17, Chapter Monopolistic Competition
T1 Competition with differentiated products T2 Advertising
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Monopolistic Competition describes a market with the following attributes: Many sellers: there are many firms competing for the same group of customers Product differentiation: each firm produces a product that is at least slightly different from those of other firms. Thus, rather than being a price taker, each firm faces a downward-sloping demand curve. Free entry: Firms can enter or exit the market without restriction. Thus, the number of firms in the market adjusts until economic profits are driven to zero. Markets with these attributes: books, CDs, movies, computer games, restaurants, and so on. A monopolistically competitive market departs from the perfectly competitive ideal because each of the sellers offers 2 a somewhat different product.
T1 Competition with differentiated products The monopolistically competitive firm in the short run Each firm in a monopolistically competitive market is in many ways, like a monopoly. Because its product is different from those offered by other firms, it faces a downward-sloping demand curve. Thus, the monopolistically competitive firm follows a monopolist's rule for profit maximization: it chooses the quantity at which marginal revenue equals marginal cost and then uses its demand curve to find the price consistent with that quantity. See Figure 17-1 on page 381 In panel (a), price exceeds average total cost, so the firm makes a profit. In panel (b), price is below average total cost. In this case, the firm is unable to make a positive 3 profit, so the best the firm can do is to minimize its losses.
The long run equilibrium The situation depicted in Figure 17-1 do not last long. When firms are making profits,as in panel(a), new firms have an incentive to enter the market. This entry increases the number of products from which customers can choose and therefore, reduces the demand faced by each firm already in the market. In other words, profit encourages entry, and entry shifts the demand curves faced by the incumbent firms to the left. As the demand for incumbent firms' products falls, these firms experience declining profit. Conversely, when firms are making losses, as in panel (b), firms in the market have an incentive to exit. As firm exit,customers have fewer products from which to choose. 4 This decrease in the number of firms, expands the
demand faced by those incumbent firms. In other words, losses encourage exit, and exit shifts the demand curves of the remaining firms to the right. As the demand for the remaining firms' products rises, these firms experience rising profit ( that is declining losses). This process of entry and exit continues until the firms in the market are making exactly zero economic profit. See Figure 17-2 on page 383. Once the market reaches this equilibrium, new firms have no incentive to enter and existing firms have no incentive to exit. Notice that the demand curve and the average total cost curve are tangent to each other. These two curves must be tangent once entry and exit have driven profit to zero. Because profit per unit sold is the difference between price 5 and average total cost, the maximum profit is zero
only if these two curves touch each other without crossing. To sum up, two characteristics describe the long-run equilibrium in a monopolistically competitive market: Price exceeds marginal cost (same as in a monopoly market). This conclusion arises because profit maximization requires marginal revenue to equal marginal cost and because the downward-sloping demand curve makes marginal revenue less than the price. Price equals average total cost (same as in a competitive market). This conclusion arise because free entry and exit drive economic profit to zero. The second characteristic shows how monopolistic competition differs from monopoly. Monopoly can earn positive economic profit even in the long run because it is the sole seller of a product without close substitutes. 6
By contrast, because there is a free entry into a monopolistically competitive market, the economic profit of a firm in this type of market is driven to zero. Monopolistic Vs perfect competition See Figure 17-3 on page 384 There are two noteworthy differences between monopolistic and perfect competition: excess capacity and the markup. The perfectly competitive firm produces at the efficient scale, where average total cost is minimized. By contrast, the monopolistically competitive firm produces at less than the efficient scale. Firms are said to have excess capacity under monopolistic competition. Price equals marginal cost under perfect competition, but price is above marginal cost under monopolistic competition.
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How is this markup over marginal cost consistent with free entry and zero profit? The zero-profit condition ensures only that price equals average total cost. It does not ensure that price equals marginal cost. Indeed, in the long-run equilibrium, monopolistically competitive firms operate on the declining portion of their average-total-cost curves, so marginal cost is below average total cost. Thus, for price to equal average total cost, price must be above marginal cost. A key behavioural difference between perfect competitors and monopolistic competitors: A monopolistically competitive firm is always eager to get another customer. Because its price exceeds marginal cost, 8 an extra unit sold at the posted price means more profit.
