Ben Bagdikian is probably the most quoted, certainly one of the most acute, commentators on media ownership. In the first 1983 edition of his book, The Media Monopoly, he reported that “fifty corporations own most of the output of daily newspapers and most of the sales and audiences in magazines, broadcasting, books and movies.” Bagdikian asserted that this concentration is dangerous for democracy – that we would be much better off if there were a different owner for each of the country's 25,000 media outlets. In the 2004 edition, he reported something even worse for our society and for democracy: “Five global-dimension firms … own most of the newspapers, magazines, book publishers, motion picture studios and radio and television stations in the United States.”

Bagdikian's claims have not gone unchallenged. Benjamin Compaine, a respected economist and lead author of the most definitive book on media ownership in America, is possibly the most prominent scholarly critic of the view that existing concentration in the mass media is – or that likely future concentration will be – objectionable. Compaine challenges both Bagdikian's factual and evaluative claims. According to Compaine, the top five media companies collect 27.55 percent of the revenue in the media industry. Contrary to Bagdikian's claim, even the top fourteen together collect less than half. As for Bagdikian's claim about the increasing extent of concentration, Compaine observes that in his 1982 book, he listed 62 companies “as being a leading firm in one or more media industries,” while in the 2000 edition he lists 90 companies.