Writing for The New Yorker, James Surowiecki explores the downside of working long hours:
The perplexing thing about the cult of overwork is that, as we’ve known for a while, long hours diminish both productivity and quality. Among industrial workers, overtime raises the rate of mistakes and safety mishaps; likewise, for knowledge workers fatigue and sleep-deprivation make it hard to perform at a high cognitive level. As [David] Solomon put it, past a certain point overworked people become “less efficient and less effective.” And the effects are cumulative. The bankers [Alexandra] Michel studied started to break down in their fourth year on the job. They suffered from depression, anxiety, and immune-system problems, and performance reviews showed that their creativity and judgment declined.
If the benefits of working fewer hours are this clear, why has it been so hard for businesses to embrace the idea? Simple economics certainly plays a role: in some cases, such as law firms that bill by the hour, the system can reward you for working longer, not smarter. And even if a person pulling all-nighters is less productive than a well-rested substitute would be, it’s still cheaper to pay one person to work a hundred hours a week than two people to work fifty hours apiece. (In the case of medicine, residents work long hours not just because it’s good training but also because they’re a cheap source of labor.) On top of this, the productivity of most knowledge workers is much harder to quantify than that of, say, an assembly-line worker. So, as Bob Pozen, a former president of Fidelity Management and the author of “Extreme Productivity,” a book on slashing work hours, told me, “Time becomes an easy metric to measure how productive someone is, even though it doesn’t have any necessary connection to what they achieve.”
While several investment banks have been making an effort to curtail working hours, Surowiecki points out that changing expectations and norms will be necessary for a true culture change. One researcher, for example, told Surowiecki of a ”consulting firm that mandated that people stay out of the office on weekends, only to discover that they were working secretly from home. In a culture that venerates overwork, people internalize crazy hours as the norm.”