The kinked demand curve is a model used to explain price stability in an oligopoly, characterized by a demand curve that has a distinct 'kink' at the current market price. This kink occurs because firms expect that if they raise prices, their competitors will not follow suit, leading to a loss of market share, but if they lower prices, competitors will match the price drop, reducing their revenues. This results in a unique situation where prices tend to remain stable despite changes in costs or demand, as firms are reluctant to change their prices due to the potential reactions from rivals.