By contrast, a perfectly competitive firm doesn't care to get another customer. Because price exactly equals marginal cost, the profit form an extra unit sold is zero. Monopolistic competition and the welfare of society Questions: Is the outcome in a monopolistically competitive market desirable from the stand point of society as a whole? Can policymakers improve on the market outcome? There are no simple answers to these questions. One source of inefficiency is the markup of price over marginal cost. Because of the markup, some consumers who value the good at more than the marginal cost of production (but less than the price) will be deterred from buying it. Thus, a monopolistically competitive market has the normal 9 deadweight loss of monopoly pricing.
Although this outcome is clearly undesirable compared with the first-best outcome of price equal to marginal cost, there is no easy way for policymakers to fix the problem. To enforce marginal-cost pricing, policymakers would need to regulate all firms that produce differentiated products. Because such products are so common in the economy, the administrative burden of such regulation would be overwhelming. Besides, because monopolistic competitors are making zero profits already, requiring them to lower their prices to equal marginal cost would cause them to make losses. To keep these firms in business, the government would need to help them cover these losses. Rather than raising taxes to pay for these subsidies, policymakers may decide it is better to live with the inefficiency of monopolistic pricing. 10
Another way in which monopolistic competition may be socially inefficient is that the number of in firms the market may not be the "ideal" one. That is, there may be too much or too little entry. To think about this problem in term of the externalities associated with entry: Whenever a new firm considers entering the market with a new product, it considers only the profit it would make. Yet its entry would also have two external effects: The product-variety externality: Because consumers get some consumer surplus from the introduction of a new product, entry of a new firm conveys a positive externality on consumers. The business-stealing externality: Because other firms lose customers and profits from the entry of a new competitor, entry of a new firm imposes a negative 11 externality on existing firms.
Depending on which externality is larger, a monopolistically competitive market could have either too few or too many products. The product-variety externality arises because a new firm would offer a product different from those of the existing firms. The business-stealing externality arises because firms post a price above marginal cost and therefore, are always eager to sell additional units. Conversely, because perfectly competitive firms produce identical goods and charge a price equal to marginal cost, neither of these externality exists under perfect competition. We can conclude that monopolistically competitive markets do not have all desirable welfare properties of perfectly competitive markets. 12
That is, the invisible hand (market) does not ensure that total surplus is maximized under monopolistically competition. Yet, because the inefficiencies are subtle, hard to measure and hard to fix, there is no easy way for public policy to improve the market outcome. T2 Advertising When firms sell differentiated products and charge prices above marginal cost, each firm has an incentive to advertise in order to attract more buyers to its particular product. The amount of advertising varies substantially across products. Highly differentiated consumer goods (such as perfumes, soft drinks, razor blades, breakfast cereals, and dog food) : 10% to 20% of revenue for advertising. Industrial products ( such as drill presses and 13 communications satellites): very little on advertising.
Homogeneous products (such as wheat, peanuts or crude oil): spend nothing at all. The debate over advertising Question: Is society wasting the resources it devotes to advertising? Or does advertising serve a valuable purpose? Let's consider both sides of the debate. The Critique of advertising: 1, Firms advertise in order to manipulate people's tastes. Much advertising is psychological rather than informational. Such a commercial creates a desire that otherwise might not exist. 2, Advertising impedes competition. Advertising often tries to convince consumers that products are more different than they truly are. By increasing the perception of product differentiation and fostering brand loyalty, advertising 14 makes buyers less concerned with price differences among
similar goods. With a less elastic demand curve, each firm charges a larger markup over marginal cost. The Defence of advertising: 1, Firms use advertising to provide information to customers. Advertising conveys the prices of the goods being offered for sale, the existence of new products and the locations of retail outlets. This information allows customers to make better choices about what to buy and thus, enhances the ability of markets to allocate resources efficiently. 2, Advertising fosters competition. Because advertising allows customers to be more fully informed about all the firms in the market, customers can more easily take advantage of price differences. Thus, each firm has less market power. In addition, advertising allows new firms to enter more easily because it gives entrants a means to attract 15 customers from existing firms.
Case study: advertising and the price of eyeglasses What effect does advertising have on the price of a good? On the one hand, advertising might make consumers view products as being more different than they otherwise would. If so, it would make markets less competitive and firms' demand curves less elastic and this would lead firms to charge higher prices. On the other hand, advertising might make it easier for consumers to find the firm...