March 23, 2018 

AmosWEB means Economics with a Touch of Whimsy!

AmosWEBWEB*pediaGLOSS*aramaECON*worldCLASS*portalQUIZ*tasticPED GuideXtra CrediteTutorA*PLS
ADJUSTMENT, SHORT-RUN AGGREGATE MARKET: Disequilibrium in the short-run aggregate market induces changes in the price level that restore equilibrium. If the price level is above the short-run equilibrium price level, economy-wide product market surpluses cause the price level to fall. If the price level is below the short-run equilibrium price level, economy-wide product market shortages cause the price level to rise. In both cases short-run equilibrium is restored. You might want to compare adjustment, long-run aggregate market. Price level changes induce changes in both aggregate expenditures and real production. Unlike the long-run aggregate market, changes in the price level can induce changes in short-run aggregate supply, making it greater or less than full-employment real production.

Visit the GLOSS*arama


An oligopoly market structure containing exactly two firms. As an oligopoly, duopoly exhibits the oligopolistic characteristics and undertakes oligopolistic behavior, such as barriers to entry, interdependent actions, and nonprice competition. While duopoly, in its purest form of EXACTLY two firms in the industry, is seldom found in the real world, it does provide an excellent, easy to use illustration of oligopoly. In fact, most instructional analysis of oligopoly generally assumes a two-firm, duopoly market.
Duopoly is a special type of oligopoly market structure that contains only two firms, no more, no less. Duopoly is an ideal model for analyzing oligopoly behavior. With more than one firm, duopoly captures the essence of oligopoly, especially interdependent behavior, while keeping the analysis as simple as possible.

The duopoly model is commonly used to analyze collusion, which results when two firms join together to control the market like a monopoly. Duopoly is ideally suited for collusion analysis. It contains the minimum number of firms needed for an oligopoly and provides all of the insight that would be generated from analyzing three or more firms.

Another model using the duopoly market structure is game theory, which investigates the interdependent actions of two competing firms. Game theory is conceptually and analytically more difficult if more than two firms are included. The essential conclusion can be easily obtained using duopoly.

While the real world seldom contains a pure duopoly market structure, some industries come close. In particular, the duopoly model works well if a market is dominated by two large firms, even though it might contain other smaller ones.

One example that comes close to duopoly is the global market for passenger aircraft. This market is dominated by Boeing (from the United States) and Airbus (from Europe). The vast majority of all passenger airlines use planes manufactured by one of these two firms. Another example might be offered by a small town that contains two grocery stores.


Recommended Citation:

DUOPOLY, AmosWEB Encyclonomic WEB*pedia,, AmosWEB LLC, 2000-2018. [Accessed: March 23, 2018].

Check Out These Related Terms...

     | oligopoly, characteristics | oligopoly, behavior | oligopoly, realism | oligopoly, concentration |

Or For A Little Background...

     | oligopoly | market structures | market control | imperfect competition |

And For Further Study...

     | collusion | collusion production analysis | game theory | kinked-demand curve | kinked-demand curve analysis | cartel | concentration ratios | merger | monopoly | barriers to entry | product differentiation |

Search Again?

Back to the WEB*pedia


[What's This?]

Today, you are likely to spend a great deal of time at a crowded estate auction hoping to buy either a coffee cup commemorating last Friday (you know why) or a wall poster commemorating the first day of spring. Be on the lookout for small children selling products door-to-door.
Your Complete Scope

This isn't me! What am I?

Junk bonds are so called because they have a better than 50% chance of default, carrying a Standard & Poor's rating of CC or lower.
"It is not the straining for great things that is most effective; it is the doing of the little things, the common duties, a little better and better."

-- Elizabeth Stuart Phelps, Writer

Long Run Aggregate Supply
A PEDestrian's Guide
Xtra Credit
Tell us what you think about AmosWEB. Like what you see? Have suggestions for improvements? Let us know. Click the User Feedback link.

User Feedback

| AmosWEB | WEB*pedia | GLOSS*arama | ECON*world | CLASS*portal | QUIZ*tastic | PED Guide | Xtra Credit | eTutor | A*PLS |
| About Us | Terms of Use | Privacy Statement |

Thanks for visiting AmosWEB
Copyright ©2000-2018 AmosWEB*LLC
Send comments or questions to: WebMaster