Long Hours Worked by Economically Active Persons Age Twenty-Five to Fifty-Four, by Year, Education, and Gender
"A century ago, it was mostly factory workers who worked long hours; few office workers exceeded forty hours per week. While factory overtime became less common, office workers, especially managers and professionals, started staying late (or bringing work home)....As late as 1940, high school dropouts typically worked longer weeks than college graduates did. By 1980, that pattern had reversed..."—p. 123, Century of Difference