Senators John McCain (R-Ariz.) (L), and Charles E. Schumer (D-N.Y.) appear on “Face the Nation” on April 7, 2013. (CBS News/Chris Usher/Reuters)

On Sunday, NBC’s “Meet the Press” featured a segment called “Women in Charge.” The three women who lead Washington, D.C. — newly inaugurated Mayor Muriel Bowser, schools Chancellor Kaya Henderson, and Chief of Police Cathy Lanier — were interviewed about issues facing the District, as well as what it’s like to be a woman running a major city.

Regular viewers might have been surprised by the line-up. Panels of women in prestigious leadership positions are not common on the Sunday programs. One report last year found that men made up three-quarters of guests on the shows.

The prevailing wisdom is that bias against women contributes to their under-representation. For instance, a 2010 Politico story suggested that press secretaries for female members of Congress believe the Sunday morning programs “have a men-in-suits mindset that leads to familiar faces appearing over and over – and vital women’s voices being muffled.” On its Web site, the organization Name It. Change It. states that “Widespread sexism in the media is one of the top problems facing women.”

But my research suggests that this is not the case. Instead, I find that women tend to appear infrequently on the shows because of journalistic norms – such as the desire by the networks to create balance and conflict or to interview the sources they believe possess political power. Because women are less likely than men to possess these characteristics, they are less likely to appear on the Sunday shows.

How do I arrive at this conclusion? I examined every guest who appeared on ABC’s “This Week,” CBS’s “Face the Nation,” “Fox News Sunday,” NBC’s “Meet the Press,” and CNN’s “State of the Union” from January 2009 through December 2011. There were more than 1,000 individual guests who made approximately 4,800 appearances. The guests ranged from members of the administration to journalists to elected officials.

Consistent with previous research (but relying on a much larger set of data), I found that women — regardless of whether they are appointed or elected officials, journalists, or political activists — are less likely than men to appear as guests. The chart below shows the number of appearances by men and women on each of the shows. After accounting for repeated appearances, women comprise approximately one-quarter of the guests. This is true for all five shows; women’s representation never surpasses 30 percent on any of the programs.

Graph by Gail Baitinger

And this is the case within several different categories of guests. Whether elected officials (of which members of Congress make up the majority), journalists, activists, or others, men always outnumber women, as the graph below shows.

Graph by Gail Baitinger

But once we look beyond the overall numbers, journalistic norms, not sexism, appear to determine which political actors appear on these programs. The most frequent guests on the shows are legislators with the most expertise and credibility — such as congressional leaders and members of prestigious committees. Members of the party opposite that of the president also garner more attention because these shows strive for balance and members of the out-party do not receive the same publicity for their message as the White House does. From 2009 through 2011, the Sunday shows brought on a disproportionate number of guests from the Republican Party to counter the Obama Administration.

This does not mean that sex is irrelevant. Instead, it highlights the fact that women in the pool of potential guests are less likely than men to have the attributes and experiences that make them seem newsworthy. During the years of the study, women comprised only 16 percent of U.S. senators, held just 15 percent of the leadership positions in Congress, and occupied only 16 percent of the seats on prestige committees. In addition, 90 percent of the GOP conference was men. If high-ranking Republicans are especially attractive as guests, then women are especially challenged.

Particularly problematic is that prospects for gender balance in the future remain bleak. The key to increasing women’s representation on the Sunday shows is increasing the number of women who enter the political arena in general. Yet Jennifer Lawless and Richard Fox find that women are less likely to run for office than men, and there is nothing to suggest that the gender gap in political ambition will decrease among future generations. In addition, Lawless and Sean Theriault find that female lawmakers retire from Congress earlier than men do, meaning that fewer women serve in office long enough to take on the leadership roles that would make them attractive to the Sunday morning shows.

The gender gaps in political ambition and tenure in office means that substantial gains for women as news makers are likely years away. As a result, panels like the one we saw Sunday on “Meet the Press”will probably remain a rarity.

Gail Baitinger is a Ph.D. candidate in the Department of Government at American University.