Last week, two former CEOs who once topped Fortune's Most Powerful Women list won hotly contested California primaries. Carly Fiorina, ex-Hewlett-Packard (HPQ) now battles Democrat Barbara Boxer for her U.S. Senate seat, while Meg Whitman, who built eBay (EBAY), faces off against Jerry Brown for a chance to rebuild the teetering Golden State. Fiorina's and Whitman's wins signify the Year of the Woman, as many say, but the rise of women actually runs a lot deeper than politics. Harvard Business School's Nancy Koehn believes that America is at a key moment in which the economy has shifted to favor women. And that shift, she says, will yield major change in the way we live and work for years to come.

Guest Post by Nancy Koehn, Professor, Harvard Business School

Three-quarters of the seven million jobs that have vanished in the recession belonged to men. The male unemployment rate is now 9.8%, vs. 8.1% for women. The trend got Larry Summers, the President's top economic adviser, speculating recently, "When the economy recovers five years from now, one in six men who are 25 to 54 will not be working."

Ouch. While the decline in construction and manufacturing is hurting men in the workforce, expansion of health care and education is helping women. It also helps women that we are traditionally paid less (earning 22% less than men, on average). It's usually more profitable to keep a woman on the payroll than a man.

It helps to realize that this is not the first time that women's presence in the paid labor force has increased markedly. Since the onset of industrialization in the late 19th century, there have been at least three such moments.

The first was in the 1880s and 1890s when women -- particularly single women -- poured into factories, stenography pools, hospitals, and retail stores, typically to work as factory hands or clerks. By 1900, 5 million women, or 21% of the eligible female labor pool, worked outside the home. Men still outnumbered women in the workforce by four to one. By 1930, more than 10 million American women, or about a quarter of the possible female labor force, were employed.

This important shift expanded women's sense of their own power. It's not a coincidence that women earned the right to vote in 1920. This milestone came after more than two decades of organized activity from groups like the National Women's Trade Union League, formed to advocate for higher wages and better working conditions, and the National American Woman Suffrage Association. Other developments in women's place and power followed, including the introduction of female birth control and the increased influence women exercised as consumers, both in and outside the home.

The second major influx of women into the labor force came with World War II, when mobilization imposed huge demands on the working population. Between 1940 and 1944, almost 5 million women entered the paid workplace -- including 200,000 who joined the military. By the end of the conflict in 1945, women comprised almost 30% of America's workforce. Many had jobs formerly held by men. In fact, the 16 million women working in the late 1940s marked, in absolute terms or as fraction of the eligible population, the highest level of labor force participation by women in U.S. history to date.

Again, the surge had big spillover effects: most notably, the women's movement, which began in earnest in 1963. That's when Betty Friedan's The Feminine Mystique arrived. The movement established women as the major actor in household consumption and financial decision, and increasingly on the political stage.

Another shift began in the 1970s. Between 1970 and 1990, women's participation in the labor force climbed from 42% to more than 57%. By the early 21st century, women filled half of the nation's professional and managerial positions. Yes, men still claimed more than 90% of the highest titles in Fortune 500 companies. But as Fortune has noted in its annual Most Powerful Women rankings (where $1 billion in revenue used to get an executive onto the list, and now it takes about $6 billion), women have gained significant corporate clout in the decade or so.

It's clear that the current "mancession," as I like to call today's malaise, will have reverberations for families, organizations, and society. The latest class of powerful women includes a number prominent whistle blowers and watchdogs. They speak up when established institutions or systems lose their way. There's a powerful group of them in Washington: SEC Chairman Mary Shapiro, FDIC head Sheila Bair, and Elizabeth Warren, the chair of the Congressional Oversight Panel created to investigate the bank-industry bailout. Warren has been a leading advocate for the creation of a Consumer Financial Protection Agency.

We see similar behavior in Meg Whitman and Carly Fiorina, the two former Fortune Most Powerful Women who last week won heated primaries in California. These women are political newcomers -- outsiders who vow to fix the state and the system that the veteran pols have messed up. Today, with Nancy Pelosi as Speaker of the House and Hillary Clinton following two female Secretaries of State, women are making major gains. The "mancession" will accelerate the trend. We don't have a female President -- yet. It's a matter of time.

Nancy F. Koehn, an authority on leadership and business history, is the James E. Robison Professor of Business Administration at Harvard Business School. Her latest book is The Story of American Business.