Whatever you earn at age 40 is likely to be the top of your earning potential. This is one of a gazillion things I've learned from talking with Al Lee, the director of quantitative analysis at PayScale.

Al’s data, which is based on the careers of college graduates, is basically that the salary curve for most people in their 20s is very steep. Then it starts to flatten in the 30s, and then you get into the land of the 3% raise. In real dollars, those 3% raises are not actually raises, they are just keeping up with inflation.

The information is grim. But here are some things you can do with it:

1. Go where the men are. To be precise, pay tops out at age 38 for women ($61K) and age 45 for men ($95K). But the difference, according to PayScale data, is not due to unequal pay for equal work. Rather, the difference is that women choose lower paying careers, and women are more likely to take time out of the workforce for kids. So the first thing you can do to prevent your salary from flat-lining is choose a career that men dominate. But it's not just about industry—it is also about influence. Stick to line-management positions rather than support roles. For example, skip human resources and go to supply chain management.

2. Rewrite your resume. If you're at the beginning of your career, focus on accomplishments rather than responsibilities. This makes you look like you're in a higher pay bracket so you will get larger salary increases. If you've been in the workforce for a while, cut anything that is more than 15 years old, including the date of your college graduation. Al says that there is no premium paid for two decades of experience because jobs change so quickly that long-gone experience is not particularly relevant. And because age discrimination creates a sort of penalty for more than 15 years of experience. So just leave it off. (Good resume editing tips here, at Quint Careers.)

3. Be a lawyer. Have I ever given this advice before? I don't think so. Even the American Bar Association reports that law school is a ripoff. But I'm open to counter-arguments—Al says that the only profession where your pay increases after 20 years is in law. Because laws change very slowly, especially procedural law, and so much of being a good lawyer is your on-the-job training.

4. Specialize. By your mid 30s, if you don't have a specialty, it's hard to get your salary into the next bracket. You earn more money if your talents are more scarce. (Here's some information about how to specialize.) Also, don't give up hope if you have no idea what you're doing in your mid-20s. As long as you figure things out by the time you're 30, you will get a premium for 15 years of experience before your salary stops rising.

5. Buy a house assuming you won't get a raise. Ever. When it comes to houses in the U.S., the average age of a first-time buyer is 33. So people go through their 20s gaining super-high raises, and then people buy a house in their mid-30s with the assumption that the raises will continue. In fact, though, you should buy a house preparing for your real income to remain unchanged until age 55, when it is likely to go down.

6. Recognize your limitations. People eventually start to realize that they are not going to get to the very top. They see that only one out of 100 web designers is the director, and only one out of 50 directors is a VP. Al calls this the funnel effect, and he says many people recognize this and start to trade time for money; people see that chasing the increasingly smaller raises is not as fulfilling as doing a wide range of other things with their time.

7. Focus on maintenance. Most people in their 40s have a lot going on. Taking care of aging parents, young kids, community organizations—all these jobs are falling on people in their 40s, which means it's not a good time to be trying also to leverage one's highest earning power. So instead of killing yourself trying to earn more and more, be realistic and go into maintenance mode.

One of the most common but least-talked about career moves is to get to a relatively high spot and then see how much you can cut back in terms of effort and still maintain that level of salary and/or prestige. This seems like a reasonable strategy for a wide range of people. So do small experiments with cutting back early in your career because creating enormous efficiencies takes practice. And a nose-to-the-grindstone work ethic is not the training you need for this type of change.