“The forty-hour week is there for a reason; it gets the best work from people. The first four hours of work are the most productive and, as the day wears on, everyone becomes less alert, less focused, and prone to more mistakes. In 1908, the first known study by Ernst Abbe,5 one of the founders of the Zeiss lens laboratory, concluded that reducing the working day from nine to eight hours actually increased output. Henry Ford, who studied productivity issues obsessively, reached the same conclusion and infuriated his manufacturing colleagues when, in 1926, he had the audacity to introduce a forty-hour work week. Subsequent studies by Foster Wheeler (1968), Procter & Gamble (1980), members of the construction industry, and many, many more show that, as the days get longer, productivity declines. No study has ever convincingly argued otherwise.6”
―
Margaret Heffernan,
Willful Blindness: Why We Ignore the Obvious at Our Peril