It used to be that the smart kids went to graduate school. But today, the workplace is different, and it might be that only the desperate kids go to graduate school. Today there are new rules, and new standards for success. And for most people, graduate school is the path to nowhere. Here are seven reasons why:

1. Graduate school is an extreme investment for a fluid workplace. If you are graduating from college today, you will change careers about five times over the course of your life. So going to graduate school for four years—investing maybe $80,000—is probably over-investing in one of those careers. If you stayed in one career for your whole life, the idea is more reasonable. But we don't do that anymore, so graduate school needs to change before it is reasonable again.

2. Graduate school is no longer a ticket to play. It used to be that you couldn't go into business without an MBA. But recently, the only reason you need an MBA is to climb a corporate ladder. And, as Paul Graham says, "corporate ladders are obsolete." That's because if you try to climb one, you are likely to lose your footing due to downsizing, layoffs, de-equitization, or lack of respect for your personal life. So imagine where you want to go, and notice all the people who got there already without having an MBA. Because you can do that, too, in a wide range of fields, including finance.

3. Graduate school requires you to know what will make you happy before you try it. But we are notoriously bad at knowing what will make us happy. The positive psychology movement has shown us that our brains are actually fine-tuned to trick us into thinking we know about our own happiness. And then we make mistakes. So the best route to happiness is one of trial and error. Otherwise, you could over-commit to a terrible path. For example, today most lawyers do not like being lawyers: more than 55% of members of the American Bar Association say they would not recommend getting a law degree today.

4. Graduate degrees shut doors rather than open them. You better be really certain you know what you're going to do with that degree because you're going to need to earn a lot of money to pay it back. Law school opens doors only to careers that pay enough to repay your loans. Likewise, your loan payments from an MBA program mean that you cannot have a scrappy start-up without starving. Medical school opens doors to careers with such bad work-life balance that the most popular specialty right now is ophthalmology because it has good hours.

5. If you don't actually use your graduate degree, you look unemployable. Let's say you spend years in graduate school (and maybe boatloads of money), but then you don't work in that field. Instead, you start applying for jobs that are, at best, only tangentially related. What it looks like is that you are asking people to give you a job even though you didn't really want to be doing that job. You wanted another job but you couldn't get it. No employer likes to hire from the reject pile, and no employer wants to be second choice.

6. Graduate school is an extension of childhood. Thomas Benton, columnist at the Chronicle of Higher Education, says that some students are addicted to the immediate feedback and constant praise teachers give, but the work world doesn't provide that. Also, kids know how to do what teachers assign. But they have little idea of how to create their own assignments—which is what adult life is, really. So Benton says students go back to school more for comfort than because they have a clear idea of what they want to do with their life.

7. Early adult life is best if you are lost. It used to be that you graduated from college and got on a path. The smart kids got themselves on a safe path fast. Today there are no more safe paths, there is only emerging adulthood, where you have to figure out who you are and where you fit, and the quarter-life crisis, which is a premature midlife crisis that comes when people try to skip over the being lost part of early adult life. Being lost is a great path for today's graduates. And for most people, graduate school undermines that process with very little reward at the end.

Dan Ariely, economist at MIT, found that when people have a complicated choice to make—and there is a default choice—they pick the default nearly every time. So if your parents or friends went to graduate school, you are likely to do the same, not because it's good for you personally, but because choosing the alternatives seem more difficult. But making exactly that kind of difficult choice is what your early adult life is all about. So don't skip it.