Market Power and Monopoly Study Notes
Market Power and Monopoly
Introduction
In reality, perfectly competitive industries are rare.
Firms typically possess market power, defined as the ability to influence the market price of a product.
Monopoly is the extreme case of market power, where a single firm is the only supplier in the market.
A monopolist is defined as the sole supplier and price setter of a good in a market, impacting their pricing behavior.
9.1 Sources of Market Power
The primary differentiator between perfect competition and other market structures is the barriers to entry.
Barriers to entry are factors preventing other firms from entering the market and affecting pricing and profits.
In a typical competitive market, the positive producer surplus induces new firms to enter until it is reduced to zero.
Barriers to entry allow existing firms to maintain positive producer surplus indefinitely.
Extreme Scale Economies: Natural Monopoly
Economies of scale lead to a situation where it is most efficient for one firm to produce the entire industry output.
This is reflected in a downward sloping long-run average total cost curve, indicating that diseconomies of scale never arise.
Natural monopoly refers to this phenomenon.
Illustrative example:
Consider a total cost structure $TC = 100 + 10Q$; this leads to the average total cost $ATC = rac{100}{Q} + 10$.
Switching Costs
Switching costs pose a barrier, driven by:
Brand-related opportunity costs (e.g., benefits from loyalty programs).
Technical constraints (e.g., incompatibility between operating systems).
Search costs (e.g., comparing multiple health insurance plans).
Network goods: the value of a good increases as more consumers use it.
Examples include:
Telecommunications.
Computer operating systems.
Product Differentiation
In many non-commodity markets, products are not seen as perfect substitutes.
For instance, Burger King and Chipotle compete in the fast-food sector but offer significantly different products.
Product differentiation refers to the imperfection in substitutability of different varieties of a product.
Absolute Cost Advantages or Control of Key Inputs
Some firms can secure a competitive edge via scarce inputs, e.g., a particular natural resource.
Example: Saudi Aramco, controlling vast quantities of oil, enjoys lower extraction costs.
Firms can also create absolute cost advantages via long-term contracts with suppliers, as seen with Apple's relationship with Foxconn.
Government Regulation
Effective barriers may also arise from government impositions limiting market entry.
Examples include:
Patents.
Licensing requirements (e.g., medical board certifications).
Prohibition of competition (e.g., U.S. Postal Service).
9.2 Market Power and Marginal Revenue
Demand Curve Characteristics
A monopolist encounters the market demand curve directly, with no competition.
Price is variable; the only way to sell more is by lowering the price.
In contrast, perfectly competitive firms can sell any quantity at market price.
Other market structures where firms face downward-sloping demand include:
Oligopoly (e.g., automobile industry) - a few firms operate with strategic behavior.
Monopolistic competition (e.g., fast food) - many firms sell differentiated products.
Marginal Revenue Under Market Power
In perfect competition, the demand curve is horizontal; thus, marginal revenue equals price.
For firms with market power, the demand curve is downward sloping, leading to a downward sloping marginal revenue curve.
Example: Durkee-Mower, Inc., producing Marshmallow Fluff, has held a dominant market position since the 1920s.
Marginal Revenue Table
Table 9.1 illustrates how price and marginal revenue relate to the quantity produced of Marshmallow Fluff.
Quantity (millions of pounds)
Price ($/pound)
Total Revenue ($ millions)
Marginal Revenue ($ millions)
0
6
0
0
1
5
5
5
2
4
8
3
3
3
9
1
4
2
8
-1
Explanation of Marginal Revenue
The marginal revenue does not equate to price due to the downward sloping demand curve.
When the firm produces more:
The price for all products decreases since a fixed market price applies.
Price discrimination: a strategy where firms charge different prices based on customer willingness to pay.
Mathematical Breakdown of Marginal Revenue
Marginal revenue breakdown:
Increased total revenue from higher sales.
Decreased total revenue due to the drop in price for all previously sold units.
Marginal Revenue Equation
The combined effects can be mathematically expressed as:
MR = P + rac{dP}{dQ} imes Q
Linear Demand Curve Effects
Linear demand curve:
P = a - bQ
Then, the marginal revenue is given by:
MR = a - 2bQ
9.3 Profit Maximization for a Firm with Market Power
Producing Decisions and Market Output
Firms with market power maximize profits but the output decision will influence pricing.
Monopolists tend to produce less compared to perfectly competitive environments.
