We tend to measure the influence of Rupert Murdoch's News Corp. in terms of the reach of Fox News or the circulation of the New York Post and the Wall Street Journal. But it is actually local television stations on which Murdoch has built his empire and increased his stranglehold on access to information.

He has done so, in large part, by taking advantage of a 1999 change in FCC rules that allowed a single company to own more than one television station in the same market. That arrangement, known as a duopoly, lets big conglomerates such as News Corp. buy up stations, reduce their staffs and consolidate newsrooms. Murdoch now has nine duopolies. According to Santa Clara University's Allen Hammond, a staggering 109 duopolies were created between 2000 and 2006.

The problem isn't just that control over the airwaves becomes concentrated; it's that such consolidation often results in the gutting of local news coverage. Duopoly owners tend to duplicate their local coverage and reduce the amount of airtime dedicated to community news. The subsequent lack of coverage gives local governments a free pass to operate without any real media scrutiny.

In New Jersey, for example, News Corp. owns both WWOR, northern New Jersey's local station, and WNYW just across the river in New York. In 2009, WWOR's only hour of local news was reduced to 30 minutes. And because so many news resources are shared between WWOR and WNYW (including, not incidentally, a co-anchor), very little of what is covered in the newscast focuses on northern New Jersey. As Sen. Frank Lautenberg (D-N.J.) complained to the New York Times, "We don't have a reliable station within our midst."

But media and democracy groups haven't taken that lying down. In 2007, a citizens' group called Voice for New Jersey challenged WWOR's license renewal. The FCC agreed to hold a public hearing and has since expanded its investigation to see whether News Corp. lied in filings about how much local coverage it actually offers and how many reporters it employs.

Duopolies are not the only gift the FCC has given to big corporate media. In 2007, the FCC relaxed its rules on cross-ownership, allowing a single company to own a newspaper as well as either a television or radio station in the same community. "The mogul's dream is the citizen's nightmare," The Nation's John Nichols wrote at the time.

Kevin Martin, the FCC chairman at that time, claimed that such rules would help newspapers and other local outlets survive in a challenging financial climate.

But Michael Copps and Jonathan Adelstein, the two Democrats on the commission, called the proposal "a wolf in sheep's clothing" and said it would result in less news, not more. "In the final analysis, the real winners today are businesses that are in many cases quite healthy," Copps said, "and the real losers are going to be all of us who depend on the news media to learn what's happening in our communities and to keep an eye on local government."

Then-Sen. Barack Obama and Sen. John Kerry (D-Mass.) asked the Appropriations Committee to deny funding for implementing the rules out of concern that it would reduce the number of minority- and female-owned stations nationwide. The rules have been challenged in court, and may soon be overturned; oral arguments in front of the U.S. Court of Appeals for the 3rd Circuit were heard at the end of February. But given the FCC's track record, it's an open question whether such a ruling would have a noticeable impact.

That's because the FCC has the authority to grant waivers to broadcasters if they can show that an otherwise prohibited merger is in the public interest. The FCC has shown a willingness, again and again, to disregard its own rules for the benefit of big media. In New Jersey, for example, News Corp.'s temporary waiver allowing it to own WWOR and the New York Post expired in 2008. But the FCC has taken no action.

While the relaxation of the duopoly rules still prevents certain TV station mergers (between two top-ranked stations, for example), broadcasters are circumventing them. According to Corie Wright of Free Press, these broadcasters are "entering into contractual agreements whereby they share news coverage and station operations, though they purport to maintain separate ownership structures. The arrangements result in duplicate coverage being aired on stations that are supposed to be competing for viewers." Complaints have been filed with the FCC; not surprisingly, the FCC has not acted.

The impact of media consolidation is not abstract. New Jersey has 566 municipalities, but the entire state has only two licensed commercial stations. When media conglomerates take control of those stations, consolidate their newsrooms, lay off reporters and duplicate coverage, it has the effect of creating a news vacuum across the state. Corruption goes unchecked. Local political issues with significant consequences go unnoticed. It also results in the decline of other important programming. According to a study by Children Now, duopoly stations decrease their amount of children's programming at four to five times the rate as non-duopoly stations.

It's time for the FCC to take its role and its obligations more seriously, to recognize that the public interest is not served by unchecked media consolidation. Access to news and information is fundamental to democracy; attempts to weaken it should be met with protest. If the FCC were doing its job, it would deny any further ownership waivers to News Corp. in New Jersey and elsewhere. And it would compel News Corp. to divest from any anti-competitive arrangement where a waiver has already expired.

Either the rules mean something in a democracy, or they don't.

Katrina vanden Heuvel is editor and publisher of The Nation. She writes a weekly online column for The Post.