Unit 3: Market Structures - Subjective Questions

Perfect competition is a market structure in which a large number of buyers and sellers trade a homogeneous product, and no individual firm can influence the market price. Each firm is a price taker.

Main features:

• Large number of buyers and sellers: Each buyer and seller represents an insignificant portion of total market demand or supply.
• Homogeneous product: All firms sell identical products, so buyers have no preference among sellers.
• Free entry and exit: Firms can enter or leave the industry without significant restrictions.
• Perfect knowledge: Buyers and sellers have complete information about prices, quality, and market conditions.
• Perfect mobility of factors: Resources can move freely from one occupation or industry to another.
• Uniform market price: A firm must accept the price determined by industry demand and supply.
• No selling costs: Advertising and other promotional expenses are unnecessary because products are identical.

Thus, perfect competition provides the theoretical benchmark for understanding price and output determination.

A perfectly competitive firm is called a price taker because it cannot influence the market price. The industry price is determined by the interaction of total market demand and total market supply. Since each firm supplies only a small part of the total output, changing its own output does not affect the market price.

At the prevailing price, the firm can sell any quantity within its capacity. Therefore:

• Price = Average Revenue:
• Price = Marginal Revenue:
• Consequently,

The firm's demand curve is perfectly elastic and is represented by a horizontal line parallel to the quantity axis. This means that the firm can sell additional units at the same market price, but it cannot charge a higher price because buyers would purchase from other firms.

Under perfect competition, the industry determines the market price through the interaction of market demand and market supply.

• The market demand curve slopes downward because consumers generally demand more at lower prices.
• The market supply curve slopes upward because producers are generally willing to supply more at higher prices.
• The equilibrium price is determined at the point where market demand equals market supply.

The equilibrium condition is:

At the equilibrium point, the market determines both the price and the total quantity bought and sold. If the price is above equilibrium, supply exceeds demand and a surplus appears, causing price to fall. If the price is below equilibrium, demand exceeds supply and a shortage appears, causing price to rise.

Thus, the industry is a price maker, while individual firms accept the price and adjust their output accordingly.

A perfectly competitive firm maximizes profit by producing the output level at which the difference between total revenue and total cost is greatest. The necessary equilibrium condition is:

Since the firm is a price taker, . Therefore, the equilibrium condition can also be written as:

For equilibrium to be stable, the marginal cost curve must cut the marginal revenue curve from below. In other words:

• Before equilibrium output, , so producing additional units increases profit.
• At equilibrium output, .
• After equilibrium output, , so producing additional units reduces profit.

The firm may earn supernormal profit, normal profit, or incur a loss in the short run. It will continue production as long as price covers average variable cost:

If , the firm minimizes its loss by temporarily shutting down.

The short-run supply curve of a perfectly competitive firm shows the quantities the firm is willing to supply at different prices, assuming that some factors of production remain fixed.

The firm produces where:

However, the firm will supply output only when the price covers its average variable cost. Therefore, the short-run supply curve is the portion of the short-run marginal cost curve that lies above the minimum point of the average variable cost curve.

Reasons:

• If , the firm covers all variable costs and contributes something toward fixed costs.
• If , the firm is at its shutdown point.
• If , continuing production increases losses, so the firm shuts down.

Thus, the rising part of the marginal cost curve above the shutdown point represents the firm's short-run supply curve.

In the long run, all factors of production are variable, and firms can freely enter or leave the industry. Long-run equilibrium requires both firm-level and industry-level adjustment.

A firm is in long-run equilibrium when:

The equality of price and marginal cost ensures efficient output, while the equality of price and average cost means that the firm earns only normal profit.

Adjustment process:

• If firms earn supernormal profits, new firms enter the industry.
• Entry increases industry supply, causing the market price to fall.
• If firms incur losses, some firms leave the industry.
• Exit decreases industry supply, causing the market price to rise.
• Entry or exit continues until firms earn normal profit.

Therefore, in long-run competitive equilibrium, firms produce at the minimum point of their long-run average cost curve and resources are allocated efficiently.

Monopoly is a market structure in which a single seller controls the entire supply of a product or service that has no close substitute. The monopolist is the sole producer and has considerable control over price.

Main features:

• Single seller: One firm constitutes the entire industry.
• No close substitutes: Consumers cannot easily switch to an alternative product.
• Strong barriers to entry: Legal, financial, technological, or strategic barriers prevent new firms from entering.
• Price maker: The monopolist can influence price by changing the quantity supplied.
• Downward-sloping demand curve: The firm's demand curve is the market demand curve.
• Possibility of price discrimination: The monopolist may charge different prices to different consumers or markets.
• Restricted competition: Since there is only one seller, direct competition is absent.

