Duopoly
A true duopoly is a form of oligopoly where only two producers exist in a market. In reality, this definition is generally eased whereby two firms must only have dominant control over a market. In the field of industrial organization, it is the most commonly studied form of oligopoly due to its simplicity.
Duopoly Models in Economics
There are two principal duopoly models, Cournot duopoly and Bertrand duopoly:
- The Cournot model, shows that two firms assume each others output and treat this as a fixed amount, and produce in their own firm according to this.
- The Bertrand model, in which, in a game of two firms, each one of them will assume that the other will not change prices in response to its price cuts. When both firms use this logic, they will reach a Nash Equilibrium.
Politics
Modern American politics has been described as a duopoly since the Republican and Democratic parties have dominated and framed policy debate as well as the public discourse on matters of national concern for about a century and a half. Third Parties have encountered various obstacles to getting onto ballots at different levels of government, more so in recent decades.
See List of political parties in the United States for a more comprehensive look at the politics of the Two-party system, Duverger's law.
Examples in business
- Pepsi vs Coca-Cola in soft drink market
- Gillette vs Schick in razor-blade market
- Airbus vs Boeing in commercial jet aircraft market
- Sotheby's vs. Christie's in diamond auctions
- Marvel Comics vs. DC Comics in comic books
- Sirius vs. XM in the satellite radio market
- Intel vs. AMD in the Microprocessor market
- The local cable company vs. the local telephone company in residential broadband Internet access
- Vodafone vs. Mobinil in the Egyptian mobile market
- Telecom vs. Vodafone in the New Zealand mobile market
- Kodak vs. Fujifilm in motion picture film stock market
- K-Kauppa vs. S-Group in the Finnish supermarket market (joinly they control 75% of supermarket market)
- Foodstuffs and Progressive Enterprises in the New Zealand supermarket market (joinly they control 90% of supermarket market)
- NVIDIA vs ATI in the mainstream Graphics card market.
Broadcasting
Duopoly is also used in the broadcast television and radio industry, referring to a single company owning two outlets in the same city. This usage is technically incompatible with the definition of the word, inasmuch as there are generally more than two owners of broadcast television stations markets with duopolies. In the United States, this has been frowned upon when using public airwaves, as it gives too much influence to one company. In Canada, this definition is more commonly called a "twinstick".
See also concentration of media ownership.
Examples in American television
- Cleveland, Ohio, USA: WOIO-CBS 19 and WUAB-MNTV 43 (Raycom Media)
- Dayton, Ohio: WKEF-ABC 22 and WRGT-Fox 45 (Sinclair Broadcast Group)
- Buffalo, New York: WIVB-CBS 4 and WNLO-The CW (LIN TV)
- Buffalo, New York: WUTV-FOX 29 and WNYO-MNTV] (Sinclair Broadcast Group)
- Raleigh, North Carolina: WRAL-CBS 5 and WRAZ-FOX 50 (Capitol Broadcasting)
- Raleigh, North Carolina: WLFL-The CW 22 and WRDC-MNTV 28 (Sinclair Broadcast Group)
- Washington, DC: WTTG-FOX 5 and WDCA-MNTV 20 (Fox Television Stations Group)
- New Orleans: WNOL-The CW 38 and WGNO ABC 26 (Tribune Broadcasting)
- Norfolk, Virginia: WAVY-NBC 10 and WVBT FOX 43 (LIN TV)
- New York, New York: WWOR-TV - MNTV 9 and WNYW - Fox 5 (Fox Television Stations Group)
- Boston, Massachusetts: WBZ-CBS 4 and WSBK- IND (CBS Corporation)
- Minneapolis-St. Paul, Minnesota: KSTP-TV-ABC 5 and KSTC-IND 45 (Hubbard Broadcasting)
- Salisbury, Maryland: WBOC-TV - CBS 16 and WBOC-TV Fox DT21.2 (Draper Holdings Business Trust)
- Denver, Colorado: KUSA-TV - NBC 9 and KTVD MNTV 20 (Gannett)
- Los Angeles, California: KCBS-TV and KCAL IND 9 (CBS Television), KNBC and KVEA (NBC Universal), and KTTV and KCOP (Fox Television Stations Group)
- Chicago, Illinois: WFLD - FOX 32 and WPWR MNTV 50 (Fox Television Stations Group)
- Little Rock, Arkansas: KLRT-TV - Fox 16 and KASN - The CW 38 (Clear Channel Communications)
There is a unique situation in Salt Lake City, where the NBC affiliate KSL-TV is owned by Bonneville International, and a PBS station, KBYU-TV, is owned by BYU. Both Bonneville and BYU are part of The Church of Jesus Christ of Latter-day Saints, and although they are on separate licenses, the fact that the ultimate owner is the LDS Church makes these stations a duopoly in a way.