The situation arose from this conundrum: Left alone, will companies compete, or is regulation necessary?

In many parts of Europe, the government tries to foster competition by requiring that the companies that own the pipes carrying broadband to people’s homes lease space in their pipes to rival companies. (That policy is based on the work of Jean Tirole, who won the Nobel Prize in economics this month in part for his work on regulation and communications networks.)

In the United States, the Federal Communications Commission in 2002 reclassified high-speed Internet access as an information service, which is unregulated, rather than as telecommunications, which is regulated. Its hope was that Internet providers would compete with one another to provide the best networks. That didn’t happen. The result has been that they have mostly stayed out of one another’s markets.

When New America ranked cities by the average speed of broadband plans priced between $35 and $50 a month, the top three cities, Seoul, Hong Kong and Paris, offered speeds 10 times faster than the United States cities. (In some places, like Seoul, the government subsidizes Internet access to keep prices low.)

The divide is not just with the fastest plans. At nearly every speed, Internet access costs more in the United States than in Europe, according to the report. American Internet users are also much more likely than those in other countries to pay an additional fee, about $100 a year in many cities, to rent a modem that costs less than $100 in a store.

“More competition, better technologies and increased quality of service on wireline networks help to drive down prices,” said Nick Russo, a policy program associate studying broadband pricing at the Open Technology Institute and co-author of the report.

There is some disagreement about that conclusion, including from Richard Bennett, a visiting fellow at the American Enterprise Institute and a critic of those who say Internet service providers need more regulation. He argued that much of the slowness is caused not by broadband networks but by browsers, websites and high usage.