So why do Americans fetishize hard work when the link between labor and economic strength is so tenuous? The bottom line is that productivity — driven by technology and well-functioning markets — drives wealth far more than hours worked. And very few jobs in developed economies nowadays are classic assembly-line positions, where working 20 percent longer will mechanically produce 20 percent more widgets.
Psychology plays a role here too: At least 40 years of studies suggest that people work harder if you limit their time to complete a certain task. In some cases, working too hard can actually reduce output. Long working hours are also associated with ill health, which means lost labor in the long term, as well as higher medical costs for employers and government.
A study of hospital interns found that young doctors who worked longer shifts made almost 36 percent more serious mistakes, like giving the wrong dose or the wrong medicine altogether to patients.
Working too hard has societal costs as well. Nearly two decades ago, Harvard University professor Robert Putnam warned that the "social capital" of the United States was decaying as Americans spent less time with family, friends, neighbors and community organizations and more time "bowling alone."
Over the last quarter of the 20th century, Putnam recorded a 58 percent decline in attendance at club meetings and a 43 percent drop in family dinners. He blames television and commuting for much of the decline. But note also that the hyperactive U.S. worker put in over 20 percent more hours at the office than the average French worker in 2011.
All that extra parental time at home might be why French kids are so much better behaved — rather than greater parental neglect, as suggested by the recent U.S. parenting hit "Bringing Up Bébé."