10.7 : 垄断竞争、完全竞争与垄断

Perfect competition, monopolistic competition, and monopoly have unique characteristics shaping how goods and services are bought and sold.

All three market structures aim to maximize profits, and firms achieve this by producing at the quantity where marginal cost equals marginal revenue. Also, in the long run, firms in perfect and monopolistic competition earn normal profits, while monopolists can earn economic profits.

Perfect competition has a large number of buyers and sellers selling identical products. The monopolistic competition features numerous firms that produce differentiated products. Monopoly has a single dominating firm offering unique products without close substitutes.

The demand curve is a horizontal line in perfect competition, while others face a downward-sloping demand curve.

In perfect competition, firms can freely enter and exit the market. In monopolistic competition, entry is relatively free but faces some minor restrictions. However, significant barriers to entry exist in a monopoly.

Perfectly competitive firms are price takers, monopolistic competitors have some control over prices, and in monopolies, firms are price setters.

Despite some similarities, these market structures differ significantly.