Richard Branson created a stir last week when he blogged about how "perplexing" it was to read Yahoo CEO Marissa Mayer insist that her work-at-home employees start showing up at the office by June or give up their jobs.

Trusting people without supervision, he said, is what delegating is all about. Branson wrote: "If you provide the right technology to keep in touch, maintain regular communication, and get the right balance between remote and office working, people will be motivated to work responsibly, quickly, and with high quality." 

The only point Branson missed, I would say, is that this isn't true for all employees. It's just very true for most of your best employees.

Research Supports Branson's View

The survey research I did for my book Business Brilliant uncovered a huge chasm between the way ordinary middle-class workers and super-successful millionaires use their professional time. More than 70 percent of middle-class workers agree with this statement: "I would rather work only during business hours, even if it means I don't have any control over my time during those hours."

By contrast, more than 80 percent of extremely-successful millionaire respondents don't mind working outside of business hours, so long as they get to decide how and when they use their work time. They agree with this statement: "I would rather have control over how I spend my time (able to participate in personal matters during the day), even if it means I have to work longer hours and work nights and weekends."

The upshot? When asked how much time they worked each week, the first group averaged 42 hours and second group averaged 62 hours! Females with a net worth between $1 million and $10 million logged the longest weekly work hours: 70. (Females in both groups, by the way, worked longer hours, and were more likely to want flexibility in their schedules than men.)

So I'd say your hardest-working, most highly-motivated employees also most value the freedom to come and go as they please. Flexibility is least important to your clock-punchers, people who want to go home at 5PM and forget all about work.

The Clock-Punchers Vs. the Flex-Time Workers

A 2001 study by a Brigham Young University professor points to the reason why.

Researcher E. Jeffrey Hill studied more than 24,000 employees at IBM, a company that has been exceptionally successful in retaining highly productive remote workers. The study concluded that employees with higher flexibility in their work hours are able to work longer hours before they experience what Hill defined as "burnout" in work-life balance.

According to Hill's study, IBM employees who kept regular office hours reached their levels of burnout at an average of 38 hours of work per week, while telecommuters who enjoyed flexible work schedules logged 57 hours per week before hitting that wall. The partial title of Hill's paper is: "Finding an extra day a week." The math suggests it's more like an extra two days a week.

The people willing to give up control over their working hours can't possibly work much more than 40 hours a week without destroying their home lives. But if you give workers flexibility (motivated workers that you trust, Branson would caution), you can get up to 40 percent more productivity from them--and not drive them crazy. 

What Works for You Works for Them

Branson may not pore over productivity studies like these, but he leads from personal experience. "Yours truly has never worked out of an office, and never will," he blogged. He doesn't expect his employees to punch a clock because he's never punched a clock.

Mayer is a different breed. She was Google employee No. 20, and made her way to the top by putting in long hours at the office. But you can't really say she's leading by example when it comes to work-life balance. Mayer is the mother of a newborn baby, so she had a nursery built into her executive suite at Yahoo, ensuring that her infant, and nanny will both feel right at home during office visits. 

As one Yahoo spouse grumbled to "I wonder what would happen if my wife brought our kids and nanny to work and set 'em up in the cube next door?" It's one thing to take away people's autonomy and flexibility. When you combine that edict with a do-what-I-say-and-not-what-I-do leadership style, you're practically begging your best workers to pack their bags.