Studies of factories have shown workers who try to work 10- or 12-hour days make more mistakes, are more prone to burnout, and are more likely to quit than those who work eight hours. As a result, cumulative disruption to factories can drag their productivity below the level achieved during normal hours. Studies of doctors, nurses and other professionals have found that after long periods of overwork, people are more likely to slip up, cut corners, cheat or mistreat customers and coworkers.

Overworked employees are also more likely to leave and more prone to chronic diseases. Losing highly-skilled workers costs companies time and money, as tasks go unfinished or projects slow while new workers are being recruited and trained.

Globally, employee burnout costs economies an estimated US$300 billion a year. And the human cost, in lost earning potential, happiness and creativity, is incalculable.

These apparently unproductive hours are actually when they have some of their sharpest insights. It also allows them to have longer, more sustainable careers.

But even if overwork is counterproductive, self-defeating and economically irrational, isn't it an inescapable feature of today’s 24-7 economy?

A sceptic may object: this sounds great, but what about profitability and client satisfaction?

Because they are more productive, do better work and are more creative, companies that shorten their hours actually become more profitable. And if this transition is explained properly, clients are fully supportive. They suffer the same problems of overwork and burnout, and watch these experiments to see what lessons they can apply to their own workplaces. I've studied 100 companies that have moved to shorter hours, and heard of exactly one client who dropped a company when it adopted a four-day week.

So how can the 996 companies make the switch to a more sustainable work culture?

First, the change has to start at the top. Changing corporate culture, worker expectations and the way companies operate requires leaders who have the courage to challenge conventional notions of productivity.

Second, workers must be free to identify and eliminate problems, and experiment with new tools to help them work more effectively. As one CEO told me, “A four-day week is a leadership-instigated change, but you really need everyone to take ownership of it.”

Third, companies need to root out inefficiencies and distractions. This means making meetings shorter, relying less on email and Slack, and most important, redesigning daily schedules to allow for long periods of uninterrupted, focused work.

Finally, the change must be communicated clearly to clients. Shorter workweeks aren't about neglecting clients; they are about doing better work on their behalf.

These changes aren't easy, but moving to shorter hours helps companies become more productive, creative and profitable. Figuring out how to do more in fewer hours, not more, carves out a more sustainable path for companies and individuals. And it’s far better than burning out.

Alex Soojung-Kim Pang is author of “Rest: Why You Get More Done When You Work Less”. His next book, “Shorter: How Companies are Redesigning the Workday and Reinventing the Future”, will be published in 2020