It's long been true that Americans take fewer vacation time than employees in other parts of the world, but the latest data suggests that we may be working towards overkill.

According to a new survey, 42 percent of Americans failed to take any paid vacation days in 2014. That's right: All work and no play seems to be the new trend for almost half of U.S.-based employees. The survey was conducted this month by travel industry blog Skift, which used Google Customer Surveys to get responses from 1500 American adult Internet users. Skift's poll showed that 13 percent of respondents could have taken up to 10 days of vacation last year but opted not to.

The benefits of taking paid vacation days are plentiful. Besides the fact that they're fun, vacations help boost morale, happiness and productivity at work. Even if they're not extended vacations, taking a one-time personal or mental health day can do wonders to reduce fatigue, fight off illness and keep employees excited to be at work.

These results come in the wake of a new trend in corporate management toward adopting an "unlimited" vacation policy, which means that employees can take as many days off as they wish, given they get all their work done and get pre-approval by their supervisors. Richard Branson has adopted this policy at Virgin, and so have a few startups like Netflix, Evernote and Eventbrite. Unlimited vacation policies have become a way for companies to place trust in their employees, as well as to boost their talent brand to help recruit top hires.

But unlimited vacation may be too good to be true. Last month Mathias Meyer, CEO of Travis CI, a Berlin-based app development platform, experimented with unlimited vacations at his company, only to revert back after it backfired.

"People will hesitate to take a vacation day as they don't want to seem like that person who's taking the most vacation days," he wrote on his company blog. "It's a race to the bottom instead of a race toward a rested and happy team."