Differences between pure competition and pure monopoly can be easily seen in the graphs. Construct the demand and marginal revenue curves for a purely competitive firm and a pure monopolist. Not only will we see that the demand curves are different (perfectly elastic versus downward sloping), we will also notice the difference in the marginal revenue curves. Draw a marginal cost curve in both graphs. In the absence of average cost curves, find the profit-maximizing output and price in each graph. Note the analogy between P = MC in pure competition (where MR = P) and MC = MR for a pure monopoly. Comment.