Hang on to those talented women!

It's Friday night and the hazy summer sun has long since retreated. I'm on the couch, alone. Working.

Don't get me wrong. I'm not asking for sympathy. Oh no, on the contrary. I'm young! I'm free! I can work as much as I want! And like a Tropicana machine, I squeeze time out of my day to do just that.

By my calculations, I can spend an extra 47 minutes working toward my career goals if I opt for a PB&J sandwich instead of cooking a real dinner. And if I download German radio programs on my iPod shuffle, I can chip away at a third language on my three-mile walk home and get exercise. Then I'll have more of the evening left for reading hefty history books, which, incidentally, provide a nice weightlifting workout if one holds them properly.

But life-goals I cherish deeply – like raising a family – will most likely require me at some point to exit this autobahn of career advancement. And that thought has more than once left me forlorn, wondering how I will ever negotiate what Sylvia Ann Hewlett so aptly describes as the "off-ramps" and "on-ramps" of my career, while staying true to my ambitions both at home and at work.

So it was that, one Friday evening, I eagerly picked up her new book Off-Ramps and On-Ramps: Keeping Talented Women on the Road to Success. And as I did, I almost immediately made a happy discovery: that rather than primarily addressing women like me, Hewlett – economist and author of several other books including "Creating a Life: Professional Women and the Quest for Children" – was aiming her message at business leaders.

In fact, that's what is most refreshing about Hewlett's book: Rather than launching a plaintive feminist argument against the rigidity of male-oriented career models, "Off-Ramps and On-Ramps" presents a convincing economic case for offering more flexible work arrangements to highly qualified women.

Though Hewlett's writing is not as concise as her busy audience deserves and not all the data she uses to back up her theories is not always as relevant as it should be, on the whole she offers a thesis that is both solid and compelling.

With H1-B visas harder to get and countries like India and China wooing many expats to return home, the talent pool for highly skilled labor is being stretched thin Hewlett argues.

Women, who are graduating at higher rates than men from undergraduate, graduate, and many professional programs, constitute the most concentrated pool of highly talented labor. Savvy businesses willing to adapt to women's unique aspirations and constraints will reap tangible economic benefits as a result, she says.

The data Hewlett offers is admittedly persuasive. Consider that:

•The future talent pool of highly skilled workers in many fields will be disproportionately female: Women earn 59 percent of US bachelor degrees and 60 percent of master's degrees, though they lag in doctoral programs.

•As the "chief instigators" behind 83 percent of all consumer decisions, women make invaluable members of product development and marketing teams.

•Sixty percent of highly qualified women have nonlinear careers, and 37 percent of them leave their careers – only for an average of 2.2 years – but they often have difficulty ramping back up.

•The cost of hiring a replacement for a woman who off-ramps averages 150 percent of her annual salary, and can run as high as 300 percent. So in many cases, it pays to be flexible during those average 2.2 years and keep her on the payroll.

The second half of Hewlett's book focuses on specific solutions business leaders can implement to retain highly qualified women (everything from seasonal flexibility to networking and mentoring to finding ways to gratify women's desires to give back to society), peppering the chapters with at-a-glance boxes that highlight company success stories.

While some are unpersuasive, other case studies, like those of the British communications firm the BT Group, are certainly impressive. Since introducing a radical approach to flexibility, the firm has seen its labor turnover drop to 3 percent. Ninety-nine percent of women return after maternity leave, compared to the national average of 47 percent – a statistic that saves the company £5 million ($10 million) a year. The company was so successful, in fact, that it provided a model for Britain's employment act of 2002, Hewlett says.

It's also part of the Hidden Brain Drain Task Force, an initiative launched several years ago by Hewlett's Center for Work-Life Policy in New York. The task force – which has attracted other large corporations such as American Express, Goldman Sachs, Intel, Microsoft, and Time Warner – has developed many of the strategies and produced many of the case studies Hewlett cites in her book.

More information and networking resources are available at worklifepolicy.org. Click on it some Friday night over PB&J.

• Christa Case is an editor in the Monitor's international news department.