when at least one condition of a perfect market is not met it can lead to an imperfect market every industry has some form of imperfection imperfect competition can be found in the following structures 
this is a structure in which there is only one dominant seller products offered by this entity have no substitutes these markets have high barriers to entry and a single seller who sets the prices on goods and services prices can change without notice to consumers this structure has many buyers but few sellers these few players in the market may bar others from entering they may set prices together or in the case of a cartel only one takes the lead to determine the price for goods and services while the others follow in monopolistic competition there are many sellers who offer similar products that can t be substituted businesses compete with one another and are price makers but their individual decisions do not affect the other these structures have many sellers but few buyers in both cases the buyer is the one who manipulates market prices by playing firms against one another imperfect markets vs perfect marketsperfect markets are characterized by having the following in reality no market can ever have an unlimited number of buyers and sellers economic goods in every market are heterogeneous not homogeneous as long as more than one producer exists a diverse range of goods and tastes are preferred in an imperfect market perfect markets though impossible to achieve are useful because they help us think through the logic of prices and economic incentives it is a mistake however to try extrapolating the rules of perfect competition into a real world scenario logical problems arise from the start especially the fact that it is impossible for any purely competitive industry to conceivably attain a state of equilibrium from any other position perfect competition can thus only be theoretically assumed it can never be dynamically reached 