The conventional division of media into publicly and “privately” owned is arguably outdated in an era of corporate media ownership. To own a newspaper or a broadcasting station has long been an expensive undertaking. But to describe media as “corporate” is not just to say that the media are owned by large companies. The striking development of the last quarter of the twentieth century was the diversification of media companies into other business interests and the acquisition of media companies by corporations active in other types of economic activity.

The second of these developments slightly preceded the first, with US firms such as Westinghouse and General Electric acquiring media houses. The acceleration of a communications revolution spurred the second development, with media companies holding diverse portfolios in broadcasting, newspapers and magazines, book publishing, cinema, sound recordings, computer software, and the internet.

The result of these developments has been a media landscape that is far removed from the ideal of the neutral “fourth estate” – press that are independent and detached from the political process. The media owners have a partisan interest in the political process in the same way that any company will have.

Many theoretical models have been developed to explain the role of the corporate media in the political process. The “propaganda model” developed by Herman and Chomsky is influential. [Edward S. Herman and Noam Chomsky, Manufacturing Consent: The Political Economy of the Mass Media, 1988] They explain the tendency of the mass media to conform to the political consensus in Western countries with reference to five “filters” through which all news passes:

• Ownership: mass media tend to be owned by large corporate interests with a vested interest in the political and economic status quo.
• Advertising: most income derives from advertising, not sales. Advertisers are themselves large corporate interests that disapprove of dissenting voices.
• Sourcing: there is a preponderance of official or “establishment” sources for political and economic stories.
• Flak: Critical reporting is met by a systematically hostile response from government and corporate officials, including lawsuits, informal pressure, withdrawal of advertising, or placing of damaging stories.
• Ideology: Herman and Chomsky described anti-communism as a shared and guiding ideology in the US media of the 1980s. This could be updated as an anti-terrorist, anti-Islamic or pro-globalization ideology in Western societies of the 2000s. Of course, other societies have their own official ideologies.

Herman and Chomsky were heavily criticized for the allegedly conspiratorial nature of their explanation. Actually they were at pains to point out that theirs was a structural explanation that operated independently of the individual choice of the editors and journalists involved. Whether or not the explanation is accepted, it is clear that the political role of media corporations is a fact of life in the twenty-first century.