ECO 204 Week 4 DQ 1 Market Structures Market Structures. Explain the most important characteristic in perfect competition, monopolistic competition, oligopoly, and monopolies and relate the characteristic to how these firms can make profits in the short run. In your analysis, make sure to relate an example for each of the market structures listed and how it relates to the particular characteristics. Guided Response: Review the discussion board posts of your classmates. Analyze the difference between market structures. Compare your response to those of your classmates. Respond to at least two of your classmates. Discuss the way profits vary based on market structure.