One of the long-offered explanations for why more women aren't in leadership positions — but one day will be — is that women face a workplace version of Catch-22. Past research has shown that they are more likely to be hired and promoted into existing management jobs once a woman has already held a job at that level, breaking down the pre-existing barrier.

But what about when brand new management jobs are created, either because a company is growing, restructuring itself or changing its strategy? What kind of shot do women have at getting these posts?

The answer, according to recently published research by professors at the University of Arizona and McGill University, is that it depends on how many women already hold jobs at the top of that company. The number of newly created management jobs that are first filled by women increases with the number of female managers in the firm. This finding supports the idea that having more women in the pipeline begets even more women — that is, as long as the new jobs created for them aren't too risky to yield success.

The study, published in the journal Administrative Science Quarterly, examined management jobs at New York-based advertising agencies over a 13-year period in the 1980s and 1990s. The researchers chose to study advertising agencies because of the availability of the data, but also because of the industry's unique characteristics. One of these is that career ladders in advertising are relatively short, meaning people in the field are likely to advance not by methodically advancing within a particular firm, but by moving from a smaller or less well-known firm to a larger or more prestigious one. As a result, advertising agencies create many new job titles to hold on to their management talent.

The University of Arizona's Joe Broschak  and his co-author, Lisa Cohen, found that the greater the prevalence of women in management jobs within the agency, the greater number of new management jobs went to other women. Interestingly, the number of new jobs filled by men did not follow the same path. New management jobs created for men peaked when the proportion of female managers at the agency hit roughly a quarter, and then turned downward as the ratio of female managers continued upward.

Broschak's explanation: 25 percent is the point where there are enough women in management jobs for men to start feeling threatened, but not enough to affect how many new jobs go to women. At that point, "firms create new job titles that they assign to men to preserve men’s status," he says. "Changing demographics can lead to conflict."

His findings appear on the surface like a good thing: Having more female managers leads to more women getting new management jobs. These jobs might be for new business lines where there's a lot of growth or provide a chance to shine by going after a new strategic effort. It's also potentially a sign women feel more confident to ask for new opportunities and the creation of new roles.

Or not. A well-studied phenomenon known as the "glass cliff" shows that women are often put into leadership jobs where the odds are stacked against them, such as a crisis going on or a greater risk for failure. Newly created management jobs often pop up in this context, when firms need to define someone's job as cleaning up a mess or taking on a new high-risk venture.

It could also mean new roles are being created as a stop-gap measure for women. Broschak and Cohen went back and interviewed some of the agency executives who were part of the data. One of them relayed cases where the agency wanted to promote more women into management, but didn't think they were quite ready for the job. "It was kind of a stepping-stone role," he says. "You can interpret that as either a positive or negative story."

Still, the overall results likely point to encouraging news for women. "When women are not able to move ahead in firms, and when we don’t see women put into new positions, they become stagnant," Broschak says. "A little bit of risk is a good thing."

Read also:

Like On Leadership? Follow us on Facebook and Twitter.