Employee turnover is a major concern for employers -- no matter the state of the economy. And for good reason. It's frustrating, time-consuming, and expensive to deal with.

Several studies have found the total cost of losing an employee could range from tens of thousands of dollars to 1.5-2X the position's annual salary.

The high cost is due to the price of hiring, on-boarding, training, lost productivity, and business errors. Business owners could add to this list of what they have lost besides the employee.

Business owners and supervisors should be aware of the signs that an employee is about to quit. Another study on voluntary employee turnover was conducted by Tim Gardner of Utah State University's Jon M. Huntsman School of Business.

Included here is some additional research on the subject. These behaviors can help you identify when an employee is going to leave you out in the cold.

1. No longer commits to long-term projects

When an employee has made the decision to move on from an organization, she's less inclined to commit to a long-term project. It could prevent her from meeting her departure date.

The employee would prefer to wrap up her current workload so she can leave free and clear.

2. More active on LinkedIn

Jennifer Winter, a career consultant, posts on the Muse. She says that "when you see an employee constantly on LinkedIn, it probably shouldn't raise any red flags. However, a sudden uptick in new connections, groups joined, or articles shared could be an indication. Your employee is trying to boost his or her social profile--and find his or her next big thing."

Building new connections on LinkedIn, visiting job search sites, or researching other companies is an indication that someone is ready to quit.

3. Contributes less during meetings

If an engaged employee suddenly becomes less active during meetings, it may be an indication that he or she is leaving. Maybe the person used to provide great insights or contributions.

This is a pretty solid indicator that something is going on. It may be a family or personal crisis, but in any case, you should care.

4. Wants to attend conferences or workshops

Not everyone has the desire to attend conferences or workshops. The employee who has never expressed interest in attending them but suddenly starts to go could just be hoping to strengthen his or her skills or knowledge or might be trying to become more visible.

If there's someone who previously expressed interest in conferences and workshops but is now indifferent, that could also be a bad sign. Maybe the person's not interested in developing any new skills or knowledge that could benefit your organization.

5. Is absent a lot

An employee who rarely called in sick or took an extended vacation is now hardly ever in the office. That's another sign someone's disengaged. Maybe the person is searching for new employment opportunities, using up acquired time off, or maxing out his or her benefits.

6. Acts more reserved or quiet

Once an employee decides to leave, he or she is going to act more reserved or be quiet during meetings or company activities.

7. Starts taking more personal calls

Does the employee frequently leave meetings or her workspace to take personal calls? That phone call could be her dealing with a family emergency or speaking with another employer.

Don't make assumptions. But if this becomes frequent, it's a red flag that something is awry.

8. Was recently passed over for a promotion or raise

An employee who feels frustrated, discouraged, and undervalued may be motivated to look for a job where she feels more appreciated.

9. Is less interested in advancement

Everyone strives for job advancement -- remember, it makes a person feel valued. If that goal no longer seems important to an employee, then he's probably looking for a position elsewhere.

10. Has stagnated in his or her position

According to a great study by Glassdoor, "Every additional 10 months an employee stagnates in a role makes them 1 percent more likely to leave the company. ... At that point, they finally move on to their next position."

11. Has had a major life change

Major life changes shake things up. These include getting married, divorced, having children, taking care of a sick family member, or purchasing a home. Each of these situations can influence whether an employee chooses to stay at or leave your company.

For example, having a child may force someone to look for a job that pays more money. Taking care of a loved one could make a person look for a job he can do remotely.

12. Productivity has dropped

Has your normally productive, reliable, and punctual employee suddenly become less productive or dependable? "Any behavioral changes that point to 'presenteeism' -- the phenomenon of employees showing up at work without being fully present -- are huge red flags" that someone's going to quit, says Michael Kerr, an international business speaker and author of The Humor Advantage.

13. Work friends are jumping ship

In a study conducted in the U.K., "57 percent of respondents said having a best friend in the office made their time at work more enjoyable. Almost a third stated they were more productive. One in five said it boosted their creativity."

