Fundamentally, [essay plagiarism] is a problem of misplaced economic incentives. As long as the academic credential is worth more to a student than the knowledge gained in getting that credential, there will be an incentive to cheat.
There’s an implicit, vague critique of higher education here to which I am sympathetic. But, unfortunately, many students are too early in their careers to know how to value a knowledge they will only be able to use later on; in many cases, only many years later.
Certainly you can test for knowledge via examinations (MCATS, the Bar) which test recall and, through simulations, applied knowledge. But what would such an entrance or licensing exam look like for the humanities? Would you hire ethicists to fill out the testing board? How would you structure a test for joining civil society?
Previously on essay mills, outsourcing.