In April 2008, as summer approached, the travel site Expedia released its eighth annual International Vacation Deprivation Survey, which looked at workers in the United States, Canada, the UK, Germany, France, Spain, Italy, the Netherlands, and Austria.

For Americans, the good news is, on average, employees reported having 13 to 14 vacation days, which is up from 12 in 2005! However, 31% of Americans usually do not use all their vacation days, with an average of three vacation days per year remaining unused. Expedia calculated that this amounts to 460 million unused vacation days in 2008 – worth approximately $65.52 billion! Expedia says that one in three American workers, or 47.5 million people, are "vacation deprived."

Canadians, meanwhile, had an average of 17 days – two fewer than they had in 2007! On average, Canadians didn't use one of these days.

But what about the European nations? North Americans can read 'em and weep: France, 37; Italy, 33; Spain, 31; the Netherlands and Austria, 28; Germany 27; the UK, 26. Only 20% of the French didn't use all their 37 days and they only left, on average, two days unused! Meanwhile, Italy, which has the second-highest number of vacation days among the polled countries, sees 47% of workers not using all their days, leaving an average of six days unused. On average, workers in the Netherlands, Austria, and Spain skipped four days; those in the UK skipped three; and those in Germany skipped two.

So why don't we North Americans take every one of our few vacation days?

For most, money is the strongest incentive to remain shackled to the job and to forgo some fun at home or abroad, especially since more and more employers are offering compensation in lieu of vacation time. And for those who are hourly employees, grabbing a few extra shifts means more money, often at overtime rates.

Work, on the other hand, seems like a less reasonable excuse for skipping a vacation. However, the poll found that some of the work-related reasons that hinder vacations are heavy workloads, a corporate culture that does not support employees using vacation time, and employees' belief that taking vacation time would be perceived negatively.

With staffing cutbacks across industries, some people feel obligated to continue working when they'd really rather be on vacation, because the pile of work waiting for them when they return makes them think twice about leaving in the first place. This may also be related to the poll's finding that 29% of American respondents had trouble coping with stress from work at some time during their vacation!