The last four years have witnessed an astonishing implosion of a previously unquestioned investment strategy. No, I don't mean "Buy a house"; I'm talking about "Go to law school." Law school was never quite as safe as people thought, but except for John Grisham, almost no one wrote about the desperate people who end up at the bottom of the legal food chain. Then, during the Great Recession, when you'd expect graduate school applications to be spiking, something unthinkable happened: they started to fall.

The response was entirely rational, as Paul Campos laid out in my interview with him about his book, Don't Go to Law School.

Now that we have real data, I estimate that the median salary of ABA law school graduates a year after graduation is around $45,000, and this may be if anything optimistic. And median educational debt is around $150,000 and climbing rapidly.

So what used to be (as you say) a risk averse choice for people who decided to give up on writing the great American novel has turned into an extremely risky and indeed often flat out reckless gamble, wihch still retains the appearance of a sensible and prudent thing to do in the eyes of clueless baby boomer parents etc.

Now the Wall Street Journal suggests that the same transition may be happening to people with MBAs:

Formerly, the traditional M.B.A. was mainly the product of a full-time, two-year program. But beginning in the early 1990s, many schools created part-time and executive M.B.A. programs, with lower-ranked schools often following in the footsteps of academic leaders. Online degrees also gained in popularity.

As a result, the number of M.B.A. degrees granted has grown faster than the population, says Brooks Holtom, a management professor at Georgetown University's McDonough School of Business.

"An M.B.A. is a club that is now not exclusive," he says. "You should not assume that this less exclusive club is going to confer the same benefits."

The article is crammed with sad anecdotes. But when you dig into it, I'm not sure how much of this is news. Almost all the discussion is of third-tier regional schools. It was a commonplace when I was applying to business school, way back in 1999, that there wasn't much point in getting an MBA unless you could get into a top-tier school; the degree simply wouldn't repay the investment of time and money. That clearly hasn't changed, but I'm not sure there's much evidence that it's gotten worse, either—except in the sense that more people are getting degrees of questionable value.

For graduates with minimal experience—three years or less—median pay was $53,900 in 2012, down 4.6% from 2007-08, according to an analysis conducted for The Wall Street Journal by PayScale.com. Pay fell at 62% of the 186 schools examined.

It's not unusual for starting pay to fall during a weak economy. What this really highlights is what business schools rarely tell you when they're selling you on their school: students with weak experience and lower-tier degrees aren't getting the six figure salaries that people associate with an MBA. Students with more experience do better--but need the credential less. The high-paying employers that people hope to wow with their degrees don't recruit very far down the prestige ladder, as one person they interview acknowledges:

Casting a wider net remains a challenge. "It's always difficult to get those upper-tier companies to come and recruit," says T. Vernon Foster, who oversees career services. "Once they do, they are always impressed."

It strikes me as a real problem that more people are paying a lot for degrees that don't necessarily boost their earning potential. It's a symptom of two worrying economic trends: the relentless push for ever more educational credentials, and the stagnant labor market.

Lackluster economic growth means that there are fewer opportunities for young workers to move up, or try new industries if they don't like where they've found themselves. Or find a job, if their last one didn't work out. The natural instinct is to seek some sort of swing mechanism that can get them out of a tight spot in the labor market.

For decades, that mechanism has been a degree: first a BA, and then, as those became more common, a master's. As long as master's degrees and professional degrees were rare, it was a decent strategy. Unfortunately, it's the sort of strategy that only works when few people are doing it; if everyone gets an MBA, then your swing becomes more like a very expensive bench. Graduates of elite schools still do all right, because there are a limited number of slots. The rest pay a lot of money for very little opportunity.

The last two decades have witnessed an aggressive expansion of graduate programs, particularly in areas like business and law. Schools love them because they're cash cows: low cost, high price. But they don't provide good value to their graduates. When young people ask me whether they should get an MBA, I give them the same advice that I got in the late 1990s: unless you can get into a top 10* (or have a very specific job that you know you can get by attending a regional program), then don't. You're too likely to end up with massive debt and no very good prospects for paying it.

Hell, I did go to a top school, and nonetheless, through a series of unfortunate events, faced a long spell of unemployment that ended when I accepted a job that left me personally rewarded, but financially somewhat desperate. And there are many, many more people in that situation whose degrees come from third-tier schools with little in the way of name recognition or alumni networks. That's why I always urge people to think very, very hard before they decide to go to professional school. It was no fun at all paying high five-figure debt on a low five-figure salary. I don't recommend the experience to anyone else.

Of course, I don't regret my career path--I have the closest thing there is to a dream job. And getting an MBA was a big part of that. But it involved an incredible, improbable string of lucky events that I, for one, certainly wouldn't bet on replicating.

If you're stuck in a career dead end and you're feeling desperate, but you don't have the GMATs or grades to get into a top program, then at the very least you should read a couple of books like What Color is My Parachute, 48 Days to the Work You Love, or Quitter, and try some of the strategies you read about, before you pay tens of thousands of dollars for the rosy promises of a local MBA program.

This is not popular advice, and I can't say that everyone takes it. We're programmed to think of school as the solution to our career problems, and it seems like such an easy solution: you show up and do exactly what your professors tell you in the company of a lot of people your own age, and voila! A valuable new credential. There's the cost, of course, but the government makes that easy too. It's certainly a lot more relaxing than the strategies that business books suggest, which involve pestering people who work in fields or places that you'd like to be, and opening yourself up for an incredible amount of rejection.

In fact, it is an easy solution: too easy. That's why it isn't much of a solution to the problem of distinguishing yourself in the labor market and gaining access to a limited number of highly sought-after jobs. And teaching yourself to go after what you want, and accept the inevitable rejection that comes with that, will add more to your earning power than anything they you could possibly learn in class.

Too many law school and business school graduates have learned all this, to their dismay, after they've racked up five- or six-figure debts to pay for their credential. It's good news that law applicants are finally catching on. Hopefully, MBA applicants will as well.

*Weirdly, the Top 10 is/was composed of about fifteen schools. This is why so many MBAs need to attend math boot camp before classes start.