THE U.S. SYSTEM of higher education is widely considered the world’s best. A college education confers substantial benefits, both intangible and monetary — about $20,000 per year in extra earnings over the course of a lifetime. Yet, according to a recent survey by the Pew Research Center, 57 percent of Americans think higher education is not a good value, even though they know how much it boosts earning power. Three-quarters say that college is too expensive for most people. And with the cost of many state universities skyrocketing — next fall, the University of California’s in-state tuition may be double what it was just six years ago — those perceptions are understandable.

Clearly, higher education officials must think harder about affordability — including not only more scholarship money but also lower costs and higher efficiency. One promising idea is the three-year degree, which would enable U.S. students to get their bachelor’s in the same period that students in other countries, notably England, get theirs, rather than in the four-year span that has gone more or less unquestioned since Harvard decreed it back in 1652. Students would have to spend (and borrow) less, and they would have an extra year of work to defray the costs of education.

There are many potential approaches to the three-year degree: Schools can make it easier for students to apply college credit earned in high school; they can fashion programs that pack nearly four years of credits into three years, making use of summer and online learning; they can consider a more focused and streamlined curriculum. What all such ideas assume is that universities and colleges could make more intensive use of resources that often lie idle for much of the year under the existing paradigm.

So it’s disappointing to learn, from reporting in The Post by Daniel De Vise, that three-year degree programs are still offered by only a relative handful of schools, most of them small, private institutions, and that student demand remains weak. In part, this reflects the fact that students are in no hurry to exit the halcyon campus life. But another problem is that some colleges offer three-year degrees without cutting tuition to three-quarters of a four-year degree.

Colleges and universities face powerful economic incentives to stick with the four-year model. Most won’t offer a three-year option unless and until those incentives change. That may be starting to happen: The recent budget proposal by Ohio Gov. John Kasich (R) requires the state’s public universities to prepare plans to offer three-year undergraduate degrees for 10 percent of their programs by 2012 and for 60 percent by 2014. It probably will take successful innovation by one or more large state systems to spur change nationwide. Perhaps federal aid to universities or the schools’ participation in the student loan program could be partly conditioned on offering a three-year degree option. Today’s students have the capability to acquire and distribute knowledge faster than any previous generation, thanks to technology. Higher education needs to catch up.