We all knowplaceholder that Americans are terrible at taking vacations. We use fewer vacation days than citizens of just about any other developed country, leave tons of paid time off unused, and even struggle to switch off when we do manage to get away.

As you'd expect, experts agree that's pretty bad for our stress levels and, over the longer term, our productivity. But a new study offers a more novel reason that not taking a proper vacation is a stupid idea--it actually costs you money.

Wait, what? How can not splurging on that glam hotel or long-haul flight be a negative for your budget? Most professionals would concede that not taking a vacation could add to their exhaustion, but they'd also argue that staying home at least saves them some money.

Not necessarily, insists the analysis paid for (unsurprisingly) by the U.S. Travel Association and conducted by Oxford Economics. While the sponsoring party of the research obviously has a horse in this race, the conclusions are still pretty interesting. The study authors crunched numbers to determine the economic value of all the paid time off (PTO) that Americans leave on the table, looking at the question from the perspective of the individual, the business, and the economy at large.

How much is an unused vacation day worth?

For those who receive PTO that can't be converted to cash or rolled over indefinitely, the cost of skipping your allotted number of days is pretty clear. "American workers lost a total of 169 million PTO days in 2013--1.6 per employee. These days could not be rolled over, could not be paid out, were not banked or used for any other benefit--they were purely lost," claims the report.

"The value of one forgone day, where workers are de facto volunteers for their employers, totals an average of $504 per employee. Therefore, the value of those 169 million lost days is significant--$52.4 billion in forfeited benefits," it concludes.

Business owners don't get paid vacation time the same way employees do, so they don't fall into this category, but they also take a financial hit because of our workaholic culture, according to this analysis. "Employers carry unused PTO days as a liability on their balance sheets--and this liability steadily accrues, year after year. When an employee leaves the organization, much of that unused PTO must be paid out to the worker. This 'PTO liability' ties up billions in capital that could be invested in expansion opportunities, new products and equipment, research and development, or employee recruitment, training, or retention programs," explains the report.

The other costs of vacation starvation

Apart from the direct cost of essentially working for free a few days a year (or holding on to employees' pay when they choose to skimp on vacation), the report also claims that failing to take enough holidays has other, broader financial effects.

"If American workers were to return to pre-2000 PTO habits, the U.S. economy would enjoy a massive windfall. Annual vacation days taken by U.S. employees would jump 27 percent, equivalent to 768 million additional PTO days and delivering a $284 billion impact across the entire U.S. economy, including $118 billion in direct travel spending alone," the report says.

While that figure no doubt causes cheering from members of the U.S. Travel Association, it doesn't take into account lost productivity from those days spent kicking back rather than working. But even those who don't work in travel have reason to suspect that taking more time off would be a net gain.

The business benefits of taking time off are clear and include increased efficiency, space for high-level strategizing, and a push to develop better processes. All of which taken together are probably way more valuable than whatever amount of work you'd be able to churn out those few extra (exhausted) days a year. So take a vacation already!