"Myopia, also known as nearsightedness, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry."
--National Eye Institute (NEI)

You're likely to make more than a handful of key job decisions in the long march of a complete career -- some thoughtfully planned, and some due to pleasant serendipity. But we can be prone to myopia as we move from position to position throughout a career, or remain past the shelf-life expiration date of a job we once loved.

Guess who doesn't suffer from nearsightedness when it comes to your career? The recruiter or hiring manager who sees your entire work experience of thousands of days reduced to a series of bullet points on a sheet of paper or a LinkedIn profile. They weren't around for the trees you witnessed up close; they truly only see the forest.

Illustration of cheerful businesswoman holding briefcase, running up an upward sloping graph with blue sky and clouds in the background.

Image source: Getty Images.

How often should you switch jobs -- and what frequency alarms human resources (HR) departments? If you want to get grounded in what's admittedly an extremely broad question, it's fruitful to be aware of job movement across the broader economy. The U.S. Bureau of Labor Statistics (BLS) publishes a biennial report on job tenure -- i.e., the length of time workers have stayed in their current positions.

The BLS last published its "Employee Tenure Report" in 2016. Per the study's findings, the median number of years which workers had been with their present employers in the baseline month of January 2016 was 4.2 years, down from 4.6 years in January 2014.

Perhaps not surprisingly, "Food services and drinking places" had the lowest employee tenure, at 1.8 years, while Federal government jobs boasted the longest employee tenure, at 8.8 years. 

It depends, part one

For all careers between these two poles, job-switching frequency is one of those topics where the best answer is,"It depends." As I put forward at the outset, your professional growth over the years always exists as an easily digested narrative that your next prospective employer will read and parse.

In any role, you should be able to extend your capabilities and demonstrate measurable value to the organization that employs you. Sometimes, both can occur in an extremely short amount of time (to recruiters and employers, "extremely short" usually means one year or less).

Thus, beware of stringing together too many compressed job stints. Even though you may have had good reasons for flitting from one job to the next, such a paper trail will cause a potential employer to wonder if you'll stay after the organization invests considerable resources in you.

Now for a rule of thumb: In most job categories, a one-year window surrounding the U.S. median job tenure creates a perfectly acceptable frame to most folks on the other side of the hiring process. In other words, it's generally OK to switch jobs every 3-5 years.

As for catalysts for a move, once you believe you've maxed out learning and compensatory opportunities, or heaven forbid, fall into career depression as I've discussed in a related article, it's probably time to look abroad for new adventures.

Want to be C-Level? Not everyone can put together the bona fides to become a chief executive of an organization, and the larger the organization, the steeper the hurdles you must leap. If you're working up the proverbial corporate ladder, numerous jumps early in your career won't necessarily hurt you -- but you must show tangible results, and your titles should reflect increasingly greater responsibilities.

By mid-career, you'll need to slow down -- 3-7 years in a meaningful role is par for the course. The reason is simple to grasp: Organizations that are hiring a CEO or CFO typically think, at minimum, in 5-10 year increments. That's because the long tenure of a highly qualified individual enhances stability and rewards the entire enterprise with economic value creation.

Longer time periods also apply to highly qualified professionals (architects, engineers, doctors, lawyers, CPAs, etc.) and academics. For example, 5-7 years in a single position is often expected at numerous points during your work history. For those over 25, the BLS' tenure report pegs the median tenure of highly skilled and academic jobs at 5.6 years.

Now, suppose you're a millennial working in a start-up or fast-moving services company, say in the advertising industry. Do different rules apply to you?

While it's true that the nature of work is rapidly changing, and average tenure across industries is declining according to a recent Deloitte study, millennials are staying in jobs roughly in line with other generations. The study reveals that millennials are staying put in pursuit of the same goals as their older peers: adequate compensation, stability, and opportunities to grow personally.

It depends, part two

Of course, everything we've discussed above falls into the realm of generalization. If and when you switch jobs, and how often, depends on numerous internal and external factors. It depends on your immediate needs and your temperament. It depends on your financial value in the marketplace, and whether you're getting the value you deserve.

And it depends on the economy. There'll be periods where you may feel lucky to be employed, regardless of your profession. Remember the financial crisis of 2008-2009?

Finally, I can say from personal experience and from reading innumerable studies over the years that it also depends on happiness. Those who are pleased in their positions tend to stay put. Those who can't reach a level of financial equity and personal fulfillment will move on, often with disregard to their length of tenure.