Although the monopolist controls supply, it cannot freely set both price and quantity because consumers' demand limits its choices.

Under monopoly, the firm's average revenue curve is the same as its demand curve because the monopolist is the only seller in the market.

The demand curve slopes downward, which means that the monopolist must reduce price to sell a larger quantity. As a result, marginal revenue is less than average revenue for every output level beyond the first unit.

The marginal revenue curve lies below the average revenue curve and declines more rapidly. If the demand function is linear, the marginal revenue curve has the same vertical intercept as the demand curve but twice its slope.

For example, if:

then total revenue is:

and marginal revenue is:

This relationship is important because the monopolist determines output where marginal revenue equals marginal cost and then charges the price indicated by the demand curve.

A monopolist maximizes profit by producing the output at which marginal revenue equals marginal cost:

The equilibrium output is determined at the point where the marginal revenue curve intersects the marginal cost curve, with marginal cost rising through the marginal revenue curve. After determining the equilibrium quantity, the monopolist moves vertically upward to the demand or average revenue curve to find the corresponding price.

The process is as follows:

• Determine the output where .
• Identify the price consumers are willing to pay for that quantity from the demand curve.
• Compare price with average cost to determine the level of profit or loss.

Profit is:

A monopolist may earn supernormal profit in the short run or long run because entry barriers prevent competitors from entering. Unlike a perfectly competitive firm, the monopolist generally charges a price greater than marginal cost:

A monopolist does not have a definite supply curve because there is no unique relationship between price and quantity supplied under monopoly.

Under perfect competition, a firm's supply curve shows the quantity supplied at each possible price, usually based on the marginal cost curve. Under monopoly, however, the quantity and price are determined jointly by the interaction of demand and marginal cost.

Reasons:

• The monopolist faces a downward-sloping demand curve.
• A change in demand can alter both equilibrium price and equilibrium quantity.
• The same price may be associated with different quantities under different demand conditions.
• The same quantity may be sold at different prices if the demand curve changes.

The monopolist first chooses output where:

and then determines price from the demand curve. Since the demand curve is essential to the decision, marginal cost alone cannot determine a supply relationship. Therefore, monopoly has no unique supply curve.

Price discrimination occurs when a monopolist charges different prices for the same product or service to different buyers or markets, and the price differences are not based on differences in production cost.

Main types:

• First-degree price discrimination: The seller charges each consumer the maximum price that consumer is willing to pay. The entire consumer surplus is appropriated by the seller.
• Second-degree price discrimination: The price varies according to the quantity purchased or the version of the product. Examples include quantity discounts and electricity pricing slabs.
• Third-degree price discrimination: Different prices are charged in separate markets or to different groups of consumers, such as student discounts or different domestic and foreign prices.

Price discrimination is possible when:

• The seller has market power.
• Markets can be separated.
• Resale between buyers is difficult or impossible.
• Consumers have different price elasticities of demand.

A monopolist generally charges a higher price in the market with less elastic demand.

Monopolistic competition is a market structure in which many firms sell products that are close substitutes but differentiated by brand, quality, design, location, packaging, or service.

Main features:

• Large number of firms: Each firm has a relatively small share of the market.
• Product differentiation: Products are similar but not identical.
• Free or relatively free entry and exit: Firms can enter or leave the industry in the long run.
• Some control over price: Product differentiation gives each firm limited monopoly power.
• Downward-sloping demand curve: A firm can sell more by lowering its price, although it faces competition from close substitutes.
• Selling costs: Advertising, branding, and sales promotion are important.
• Non-price competition: Firms compete through quality, design, packaging, customer service, and advertising.

Monopolistic competition combines elements of both monopoly and competition: firms have differentiated products and some price control, but many competitors limit their market power.

Product differentiation means creating differences between a firm's product and those of competing firms. The differences may be real or perceived.

Forms of differentiation include:

• Differences in quality and design.
• Differences in packaging and appearance.
• Brand names and trademarks.
• Location and convenience.
• Customer service and warranties.

Selling costs are expenses incurred to increase demand for a product or to persuade consumers to prefer one brand over another. They include:

• Advertising expenses.
• Sales promotions and discounts.
• Product demonstrations.
• Distribution and display costs.
• Brand-building activities.

Product differentiation gives a firm a downward-sloping demand curve and limited monopoly power. Selling costs may shift the firm's demand curve to the right or make it less elastic. However, excessive advertising may increase total costs and reduce profit. Therefore, firms compare the additional revenue from promotion with its additional cost.

