📈Business Microeconomics Unit 7 – Market Structures: Monopoly to Oligopoly

Key Concepts and Definitions

• Market structures categorize industries based on the number of firms, degree of product differentiation, and barriers to entry
• Perfect competition consists of many small firms selling identical products with no barriers to entry or exit
• Monopolistic competition includes many firms selling differentiated products with low barriers to entry
• Oligopoly is characterized by a few large firms dominating the market with high barriers to entry
  • Firms in an oligopoly are interdependent and consider each other's actions when making decisions
• Monopoly is a single firm that controls the entire market for a good or service with significant barriers to entry
• Market power refers to a firm's ability to influence the price and quantity of a good or service in the market
• Allocative efficiency occurs when the price of a good equals its marginal cost of production
• Productive efficiency is achieved when a firm produces a given level of output at the lowest possible cost

Types of Market Structures

• Perfect competition, monopolistic competition, oligopoly, and monopoly are the four main types of market structures
• In perfect competition, firms are price takers and have no market power (agricultural markets)
• Monopolistic competition involves product differentiation and some degree of market power (restaurants, clothing retailers)
• Oligopolies have a small number of firms with substantial market power and strategic interactions (airlines, telecommunications)
  • Oligopolies can engage in price leadership, where one firm sets the price and others follow
• Pure monopoly is characterized by a single firm with complete market control and high barriers to entry (public utilities)
• The degree of market power increases from perfect competition to monopolistic competition, oligopoly, and monopoly
• Market concentration measures, such as the Herfindahl-Hirschman Index (HHI), quantify the level of competition within a market
• The structure of a market influences firm behavior, pricing decisions, and overall market efficiency

Characteristics of Monopolies

• A monopoly is a single seller of a unique product with no close substitutes
• Significant barriers to entry prevent new firms from entering the market (legal restrictions, economies of scale, control over essential resources)
• Monopolies are price makers and can influence the market price by adjusting output levels
  • They face a downward-sloping demand curve, as they must lower prices to sell more units
• Monopolies have market power and can engage in price discrimination to maximize profits
• Natural monopolies arise when a single firm can supply the market at a lower cost than multiple firms (utilities, railways)
• Government-created monopolies are established through legal barriers, such as patents or exclusive licenses
• Monopolies may lack incentives to innovate or improve efficiency due to the absence of competitive pressures
• The social costs of monopolies include higher prices, reduced output, and deadweight loss compared to competitive markets

Monopoly Pricing and Output Decisions

• Monopolies aim to maximize profits by setting marginal revenue (MR) equal to marginal cost (MC)
• The profit-maximizing quantity occurs where $MR = MC$, and the price is determined by the demand curve at that quantity
• Monopolies produce less output and charge higher prices compared to perfectly competitive firms
  • This leads to allocative inefficiency and deadweight loss
• Monopolies can engage in price discrimination by charging different prices to different consumers based on their willingness to pay
  • First-degree price discrimination charges each consumer their maximum willingness to pay
  • Second-degree price discrimination offers different prices based on quantity purchased (volume discounts)
  • Third-degree price discrimination separates consumers into distinct groups and charges each group a different price (student discounts)
• Price discrimination allows monopolies to capture more consumer surplus and increase profits
• Monopolies have no supply curve, as they do not have a unique price-quantity relationship
• The absence of competitive pressures may lead to X-inefficiency, where monopolies fail to minimize costs

Oligopoly Models and Strategies

• Oligopoly models include the Cournot model, Bertrand model, and Stackelberg model
• The Cournot model assumes that firms choose their output levels simultaneously, taking their competitors' output as given
  • Firms reach a Nash equilibrium where each firm's output is the best response to the others' output
• The Bertrand model assumes that firms compete on price, taking their competitors' prices as given
  • This leads to a Nash equilibrium where prices equal marginal costs, similar to perfect competition
• The Stackelberg model is a sequential game where one firm (the leader) chooses its output first, and the other firm (the follower) responds
  • The leader has a first-mover advantage and can anticipate the follower's reaction
• Oligopolies may engage in collusive behavior to maximize joint profits, such as forming cartels or agreeing on price fixing
  • Collusion is illegal in most countries and can lead to antitrust action
• Non-collusive oligopoly strategies include price leadership, where one firm sets the price and others follow
• Game theory is used to analyze oligopoly behavior and the strategic interactions among firms
• The kinked demand curve model explains price rigidity in oligopolies, as firms are reluctant to change prices due to the anticipated reactions of competitors

