For many students, college is less about providing an education than a credential--a certificate testifying that they are smart enough to get into college, conformist enough to go, and compliant enough to stay there for four years.
When I was a senior, one of my professors asked wonderingly, "Why is it that you guys spend so much time trying to get as little as possible for your money?" The answer, Caplan says, is that they're mostly there for a credential, not learning. "Why does cheating work?" he points out. If you were really just in college to learn skills, it would be totally counterproductive. "If you don't learn the material, then you will have less human capital and the market will punish you--there's no reason for us to do it." But since they think the credential matters more than the education, they look for ways to get the credential as painlessly as possible.