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.
There are two principal duopoly models,
Cournot duopoly and
Bertrand duopoly:
*The
Cournot model, which shows that two firms react to one another's production (quantity) changes until they reach a
Nash equilibrium.
*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.
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.*
Pepsi vs
Coca-Cola in
soft drink 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
*
The local cable company vs.
the local telephone company in residential
broadband Internet access*
Telecom vs.
Vodafone in the
New Zealand mobile market
*
Kodak vs.
Fujifilm in
motion picture film stock market
Duopoly is also used in the broadcast television and radio industry, referring to a single company owning two outlets in the same city. 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:
WOIO-
CBS 19 and
WUAB-
UPN 43 (
Raycom Media)
*
Dayton, Ohio:
WKEF-
ABC 22 and
WRGT-
Fox 45 (
Sinclair Broadcast Group)
*
Buffalo, New York:
WIVB-
CBS 4 and
WNLO-
UPN (
LIN TV)
*
Buffalo, New York:
WUTV-
FOX 29 and
WNYO-
the WB (
Sinclair Broadcast Group)
*
Raleigh, North Carolina:
WRAL-
CBS 5 and
WRAZ-
FOX 50 (
Capitol Broadcasting)
*
Raleigh, North Carolina:
WLFL-
the WB 22 and
WRDC-
UPN 28 (
Sinclair Broadcast Group)
*
Washington, DC:
WTTG-
FOX 5 and
WDCA-
UPN 20 (
Fox Television Stations Group)
*
New Orleans:
WNOL-
WB 38 and
WGNO ABC 26 (
Tribune Broadcasting)
*
Norfolk, Virginia:
WAVY-
NBC 10 and
WVBT FOX 43 (
LIN TV)
*
New York, New York:
WWOR-TV -
UPN 9 and
WNYW -
Fox 5 (
Fox Television Stations Group)
*
Boston, Massachusetts:
WBZ-
CBS 4 and
WSBK-
UPN (
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 UPN 20 (
Gannett)
*
Los Angeles, California:
KCOP-TV -
UPN 13 and
KTTV Fox 11 (
Fox Television Stations Group)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
LDS Church, 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.
*
Monopoly*
Triopoly
