Statistics Canada published its annual update on university tuition this week, just as hundreds of thousands of Canadian students went back to class. University is where I have my day job so I’ve been scrolling through the CANSIM tables that backed up the update.

One thing I found interesting was how tuition varies by field of study. For instance, on average in Canada an executive MBA costs $51,891 a year. My experience of such programs is that they offer students lots of perks. For 50 grand a year, they had better! And that’s only the nationwide average price, which implies some programs charge more. I do believe most university classes add value. But do executive MBAs really add that much value?

By contrast, a regular MBA is a relative steal, at just $29,293 a year. We economists honour market processes. If people keep paying that to sit in class, they must feel they’re getting at least that much value.

StatCan’s series doesn’t provide tuition data for medical degrees but dentistry costs $12,652 on average and nursing $7,709. Law school is a paltry $5,874.

The best deal of all, however, is veterinary medicine, which costs $3,790 a year on average across the country. Less than $4,000 for a graduate degree.

One reason tuition may—and should—differ across fields is cost. If one program costs more than another, we want tuition to reflect that. If executives going back to school to get MBAs want perks, fine, but they should pay for them. If teaching would-be dentists is equipment- or labour- or insurance-intensive, as it probably is, the beneficiaries of such education should be forced to take that into account. Otherwise, we get lots of people consuming an expensive education that in the end may not pay well enough to be worth it.

So what is it about veterinary medicine that causes tuition to be so low? (I’d say “that causes it to be so reasonable” except that it being so low is not at all reasonable.) Is instruction inexpensive? That seems unlikely. You’d think teaching animal medicine is pretty much like teaching human medicine, except that the patients kick back rather than talk back.

Or is the explanation that our ministries of education, presumably encouraged by our farm lobbies—those mischievous dairy farmers again?—believe they have a mandate not to charge future veterinarians anything like the full costs of their education, thereby indirectly subsidizing agriculture? Because healthy animals are good for the economy?

But knowledgeable executives and well-educated lawyers and maybe even competent economists are good for the economy, too—and are often well-compensated by their employers for it. If people trained in a discipline do produce “external” benefits, we should reflect that in what they’re paid, not by reducing their training costs. Then they can compare the true costs of their education with the true benefits it helps them create for society, including both what employers pay them and also any extra compensation they receive for the social good they do on top of that. Taking into account the full costs and full benefits of their education, they can thus make a completely-informed decision about whether it will pay off. Which is what we want them to do.