Market Power and Efficiency

• Market power refers to a firm's ability to set prices above marginal costs and earn economic profits
• The degree of market power depends on the market structure, with monopolies having the most power and perfectly competitive firms having none
• Market power leads to allocative inefficiency, as prices exceed marginal costs, and the quantity produced is less than the socially optimal level
  • This results in deadweight loss, which is a net loss of social welfare
• Productive inefficiency may also occur when firms with market power lack incentives to minimize costs
• The Lerner Index measures the degree of market power by calculating the markup of price over marginal cost as a percentage of price
  • $Lerner Index = \frac{P - MC}{P}$
• A higher Lerner Index indicates greater market power and a larger deviation from the competitive outcome
• The Herfindahl-Hirschman Index (HHI) measures market concentration by summing the squared market shares of all firms in the industry
  • $HHI = \sum_{i=1}^{N} s_i^2$, where $s_i$ is the market share of firm $i$
• A higher HHI indicates a more concentrated market and potentially greater market power
• Market power can lead to dynamic inefficiency, as firms may have reduced incentives to invest in research and development or innovate

Regulation and Antitrust Policies

• Governments use regulation and antitrust policies to address the inefficiencies and social costs associated with market power
• Regulation involves setting rules and standards for firm behavior, such as price controls, quality requirements, or entry restrictions
  • Natural monopolies (utilities) are often regulated to prevent excessive pricing and ensure fair access
• Antitrust policies aim to promote competition and prevent the abuse of market power
  • The Sherman Act (1890) prohibits monopolization and restraints of trade, such as price fixing and market allocation
  • The Clayton Act (1914) addresses mergers and acquisitions that may substantially lessen competition
  • The Federal Trade Commission Act (1914) established the FTC to investigate and prevent unfair methods of competition
• Antitrust authorities (DOJ, FTC) review mergers and acquisitions to assess their impact on market competition
  • Horizontal mergers between competitors are more likely to raise antitrust concerns than vertical mergers between suppliers and customers
• Antitrust enforcement actions include blocking mergers, breaking up firms, and imposing fines for anticompetitive behavior
• Regulatory capture occurs when regulatory agencies are influenced by the industries they are meant to regulate, potentially leading to policies that benefit firms rather than consumers
• The goal of regulation and antitrust policies is to balance the benefits of market power (economies of scale, innovation incentives) with the costs (allocative and productive inefficiencies)

Real-World Examples and Case Studies

• Microsoft's dominance in the operating system market (Windows) and web browser market (Internet Explorer) led to antitrust cases in the US and EU
  • Microsoft was accused of leveraging its monopoly power to exclude competitors and limit consumer choice
• The breakup of AT&T's telephone monopoly in 1984 aimed to promote competition in the telecommunications industry
  • The breakup resulted in the creation of regional Bell operating companies and opened the market to new entrants
• The merger between AT&T and Time Warner in 2018 faced antitrust scrutiny due to concerns about the concentration of market power in the media and telecommunications industries
  • The merger was eventually approved with conditions to ensure fair access to content for competitors
• The OPEC (Organization of the Petroleum Exporting Countries) cartel has significant market power in the global oil market
  • OPEC countries coordinate production levels to influence oil prices and maximize joint profits
• The pharmaceutical industry often exhibits monopoly power due to patent protection and high barriers to entry
  • Drug companies can charge high prices for patented drugs, leading to concerns about affordability and access
• The airline industry is an example of an oligopoly, with a few large carriers dominating the market
  • Airlines engage in price discrimination (business vs. economy class) and strategic behavior (loyalty programs, capacity management)
• The tech giants (Google, Amazon, Facebook, Apple) have faced antitrust investigations and calls for regulation due to their market dominance and potential anticompetitive practices
  • Concerns include the acquisition of potential competitors, self-preferencing of own products, and the use of data to limit competition