Credit where it is due: the federal government’s decision to block the merger between Comcast and Time Warner was the right one. In the past, I have criticized the Justice Department and the Federal Communications Commission for failing to enforce competition laws vigorously enough. On this occasion, according to media reports, the staffs of the D.O.J. and the F.C.C. both concluded that a Comcast–Time Warner combine wasn’t in the public interest, and their bosses backed them up. That’s how things are supposed to work, and, coming on top of the F.C.C.’s decision to classify broadband Internet service as a public utility, it demonstrates that the regulatory environment in Washington has changed.

For years, it seemed that the cable industry, and Comcast in particular, had captured much of the U.S. regulatory apparatus. After the Comcast–Time Warner merger was announced in February, 2014, I posed a simple question: “Does Comcast Own Washington?“ It turns out that it doesn’t, and that’s very welcome. But it’s only a start.

The demise of this merger is unqualified good news for content producers, such as television studios, and for alternative content-distribution systems, such as Netflix and Amazon, which feared being bullied by a Comcast–Time Warner combination that would have dominated nineteen of the top twenty television markets in the country, and would have controlled up to forty per cent of the nationwide broadband market. Although Comcast gave assurances that it wouldn’t seek to exploit its enhanced monopsony power, the staffs of the regulatory agencies appear to have decided, quite rightly, that these promises were unlikely to have been honored. (My colleague Tim Wu has more on this.)

But what about cable and broadband customers? While preventing Comcast from ganging up with Time Warner was right and necessary, it won’t do much to help the tens of millions of people who live in areas where these two companies have monopolies, or cozy duopolies with Verizon or A.T.&T. These Americans pay substantially more for content and broadband access than residents of other advanced countries, and the reason why is pretty obvious: in many markets, there is little or no competition on price.

Big cable and telephone companies often try to obfuscate this fact (which the collapse of the merger won’t alter), but a number of independent analyses back it up. Take the market for broadband access: “Overall, the data that we have collected in the past three years demonstrates that the majority of U.S. cities surveyed lag behind their international peers, paying more money for slower Internet access,” the Open Technology Institute concluded in a report published in October. As for cable television, a recent report by the Consumers Union found that cable rates have risen by about thirty per cent in the past five years, which is nearly three times the overall rate of inflation.

Addressing this problem isn’t easy—tackling entrenched monopoly power seldom is—but there are several possible ways forward. One option is encouraging the growth of à-la-carte streaming-media options, and the F.C.C.’s net-neutrality ruling should help to do this. Many young consumers, particularly, are glad to “cut the cord” with their cable companies and watch television shows and movies on services such as Netflix, Hulu, and Amazon. The regulators should be encouraging growth in this area, and, generally speaking, they are.

The majority of Americans, however, seem keen to retain a traditional bundle of content and services, with broadcast television at its core. To prevent the cable and telephone giants from gouging these consumers, the best option may be to force monopoly (or duopoly) incumbents to open up their networks to competitors at cost, or near to cost. These new entrants can then offer alternative content packages, with different (and hopefully cheaper) pricing options.

In European countries, such as the United Kingdom, this policy, which is known as “local loop unbundling,” has had a big impact. New players have emerged, and prices have come down. In the United States, such a policy has never been properly enforced by the regulators. On paper, the Telecommunications Act of 1996 required the big telephone companies to lease their networks to competitors. In practice, however, the incumbents stalled, creating technical and cost barriers that made it prohibitively expensive for potential entrants. The regulators let this happen, and unbundling never really took off.

Now that Washington is getting serious about addressing market power in digital-media markets, it needs to return to this area, and also explore other options in its effort to encourage competition and protect consumers. Preventing Comcast from swallowing up Time Warner may well have prevented the current situation from getting any worse. But it hasn’t solved the underlying problem of entrenched local monopolies.