In the short run, a firm under monopolistic competition behaves like a monopolist because its differentiated product gives it some control over price. It faces a downward-sloping average revenue or demand curve and a marginal revenue curve below it.

The firm determines equilibrium output where:

After finding the equilibrium output, the firm determines price from the demand curve. The firm's profit is calculated as:

Depending on the relationship between price and average cost, the firm may experience:

• Supernormal profit:
• Normal profit:
• Loss:

The firm will continue operating in the short run if price covers average variable cost:

Thus, short-run equilibrium resembles monopoly equilibrium, but the presence of close substitutes limits the firm's pricing power.

In the long run, firms can enter or leave a monopolistically competitive industry. If existing firms earn supernormal profits, new firms enter with competing products. This reduces the demand faced by each existing firm. Entry continues until only normal profit remains.

Long-run equilibrium occurs when:

and the demand curve is tangent to the average cost curve. At equilibrium:

However, the firm does not generally produce at the minimum point of its average cost curve. It produces at an output below the minimum-cost output because its demand curve slopes downward.

This unused productive capacity is called excess capacity. It is represented by the difference between the output produced in long-run equilibrium and the output at which average cost is minimum.

Monopolistic competition therefore provides product variety but does not achieve the productive efficiency of perfect competition.

The three market structures differ in the number of firms, nature of products, control over price, and entry conditions.

Perfect competition emphasizes competition and uniform products, monopoly emphasizes sole control and barriers to entry, while monopolistic competition combines competition among many firms with product differentiation.

Oligopoly is a market structure in which a small number of large firms dominate the supply of a product or service. Each firm's decisions affect the other firms, so firms are mutually interdependent.

Main features:

• Few sellers: A small number of firms control a large share of the market.
• Interdependence: Each firm considers the likely reactions of rivals before changing price, output, or advertising.
• Barriers to entry: High capital requirements, economies of scale, patents, control over resources, and brand loyalty may prevent entry.
• Homogeneous or differentiated products: Products may be standardized, such as steel, or differentiated, such as automobiles.
• Importance of non-price competition: Firms often compete through advertising, product innovation, warranties, and service rather than price cuts.
• Possibility of collusion: Firms may cooperate to fix prices or divide markets.
• Uncertainty: There is no single general theory of oligopoly because firms may behave competitively, cooperatively, or strategically.

The defining characteristic of oligopoly is strategic interdependence among a few powerful firms.

Pure oligopoly and differentiated oligopoly are two forms of oligopoly based on the nature of the product.

Pure oligopoly:

• Firms sell homogeneous or standardized products.
• Products are almost identical in quality and use.
• Competition is often based on price, cost efficiency, and production capacity.
• Examples include markets for steel, cement, aluminum, and certain raw materials.

Differentiated oligopoly:

• Firms sell products that are similar but distinguished by brand, design, quality, features, or service.
• Firms use advertising, innovation, and branding to build customer loyalty.
• Competition is often non-price competition.
• Examples include automobiles, smartphones, airlines, and soft drinks.

In both forms, the number of firms is small, entry barriers are significant, and firms are mutually interdependent. The major difference is whether the products are standardized or differentiated.

In an oligopoly, each firm is large enough to influence the market. Consequently, a firm's decisions affect the sales, profits, and strategies of its rivals. This condition is called interdependence.

Before changing price or output, a firm considers:

• How competitors may respond.
• Whether rivals will match a price reduction.
• Whether rivals will reduce their own prices.
• The likely effect on market share and profit.
• Possible responses to advertising, product changes, or entry into a new market.

This makes oligopolistic behavior strategic. Firms may adopt either cooperative or non-cooperative strategies.

• Cooperative behavior: Firms may form a cartel, agree on prices, restrict output, or divide markets.
• Non-cooperative behavior: Firms independently choose strategies while anticipating rival reactions.

Because different assumptions about rival behavior lead to different outcomes, there is no single universal model of oligopoly. Game theory is often used to study these strategic decisions.

The kinked demand curve theory explains why prices in oligopolistic markets may remain stable even when costs change moderately. It assumes that rival firms behave asymmetrically toward a price change.

• If one firm raises its price, rivals may not follow. The firm then loses many customers, so the demand curve above the current price is relatively elastic.
• If one firm lowers its price, rivals may follow to protect their market shares. The firm gains very few additional customers, so the demand curve below the current price is relatively inelastic.

These two segments meet at the prevailing price and quantity, creating a kink. The corresponding marginal revenue curve has a discontinuous gap.

If the marginal cost curve shifts within this gap, the profit-maximizing output and price remain unchanged. This explains price rigidity or the tendency of oligopolistic firms to avoid frequent price changes.

The theory explains price stability but does not explain how the initial price is determined.