Fear of being replaced and work piling up coupled with a lack of employer support and communication is keeping Americans from using the time off they have earned, according to the new study, Overwhelmed America: Why Don’t We Use Our Paid Time Off? conducted by GfK Public Affairs and Corporate Communications (GfK) for the U.S. Travel Association’s Travel Effect initiative. Despite a universal acceptance of the importance of paid time off (PTO), 40 percent of American workers will leave vacation days on the table, sacrificing their health and well-being and adopting a “work martyr complex” to demonstrate their value. Workers cite returning to a mountain of work (40 percent) and the feeling that nobody else can do their work (35 percent) as the top reasons they leave PTO unused. The effects of a tough economy still linger, with one-third (33 percent) of respondents saying they cannot afford to use their PTO, and a fifth (22 percent) of workers expressing concern that they do not want to be seen as replaceable. Read the full release here.