This is a rare thing: a column on a topic I haven't covered before. With 185 Tooling Up columns since 1997, it isn't always easy coming up with something new.
In Tooling Up, columns are generally focused on helping you land a job. This month, I am writing about why some people leave jobs they worked so hard to find.
I see a lot of CVs. For years, I’ve noticed that some people—a lot of people, actually—don't stay very long at their first jobs. They may accept the job intending to retire there in 30 or 40 years, but instead they leave quickly, adding an early blemish to their CVs.
There are some good reasons to leave a job early. The job may have been misrepresented. Your boss might be a bully, or just a jerk. Or maybe you got another offer that's too good to refuse.
Those who don’t bail out early—who hang in and use that first job as an opportunity to learn, grow, and show stability—usually end up in a much better position. I’ve seen how far employers stretch to land candidates with solid work histories and significant stays at each employer.
These days, people don’t stay in companies for a lifetime as they did in the decades after World War II, but a series of 1- or 2-year stays will still hurt you. Five to 7 years at a company is a good run. Consider 2 to 3 years the minimum commitment when accepting a new job.
Want to learn more about determining if you're a good fit for a company? Read "Tooling Up: Forecasting the Fit." 
One short stay may not be a problem if you have a convincing explanation. But if short stays start to seem like a trend, you’ll earn the job-hopper label. You'll need to explain yourself at every future job interview, and there will be few enough of those.
A few years ago, I read a book offering explanations for why people leave jobs. In The 7 Hidden Reasons Employees Leave, Leigh Branham lists and explains these seven reasons. Branham’s intention is to help employers improve employee retention, but those reasons are worth thinking about for employees and job seekers because knowing them may help you look at job offers more critically.
Here are Branham’s seven reasons, with my own commentary about how these apply to readers looking for their first real job:
1) The job or workplace was not as expected: This may be the most common reason for early departures, so make sure that you know what your expectations are. Identify your prime needs prior to the job interview. Then test the job against those needs during that interview. What you learn will help you make a well-informed, unbiased decision about whether it makes sense to take the job. It may be hard to turn down what seems like a good job offer at a time when job offers are rare, but it's much better to refuse an offer than to inject a short stay into your employment history.
2) The mismatch between job and person: Branham’s research shows that more than 80% of workers feel they do not use their strengths every day. That can be very frustrating for the employee, and counterproductive for the employer. Identify your strengths before the interview. Ask questions to uncover whether your strengths will be utilized. If not, you will perform below your potential and enjoy the work less.
3) Too little coaching and feedback: In order to stay motivated and engaged, people need to know they are on the right track. Branham says that just 35% of highly talented employees believe their companies keep them well-informed about where they stand.
When you are interviewing, ask your prospective boss questions like: “How do you help your employees reach their personal development goals?” and “What systems are in place to coach staff members and provide feedback?” A hands-off boss may sound great, but for most people it’s not a good situation for the first year at the company. Early on, you need mentoring.
4) Too few growth and advancement opportunities: Even in a flat organization, employees who perform well should be able to achieve career growth, recognition, and self-satisfaction. Often, an employee leaves quickly because she can’t see what her career path looks like, or because expectations are unrealistic. It takes about twice as long to earn a promotion than most new employees expect.
Your new manager, backed by the human resources department, should address those expectations by outlining a typical career trajectory for someone in a position like yours. But often that doesn't happen. Expect to spend 2 to 3 years learning how the company works, though it may be longer before opportunities arise. Don’t expect to occupy a corner office without putting in some time and sweat equity.
5) Feeling devalued and unrecognized: Managers often tell me that their new employees are “needy,” which isn’t a good thing. Apparently, after years of being treated like mushrooms—kept in the dark and fertilized with manure—even former academics expect to be pampered when they move into a company. The reality is exactly the opposite: Their efforts often go unrecognized.
The solution is to find your own ways to feel good about your job performance without a change of scenery. This is a very common problem . Until you solve it, you’ll be job-hopping.
6) Stress from overwork and work-life imbalance: Stress can pile up as a result of long hours and deadline pressures. After graduate school and maybe a postdoc, a long workweek may not scare you—but how much experience have you had dealing with real deadlines? My guess is that this will be one of the first rude awakenings you’ll have during your first year in industry.
According to Branham, fewer than 30% of employees believe they have a healthy balance between their work and nonwork lives. Many companies are aiming to address this by developing programs for improving employees' work-life balance. Yet, lean times mean more work for those employees lucky enough to have jobs, exacerbating an already challenging situation. It's up to you to figure out how to get the work done and still have a satisfying life.
7) Loss of confidence in leadership: In some companies, a combination of layoffs, financial scandals, and absurd pay gives employees the impression that CEOs are helping themselves at the trough at the expense of the other employees. But that's not why people leave their jobs early. People leave because they have a poor relationship with their supervisor, not with the CEO.
In one of his earliest columns for Science Careers, David Jensen wrote about how to select your new boss .
If your boss isn’t the kind of person who you’d trust with one of your ideas, or if you have no confidence that your work is adequately represented to higher management, you might be headed for the door—but don't be hasty. Are you sure you're right about your boss? Can the relationship be improved? If not, is an internal transfer available? Explore every possibility to get out from under a boss you don’t trust, short of leaving the company.
According to Branham, money rarely causes people to leave their jobs. Higher compensation is nice, but apparently it isn’t the key to employee retention.
But in my experience, the linkage in the other direction is strong: Employee retention—that is, staying longer at your job—leads to better future offers. So, aim to take full advantage of every position you accept during your career, especially the first. If you succeed, your paychecks will be consistently higher.