wednesday concludes.

The two-year study by the Pathways to Prosperity Project at the Harvard University Graduate School of Education notes that while much emphasis is placed in high school on going on to a four-year college, only 30 percent of young adults in the United States successfully complete a bachelor's degree.

While the number of jobs that require no post-secondary education have declined, the researchers note that only one-third of the jobs created in the coming years are expected to need a bachelor's degree or higher. Roughly the same amount will need just an associate's degree or an occupational credential.

What I fear is the continuing problem of too many kids dropping by the wayside and the other problem of kids going into debt, and going into college but not completing with a degree or certificate," said Robert Schwartz, who heads the project and is academic dean of the Harvard Graduate School of Education. "Almost everybody can cite some kid who marched off to college because it was the only socially legitimate thing to do but had no real interest.

The report highlights an issue that has been percolating among education circles: That school reform should include more emphasis on career-driven alternatives to a four-year education.

The study recommends a "comprehensive pathways network" that would include three elements: embracing multiple approaches to help youth make the transition to adulthood, involving the nation's employers in things like work-based learning, and creating a new social compact with young people.

Many of the ideas aren't new, and leaders, including President Barack Obama, have advocated for an increased role for community colleges so the country can once again lead the world in the proportion of college graduates. U.S. Education Secretary Arne Duncan will deliver opening remarks at the report's release in Washington.

But the idea of providing more alternatives, rather than emphasizing a four-year college education for all, hasn't been without controversy. Critics fear students who opt early for a vocational approach might limit their options later on, or that disadvantaged students at failing schools would be pushed into technical careers and away from the highly selective colleges where their numbers are already very slim.

You've got to work on both fronts at once," Schwartz said, arguing for intensifying efforts to get more low-income and minority students into selective institutions while strengthening the capacity of two-year colleges.

The study recommends that all major occupations be clearly outlined at the start of high school. Students would see directly how their course choices prepare them careers that interest them — but still be able to change their minds. Students should also be given more opportunities for work-based learning, such as job shadowing and internships.

Students, the researchers recommend, should get career counseling and work-related opportunities early on — no later than middle school. In high school, students would have access to educational programs designed with the help of industry leaders, and they'd be able to participate in paid internships.

The report notes that many European countries already have such an approach, and that their youth tend to have a smoother transition into adulthood. And not all separate children into different paths at an early age. Finland and Denmark, for example, provide all students with a comprehensive education through grades 9 or 10. Then they are allowed to decide what type of secondary education they'd like to pursue.

Barney Bishop, president and CEO of Advanced Industries of Florida, said he would advocate for an approach that provides more alternatives and greater inclusion of the business community.

The problem for the business community is where you have kids who don't have the rudimentary skills, and you have to take the time and effort to train them, get them some of the rudimentary skills, plus the special skills," he said.

Sandy Baum, an independent higher education policy analyst, said she think there needs to be more counseling in advising students about how to make the right choices.

I don't think the problem is too many people going to four-year colleges," she said. "The problem is too many people making inappropriate choices.

What we'd like is a system where people of all backgrounds could choose to be plumbers or to be philosophers," Baum added. "Those options are not open. But we certainly need plumbers so it's wrong to think we should be nervous about directing people in that route.