Six in 10 employees stated that happiness was more valuable than salary. If an employee leaves a workplace, likely friends there will be following her out the door. In some situations, the employee that left may even recruit friends at the old workplace to join her at her new job.

14. Not interested in pleasing his or her supervisor

Another behavioral change to note is if an employee is no longer interested in pleasing his supervisor. If he previously stayed late or took work home with him and doesn't do this now, that could be a big indication he wants out.

15. Has friction with another employee

As noted earlier, workplace relationships are important. That's why if you notice a toxic relationship brewing between two employees, there's a good chance one of them is going to walk.

16. Avoids social interactions

Has the employee been avoiding social interaction with her supervisor or other management more than usual? It's another red sign that someone's ready to quit.

17. Delegates assignments to others

Has one of your team members suddenly started delegating his work to others? Unless this has been authorized by management, there's a good chance the employee already have one foot out the door.

18. Is not suggesting innovative ideas

When an employee shares new helpful ideas or innovative approaches, it's a sign she's engaged. It shows she wants to be a valuable member of the organization.

Has she stopped bringing up new ideas or suggestions? You can be certain she's no longer interested in the improvement of the company.

19. Is taking longer breaks

Breaks are essential -- and required. If you notice that an employee is taking more frequent breaks or longer lunch breaks, he's likely disengaged. He may be spending that time having lunch meetings with potential employers.

20. Makes exact arrivals and departures

If previously an employee would arrive early, leave late, or be a volunteer for an extra project, it's a red flag if now the employee arrives and leaves at an exact time or shows up chronically late. Note if he always leaves early--you can be certain that he's leaving your company.

21. Has started complaining

"If a typically happy and contented employee is suddenly complaining, take a closer look," the Employers Association of the Northeast states. "Is the complaint about the employer, policies, or management decisions? This is usually a sign that something is amiss. A disengaged employee is likely seeking a new opportunity and may also be spreading discontent among others."

22. Has just received a degree, license, or certification

Sometimes, an employee obtains a new accreditation to become a more valuable member of your company. But there are other cases. Sometimes an employee is working on or has completed a degree and doesn't say anything.

Normally, further education is a sign an employee is making himself more attractive for potential employers. After all, why else would he invest the time and money to improve himself when he's stuck in his current position?

23. Has become secretive

Is an employee exhibiting secretive behaviors at work? Does she block her computer screen? How about covering papers, or keeping her office door closed more than usual?

It could be because she's surfing job sites or distancing herself from everyone else.

24. Has stopped returning phone calls or emails

"If one of your team members is contemplating resignation, they're less likely to communicate often. Less email, in-person time, or just in general," says Lynn Taylor, a national workplace expert. She wrote the book Tame Your Terrible Office Tyrant: How to Manage Childish Boss Behavior and Thrive in Your Job.

Taylor adds, "The thinking is that, to the extent they're less accessible, they won't risk being put on the spot. Answering sensitive questions that could jeopardize their job when they're not yet ready to move."

25. You've got a bad feeling

Science has proved that "trusting your gut" isn't a metaphor. If you've got a sinking suspicion that all is not well with an employee, there's a good chance that you're not wrong.

Tips on Preventing Employee Turnover and Improving Employee Retention

Being aware of the signs that someone is about to quit is only the first step. It's up to you to prevent these behaviors from happening in the first place, by:

  1. Selecting the right people for your organization from the get-go. Use behavior-based testing and competency screening. Make sure a candidate is also a good fit with your company's culture.
  2. Hiring the smartest people you can find and allowing them to wear multiple hats.
  3. Offering an attractive, competitive, comprehensive benefits and incentives package that includes components such as life insurance, disability insurance, and flexible hours.
  4. Showing appreciation -- even a handwritten thank-you note is effective -- and celebrating team wins.
  5. Providing opportunities for employees to share their knowledge -- for example, writing company blog posts. Provide opportunities for career and personal growth through training and education.
  6. Making the workplace fun and safe -- such as having company activities. Address any friction between employees before it escalates.
  7. Involving employees in making important decisions.
  8. Clearly communicating goals, roles, and responsibilities.
  9. Implementing an open-door policy.
  10. Encouraging employees to have friends at work.