Imagine that America had no system of post-secondary education, and you were a member of a task force assigned to create one from scratch. One of your colleagues submits this proposal:

First, we will set up a single goal to represent educational success, which will take four years to achieve no matter what is being taught. We will attach an economic reward to it that seldom has anything to do with what has been learned. We will urge large numbers of people who do not possess adequate ability to try to achieve the goal, wait until they have spent a lot of time and money, and then deny it to them. We will stigmatize everyone who doesn't meet the goal. We will call the goal a "BA."

You would conclude that your colleague was cruel, not to say insane. But that's the system we have in place.

Finding a better way should be easy. The BA acquired its current inflated status by accident. Advanced skills for people with brains really did get more valuable over the course of the 20th century, but the acquisition of those skills got conflated with the existing system of colleges, which had evolved the BA for completely different purposes.

Outside a handful of majors -- engineering and some of the sciences -- a bachelor's degree tells an employer nothing except that the applicant has a certain amount of intellectual ability and perseverance. Even a degree in a vocational major like business administration can mean anything from a solid base of knowledge to four years of barely remembered gut courses.

The solution is not better degrees, but no degrees. Young people entering the job market should have a known, trusted measure of their qualifications they can carry into job interviews. That measure should express what they know, not where they learned it or how long it took them. They need a certification, not a degree.

The model is the CPA exam that qualifies certified public accountants. The same test is used nationwide. It is thorough -- four sections, timed, totaling 14 hours. A passing score indicates authentic competence (the pass rate is below 50%). Actual scores are reported in addition to pass/fail, so that employers can assess where the applicant falls in the distribution of accounting competence. You may have learned accounting at an anonymous online university, but your CPA score gives you a way to show employers you're a stronger applicant than someone from an Ivy League school.

The merits of a CPA-like certification exam apply to any college major for which the BA is now used as a job qualification. To name just some of them: criminal justice, social work, public administration and the many separate majors under the headings of business, computer science and education. Such majors accounted for almost two-thirds of the bachelor's degrees conferred in 2005. For that matter, certification tests can be used for purely academic disciplines. Why not present graduate schools with certifications in microbiology or economics -- and who cares if the applicants passed the exam after studying in the local public library?

Certification tests need not undermine the incentives to get a traditional liberal-arts education. If professional and graduate schools want students who have acquired one, all they need do is require certification scores in the appropriate disciplines. Students facing such requirements are likely to get a much better liberal education than even our most elite schools require now.

Certification tests will not get rid of the problems associated with differences in intellectual ability: People with high intellectual ability will still have an edge. Graduates of prestigious colleges will still, on average, have higher certification scores than people who have taken online courses -- just because prestigious colleges attract intellectually talented applicants.

But that's irrelevant to the larger issue. Under a certification system, four years is not required, residence is not required, expensive tuitions are not required, and a degree is not required. Equal educational opportunity means, among other things, creating a society in which it's what you know that makes the difference. Substituting certifications for degrees would be a big step in that direction.

The incentives are right. Certification tests would provide all employers with valuable, trustworthy information about job applicants. They would benefit young people who cannot or do not want to attend a traditional four-year college. They would be welcomed by the growing post-secondary online educational industry, which cannot offer the halo effect of a BA from a traditional college, but can realistically promise their students good training for a certification test -- as good as they are likely to get at a traditional college, for a lot less money and in a lot less time.

Certification tests would disadvantage just one set of people: Students who have gotten into well-known traditional schools, but who are coasting through their years in college and would score poorly on a certification test. Disadvantaging them is an outcome devoutly to be wished.

No technical barriers stand in the way of evolving toward a system where certification tests would replace the BA. Hundreds of certification tests already exist, for everything from building code inspectors to advanced medical specialties. The problem is a shortage of tests that are nationally accepted, like the CPA exam.