When Nancy Pelosi is handed the Speaker’s gavel in January, it will mark another historic milestone in women’s progress. Americans have become accustomed, however, to women ascending to the highest offices in government. Two of our last three secretaries of State have been women. And Senator Clinton is widely assumed to be the Democrat’s frontrunner in the 2008 presidential campaign.

What about women working in the private sector? More than 40 years after Betty Friedan urged women to exchange their aprons for business suits, by many measures, women’s progress in the workforce has stalled. Certainly today more women work and hold more prestigious jobs than ever before: as of 2002, women accounted for 46.5 percent of the workforce and held more than half of managerial and professional specialty jobs. Yet few women make it to the very top of the business world. According to the nonprofit research institute Catalyst, just eight Fortune 500 companies have female CEOs, and women account for just 5.2 percent of those companies’ top earners.

Why is this? Liberal feminist groups, like the National Organization for Women (NOW), tend to insist that sexism and discrimination are the primary cause. Yet many individual women recognize that their choices– particularly the choices they make once they have children– make the difference.

A recent Newsweek cover story highlighted how many women who are best positioned to break through the proverbial glass ceiling willingly downshift their careers after having children. A Harvard Business Review survey of midcareer women with graduate degrees or college degrees with honors found that more than one-third had taken extended time off from work, with the average break lasting more than two years. Surveys have shown that women evaluating job opportunities place a lower value on pay than men do, focusing more on job characteristics like flexibility and personal fulfillment.

That’s good news. If women’s different choices and preferences explain the paucity of women in the Fortune 500, then it’s not a problem that needs to be solved. Many women sincerely prefer lives dedicated to raising their families over high-flying careers, and we should respect their choices.

Yet there certainly are women who wish it were easier to have both a career and raise a family. The Harvard Business Review survey, for example, found that many women who had taken time off wanted to get back to work, but had yet to do so.

Groups like NOW look to government to force businesses to make it easier for women to work and care for kids. They push for regulations that would require employers to provide longer leave, paid leave, and more subsidies for daycare. But these government mandates come with a heavy cost. Many businesses, particularly small businesses, simply cannot afford to pay workers on leave. Finding qualified temporary replacement workers can be disruptive and expensive, leaving business owners with difficult choices about how to make ends meet.

Some radical feminists try to encourage women to avoid the problems of balancing work and family by forgoing children. Linda Hirshman, author of “Get to Work: A Manifesto for Women of the World,” instructs women that they can have one child, but not two. Raising one child, if properly outsourced, need not get in the way of your career, but having two children is a mistake.

Fortunately for women, the private sector has more palatable ideas about how to solve the work-family conflict. Increasingly, employers are creating new ways to make it easier for women to continue working while caring for children and to transition back into the workplace after time off. Businesses aren’t acting out of concern for women: They believe these initiatives will help them attract and maintain a high quality workforce. In other words, it makes good business sense.

The prestigious consulting firm Booz Allen Hamilton’s adjunct program, for example, allows former full-time employees to take on discrete work projects. This allows the adjuncts to evaluate if they have the time to dedicate to a given assignment and select only the most appealing prospects. These workers not only earn money from these assignments, but maintain important connections and skills. Deloitte & Touche has created a program called Personal Pursuits which helps former employees stay connected both to their professional circles and to the company. New technologies are making it easier for women to start home-based businesses and telecommute to work.

There probably never will be as many women running Fortune 500 companies as men. But our market-based system ensures that companies will be competing to find new ways to attract and maintain the highly skilled female workforce. Now that’s progress.