Choose an industry that you think might be a perfectly competitive industry. If firms in this industry have positive economic profits, what would you expect to happen in the industry (use the perfectly competitive model (graph analysis) to explain). What do you expect to happen in this industry in the short-run? In the long-run? What does it mean for a firm to have "normal profits"? If this firm has normal profits, what changes could they make to shift their MC and ATC curves downwards and have profits again. If they make these changes, what will happen next in this industry?