If we assume that all firms in a perfectly competitive constant cost industry are identical, we conclude that, in the long run, product price will exactly equal the firms' minimum average total cost. Explain why this is true using supply and demand curves. For example, say that demand for a product falls due to changing consumer tastes, while the cost curves of the firms are unchanged. Describe what happens using supply and demand curves. In the long run, does the market price change due to the shift in the demand curve? Why or why not?