A recent study shows that Americans are skipping more vacations than they have in decades. Think of it this way, if your boss asked you to work four days for free, chances are you’d say no but a study done by the University of South Florida says the average American worker does this every year when they work instead of taking the vacation time they earned. Oxford Economics took a look at our vacation habits for a study funded by the U-S Travel Association. According to the survey, we’ve dropped our vacation times by almost a full work week since the year 2000 – From 20.3 days of vacation a year from 1976 to 2000 – to 16 days in 2013. Going back to the original rate, the survey says, would be equivalent to 768 million additional paid time off days every year for all Americans.