Lack of adequate sleep is costing the average U.S. worker 11.3 days, or $2,280 in lost productivity every year, according to a study in the September 1 issue of the journal Sleep. As a nation, the total cost is 252.7 days and $63.2 billion. Americans are not missing work because of insomnia. They are still going to their jobs but accomplishing less because they’re tired. In an information-based economy, it’s difficult to find a condition that has a greater effect on productivity.” The results were computed from a national sampling of 7,428 employees, part of the larger American Insomnia Study, which was led by Kessler.