🧃Intermediate Microeconomic Theory Unit 5 – Monopolistic Competition & Oligopoly

Key Concepts

• Monopolistic competition characterized by many firms selling differentiated products with low barriers to entry and exit
• Oligopoly market structure consists of a few large firms that dominate the industry and have significant market power
  • Firms in an oligopoly are interdependent their decisions affect each other's profits
• Product differentiation allows firms to charge higher prices than in perfect competition (brand loyalty, unique features)
• Non-price competition includes advertising, product quality, and customer service to attract customers in monopolistic competition
• Strategic behavior crucial in oligopolies firms must anticipate and respond to their competitors' actions
• Collusion occurs when oligopolistic firms cooperate to reduce competition and increase profits (price fixing, market sharing)
• Game theory analyzes strategic interactions among firms in oligopolies (Prisoner's Dilemma, Nash Equilibrium)
• Concentration ratios and the Herfindahl-Hirschman Index (HHI) measure market concentration in oligopolies

Market Structures Comparison

• Perfect competition characterized by many small firms, homogeneous products, and no barriers to entry or exit
  • Firms are price takers and have no market power
• Monopoly characterized by a single firm, unique product, and high barriers to entry
  • Monopolist is a price maker and has significant market power
• Monopolistic competition falls between perfect competition and monopoly
  • Many firms, differentiated products, and low barriers to entry and exit
• Oligopoly falls between monopolistic competition and monopoly
  • Few large firms, differentiated or homogeneous products, and high barriers to entry
• Perfect competition and monopolistic competition have no interdependence among firms, while oligopoly and monopoly exhibit interdependence
• Long-run economic profits are possible in monopoly and oligopoly, but not in perfect competition or monopolistic competition
• Efficiency highest in perfect competition, followed by monopolistic competition, oligopoly, and monopoly

Characteristics of Monopolistic Competition

• Large number of firms in the industry, each with a small market share
• Differentiated products that are close substitutes for each other (fast food, clothing retailers)
• Low barriers to entry and exit, allowing new firms to enter the market easily
• Firms have some control over price due to product differentiation and brand loyalty
• Demand curve is downward-sloping and more elastic than a monopolist's demand curve
• Firms engage in non-price competition to attract customers (advertising, product quality, customer service)
• In the long run, firms earn normal profits (zero economic profits) due to the threat of new entrants
• Excess capacity firms operate at a point where average total cost is not minimized

Characteristics of Oligopoly

• Few large firms dominate the industry, each with a significant market share
• Products can be differentiated (automobiles) or homogeneous (steel, oil)
• High barriers to entry, such as economies of scale, patents, or government regulations
• Firms are interdependent their decisions affect each other's profits and market shares
• Demand curve is kinked, reflecting the asymmetric response of competitors to price changes
  • Rivals match price cuts but not price increases, leading to a kinked demand curve
• Firms engage in strategic behavior, anticipating and responding to competitors' actions
• Collusion can occur, with firms cooperating to reduce competition and increase profits (cartels, price leadership)
• Non-collusive oligopoly models include Cournot, Bertrand, and Stackelberg models

Short-Run vs. Long-Run Analysis

• Short run a period where at least one input is fixed (usually capital) and firms can earn economic profits or losses
• Long run a period where all inputs are variable and firms earn normal profits (zero economic profits)
• In monopolistic competition, short-run equilibrium occurs where marginal revenue equals marginal cost (MR = MC)
  • Firms can earn positive, negative, or zero economic profits in the short run
• In the long run, the threat of new entrants drives economic profits to zero in monopolistic competition
  • Firms produce at a point where average total cost is tangent to the demand curve (P = ATC)
• In oligopoly, short-run equilibrium depends on the specific model and assumptions (Cournot, Bertrand, Stackelberg)
  • Firms can earn positive, negative, or zero economic profits in the short run
• Long-run equilibrium in oligopoly is less predictable due to the complexity of strategic interactions and potential for collusion
  • Economic profits can persist in the long run if barriers to entry remain high

Pricing Strategies

• Cost-plus pricing firms set prices by adding a markup to their average cost of production
  • Markup determined by the elasticity of demand and the firm's objectives (profit maximization, market share)
• Price discrimination charging different prices to different customers for the same product
  • Requires market segmentation, prevention of resale, and differences in price elasticity of demand
• Predatory pricing temporarily setting prices below cost to drive competitors out of the market
  • Illegal in many countries due to anti-competitive effects
• Limit pricing setting prices low enough to deter potential entrants from entering the market
  • Exploits economies of scale and the threat of post-entry price cuts
• Price leadership one firm (usually the largest or most efficient) sets the price and other firms follow
  • Can facilitate collusion and reduce competition in oligopolies
• Two-part tariffs a pricing strategy that involves a fixed fee plus a per-unit charge (amusement parks, cell phone plans)
  • Allows firms to capture more consumer surplus and increase profits

Game Theory in Oligopolies

• Game theory analyzes strategic interactions among firms in oligopolies
• Prisoner's Dilemma a classic example of how individual rationality can lead to a suboptimal outcome
  • Firms have an incentive to cheat on a collusive agreement, leading to a breakdown of cooperation
• Nash Equilibrium a situation where each firm's strategy is the best response to the strategies of its competitors
  • No firm has an incentive to unilaterally change its strategy
• Dominant strategy a strategy that yields the highest payoff for a firm, regardless of its competitors' strategies
• Cournot model firms simultaneously choose their output levels, taking their competitors' output as given
  • Equilibrium occurs where each firm's output maximizes its profits given the output of its competitors
• Bertrand model firms simultaneously choose their prices, taking their competitors' prices as given
  • Equilibrium occurs where each firm's price maximizes its profits given the prices of its competitors
• Stackelberg model a sequential game where one firm (the leader) moves first and the other firm (the follower) moves second
  • Leader anticipates the follower's reaction and incorporates it into its decision-making

Real-World Examples and Applications

• Restaurants and coffee shops are examples of monopolistic competition
  • Many firms, differentiated products, and low barriers to entry and exit
• Automobile industry is an example of an oligopoly
  • Few large firms (Toyota, GM, Volkswagen), differentiated products, and high barriers to entry
• OPEC (Organization of the Petroleum Exporting Countries) is a well-known example of a cartel in an oligopolistic market
  • Member countries collude to set oil production quotas and influence global oil prices
• Airline industry exhibits characteristics of an oligopoly
  • Few large carriers, differentiated services, and high barriers to entry (economies of scale, airport slots)
• Pharmaceutical industry is an oligopoly with significant product differentiation and high barriers to entry (patents, R&D costs)
  • Firms engage in price discrimination (different prices for different countries) and strategic behavior (patent litigation)
• Wireless telecommunications industry is an oligopoly with a few large providers (Verizon, AT&T, T-Mobile)
  • Firms compete on price, network quality, and customer service, while also engaging in mergers and acquisitions
• Game theory has been applied to analyze strategic interactions in various oligopolistic industries (airlines, pharmaceuticals, technology)
  • Helps firms make decisions regarding pricing, output, investment, and cooperation