The high cost of college education may be driving young people into engineering, computer technology and other well-paid fields, when in fact they would rather be doing something else. The evidence of a link between tuition costs and choice of major is still sketchy, but the preliminary numbers, from a study by the Carnegie Foundation for the Advancement of Teaching, are startling.

About a fifth of the 5,000 college students surveyed said they planned careers in business; but fewer than half of the business majors listed business as their area of principal interest. Only a third of those who chose careers in engineering or computer science listed those fields as their main interest. These candidates for career frustration are following their pocketbooks, because following their hearts turns out to be bad economics.

The foundation suggests that "the pressure to make money may, in fact, be shaping the enrollment pattern of the students." It points out that while the public debate has focused on government grants and loans, most college students rely most heavily on private resources -- savings, family contributions and private loans -- to pay for their schooling. With the annual cost of education running from around $5,000 a year in public colleges to nearly $10,000 in private ones, and 71 percent of American families earning less than $35,000 a year 1983 figures , students face such substantial debt that they may be guided more by how much they can earn than by what they would like to do.

The survey appears in Change, the Magazine of Higher Learning, the entire May-June issue of which is devoted to the soaring cost of college education. Its conclusions are more inference than hard fact. Still it seems reasonable to suppose that the high rate of borrowing for college may be one of the reasons young people are flocking to the more lucrative careers, even when their personal preferences are elsewhere.

There are exceptions. Among music majors (just two percent of those surveyed) 83 percent list their major as their primary field of interest, as do 60 percent of those planning careers in the ministry, 53 percent of prospective farmers and 52 percent of would-be lawyers.

And there are seeming contradictions. If majoring in fields other than their primary interest is the result of cold economic considerations, why is it that only 10 percent of prospective secondary school teachers (but 35 percent of elementary education majors) list teaching as their primary field of interest?

Still, the basic conclusion of the Carnegie Foundation study seems correct: that we need to rethink the way we make loans and grants, perhaps delaying loans (and student indebtedness) until a student is far enough along to have a very good chance of graduating, and tailoring the mix of grants and loans to the student's earning prospects. As it is, we "package" student aid as though one major is the same as another.