Is the concept of a 40-hour workweek too radical for your company? In one survey — the 2015 Workplace Flexibility Study — 65% of participants said they believe their employers expect them to stay connected to the office, long after they leave for the day. Naturally, workers who are paid an hourly rate often welcome extra hours for extra pay, but at some point, many salaried workers feel exploited.

In some industries, 40-hour workweeks are now so unheard of that, when it happens, it’s newsworthy. Take for example, the financial services company that was profiled in a business publication because, at the end of an eight-hour workday, they send their people home.

Of course, companies and industries differ in their needs. Academic research shows that beyond a certain point, additional hours cease to add incremental productivity. Depending on the work and other factors, that point may be 40 hours for some companies, and higher for others. Stanford University labor economist John Pencavel has explored this topic extensively.

In a study entitled “The Productivity of Working Hours,” Pencavel analyzed findings from earlier research on the subject and concluded that in general, productivity per hour worked begins to fall off at 50 hours. So, for example, if hours are cut from 55 to 50, employers may see little change in overall production, but five additional non-working hours could make a big difference to an overworked employee.

Not all workplaces and working conditions are equal. In fact, Pencavel’s analysis looked at studies of manual laborers in a munitions plant in wartime England. The physical demands of that job, and the potentially devastating consequences of an accident caused by a fatigued worker probably don’t match the work environment at your company. But even in a service business environment, if long hours don’t enhance productivity something needs to change.

Here are some specific drawbacks of letting employees work too long, and how your company, as well as your dedicated employees, may benefit by telling workers to unplug from the job.

Wheels Spinning

People vary, but when they work too long, many simply get tired, have difficulty concentrating, and either spin their wheels trying to be productive, or just give up. It’s not unusual for an employee who feels he or she has to appear busy to do non-work activities, such as browsing Facebook, or coming up with make-work tasks that aren’t helpful. Not only do tired employees not add to productivity, but fatigue may result in more errors and accidents.

While neither of these issues is new or surprising, Pencavel observed that employers often disregard the negative impact on employee morale and on the bottom line. It might be better, he said to consider cutting back overtime hours and to view those limits “not as damaging restraints on management, but as an enlightened form of improving workplace efficiency and welfare.”

Divided Loyalty

There are certain jobs which, by their nature, make it critical for some employees to be reachable most of the time. Usually those jobs involve special knowledge or expertise that is essential to keep other employees and equipment from being idled.

Apart from those exceptions, setting an across-the-board policy for employee hours may be a tough task. What feels right to one employee may feel restrictive to the next one and result in divided loyalty. Those who feel you expect them to work too many hours may already have one foot out the door, looking for an opportunity that encroaches less on their personal lives. .

Then again, employees who thrive on long hours may still be revved up to work after eight hours. Rather than having such an employee take that energy to moonlight at a second job you may need to make exceptions.

Recruitment

If you decide to limit work hours for most or all of your staff, you may find an unexpected bonus. Once word gets around that you send workers home and don’t expect them to stay connected at the end of eight hours, you may find recruiting new blood is far easier.

One administrative services company in Pennsylvania highlights its strict 40-hours-a-week policy, which may explain why they were recently swamped with 663 applicants for three openings. Not only were there plenty of quality candidates, but many of those job seekers placed a higher value on limited hours than on the related pay.

What Should Your Company Do Now?

Sorting this all out may require that you take a fresh look at the mood climate among your salaried staff. Here are some questions you might want to ask to determine what specific changes would be helpful.

• How many hours are salaried employees currently working?

• Do salaried employees (or particular worker categories or departments) feel overworked?

• Whether real or perceived, do employees feel pressured to work more than 40 hours a week?

• Among employees who often work more than 40 hours per week, can you quantify how many additional hours they are working on the average

Asking the questions and getting reliable answers can be tricky. Employees will want assurance that they can answer honestly and still remain anonymous. You may need to enlist the help of survey professionals to craft a questionnaire that gives you useful information before you embark on a meaningful policy change.