Define the general concept of market structure and analyze the four primary market models identified in this course. Select a specific industry or industries that characterize each model and elaborate on the characteristics and performance of each in demonstrating the qualities representative of their respective markets. ( Some examples of distinguishing characteristics may include, number of firms in the industry, existence of industry leadership and percent of market share distribution ). 4 market models – Monopolistic competition, monopoly, perfect competition, and oligopoly. Website sources preferred. A minimum of 3 sources required.