Workers in the U.S. took an average 17.2 days of vacation in 2017, the highest level in seven years, researchers said.
Despite the increase, the average American employee is still not using up his or her annual allowance of vacation days, according to a study from campaign group Project: Time Off.
The data revealed that the U.S workforce remains reluctant to use up its annual leave allowance. Fifty-two percent of Americans said they had lost vacation time that went unused in 2017, while 24 percent said they hadn't taken any paid leave in more than a year.
Those figures are well below the average 20.3 vacation days taken by U.S. workers each year between 1978 and 2000.
According to the survey, U.S. employees who were concerned that taking vacation would make them appear less dedicated were dramatically less likely to use all of their annual leave. The same trend was evident for those who felt that their workload was too heavy or that no-one else could do their job.
America's unused vacation time was a $255 billion missed economic opportunity that had the potential to create 1.9 million jobs, the researchers said.

Report author Katie Denis said a reluctance to travel when taking vacation was also in evidence, with workers using on average a lowly eight days a year for trips away.
"When we forego travel, we miss out on defining moments, experiences and memories, and end up costing our economy," Denis said in a press release Tuesday.
There is no statutory minimum paid vacation or paid public holidays in the U.S. This is left to the employers and employees to negotiate as part of the employment agreement.
In comparison, a French or Danish worker can expect a statutory 36 days a year of paid vacation, including public holidays, compared with 28 days for workers in the U.K. and 34 for workers in Sweden.
The Project: Time Off survey questioned 4,349 U.S. employees and was carried out by GfK. Additional economic analysis was provided by Oxford Economics.
