New Year's Eve has come and gone, but it's not too late to add one more item to your list of resolutions: Take more vacations.

On the surface, this may seem like a frivolous, indulgent goal. But not only is it important -- making time for regular trips with friends and family increases one's feeling of well-being, finds a new survey by Gallup – but it's difficult. A recent survey by Glassdoor found the average U.S. employee only takes 51 percent of their eligible vacation/paid time off.

That’s a real shame, because Americans who regularly take time off work to go on trips report significantly higher well-being than their counterparts who are glued to their work year-round. Interestingly, not only does this vacation-effect persist across income groups, but its impact is so profound that those who earn less than $24,000 a year but take regular trips report a higher well-being score, on average, than those who earn $120,000 or more annually but don't regularly take vacations. (The data comes from more than 148,000 interviews with Americans aged 18 or older conducted from January through November.)

Related: The U.S. Has Become the No Vacation Nation

While well-being is a somewhat hard to pinpoint term, it's important. As Gallup notes, previous research has tied well-being scores to health outcomes including life expectancy and a lower risk of obesity, while some studies suggest that taking time off positively impacts the brain and heart.

All of which means vacation time isn't just good for employees – it can be good for employers, too. Besides the health cost benefits, encouraging workers to actually use their vacation days can decrease burnout rates and increase employee retention.

So in 2015, let's all resist the urge to remain tethered to our desks and make vacation a priority.

Related: American 'Work Martyrs' Are Too Afraid to Take Time Off, Study Finds