Condition for profit maximization:
MR
eq P ext{ and } MR = MC
Graphical Approach Example
Consider the iPad market where Apple's marginal cost of production is constant at $200 per unit.
Steps to determine profit-maximizing quantity:
Derive the marginal revenue curve from the demand curve.
Identify the quantity where marginal revenue equals marginal cost.
Find the profit-maximizing price on the demand curve.
Profit Maximization Graph
Figure 9.3 presents:
Price ($/iPad) on the Y-axis.
Quantity of iPads on the X-axis.
With optimal price $P* = 600 and quantity $Q* = 80 million.
Mathematical Profit Maximization
Demand equation example (iPads): Q = 200 - 0.2P To find profit-maximizing decisions:
Derive the marginal revenue from demand:
MR = 1000 - 10QSet MR = MC to find optimum quantity and calculate P:
MC = 200 ext{ leads to } 1000 - 10Q = 200
Optimal quantity $Q^* = 80$ million and price $P^* = 600$.
Lerner Index
The Lerner Index measures the firm's markup over marginal cost, revealing the level of market power.
The markup is defined as:
P - MC = rac{1}{Ed} where $Ed$ = elasticity of demand.
9.4 How a Firm with Market Power Reacts to Market Changes
Marginal Cost Changes
Similar to perfectly competitive firms, those with market power will alter output in response to changes in marginal costs.
Example: An issue at a parts supplier raises Apple's iPad production cost from $200 to $250.
Implication: Optimal production quantity decreases, which results in decreased pricing as well.
Example Graph Figure 9.4 shows:
$P1 = 600$, $P2 = 625$.
Initial/Decreased MC at 200 through 250.
Demand Changes
Outward demand shifts, for instance, due to increased iPad use in medical fields, affect market quantity and price.
New demand curve equation: P=1400-5Q
Find new profit-maximizing quantity through the same three-step process.
Price Sensitivity Changes
In cases where market dynamics shift consumer price sensitivity (as with new competing products), firms with market power react differently than those under perfect competition.
A case study: Introduction of the Kindle Fire by Amazon increases price elasticity for iPads, indicating a need for strategic price adjustments.
9.5 The Winners and Losers from Market Power
Evaluating the Impact of Market Power
Firms with market power may benefit, evident from consumer and producer surplus analysis.
Profit Calculations for iPads
Apple has marginal cost=$200 and price=$600, leading to:
Producer Surplus Calculation:
PS = (Pm - MC) imes Qm = (600 - 200) imes (80 ext{ million}) = 32 ext{ billion}
Consumer Surplus Analysis
Consumer surplus is the area under the demand curve above the sale price:
Calculate choke price (where quantity demanded = 0 for linear demand curves).
Under market power:
Use formula: CS = rac{1}{2} imes (P{choke} - Pm) imes Q_m
Example: with a $1,000 choke price:
CS = rac{1}{2} imes (1000 - 600) imes 80 = 16 ext{ billion}
Perfect Competition Outcomes
In a competitive environment, $P = MC = 200$ leads to:
Consumer surplus is maximized as seen from surplus area calculations.
Impact Analysis
Figure 9.6 displays various outcomes under competition and market power, highlighting:
Deadweight loss from market power as represented in surplus difference.
Efficiency Loss from Market Power
Firms reduce overall output below perfectly competitive levels, creating a deadweight loss typically equal to $16 billion in this assessed case.
9.6 Governments and Market Power: Regulation, Antitrust, and Innovation
Government Intervention Justifications
Deadweight loss serves as a rationale for governments to intervene through regulation seeking competitive outcomes.
Direct Price Regulation
Governments may regulate price contexts to achieve efficiency rather than combat monopoly directly:
Particularly applied in natural monopolies like utilities.
Antitrust Regulations
Antitrust laws restrict behaviors limiting market competition such as:
Mergers and acquisitions and price collusion.
Potentially difficult to measure impact and determine consumer benefit vs. market concentration.
Support for Innovation-based Monopolies
Government roles (patents, licensing) can incentivize innovation while balancing between market efficiency and consumer welfare reductions.
Rent-seeking behavior: Attempts by firms to obtain government-imposed monopoly positions instead of competition.
9.7 Conclusion
Summary of Key Points
Firms with market power do not regard output prices as fixed; they recognize the interdependencies between price and quantity.
Equilibrium output under such conditions is less than that enjoyed in perfect competition leading to deadweight loss.
Future discussions to consider price discrimination practices in advancing monopoly benefits.