Microeconomics: Market Structures, Costs, and Efficiency – Exam 3 Study Guide

Chapter 11: Technology, Production, and Costs

Technological Change

Technological change refers to improvements in the methods of producing goods and services, often resulting in increased productivity and lower costs.

• Definition: A change in the ability of a firm to produce a given level of output with a given quantity of inputs.

• Example: Automation in manufacturing increases output per worker.

Short Run vs. Long Run

The distinction between the short run and long run is crucial in production and cost analysis.

• Short Run: At least one input is fixed (e.g., capital).

• Long Run: All inputs are variable; firms can adjust all factors of production.

• Example: In the short run, a bakery can hire more workers but cannot expand its building; in the long run, it can do both.

Cost Calculations

• Total Cost (TC): The sum of all costs incurred in production. $TC = FC + VC$

• Fixed Cost (FC): Costs that do not vary with output (e.g., rent).

• Variable Cost (VC): Costs that change with the level of output (e.g., raw materials).

• Profit: The difference between total revenue and total cost. $\text{Profit} = TR - TC$

• Average Total Cost (ATC): Total cost per unit of output. $ATC = \frac{TC}{Q}$

• Average Variable Cost (AVC): Variable cost per unit of output. $AVC = \frac{VC}{Q}$

• Average Fixed Cost (AFC): Fixed cost per unit of output. $AFC = \frac{FC}{Q}$

• Marginal Revenue (MR): The additional revenue from selling one more unit. $MR = \frac{\Delta TR}{\Delta Q}$

• Marginal Cost (MC): The additional cost of producing one more unit. $MC = \frac{\Delta TC}{\Delta Q}$

• Marginal Product (MP): The additional output from using one more unit of input. $MP = \frac{\Delta Q}{\Delta L}$

Explicit vs. Implicit Costs

• Explicit Costs: Direct, out-of-pocket payments (e.g., wages, rent).

• Implicit Costs: Opportunity costs of using resources owned by the firm (e.g., foregone salary).

Division of Labor and Specialization

• Division of Labor: Breaking down production into distinct tasks performed by different workers.

• Specialization: Workers focus on specific tasks, increasing efficiency.

• Example: Assembly lines in car manufacturing.

Law of Diminishing Returns

• As more units of a variable input are added to fixed inputs, the additional output from each new unit will eventually decrease.

• Example: Adding more workers to a fixed-size kitchen increases output at first, but eventually, overcrowding reduces productivity.

Short Run ATC vs. Long Run ATC

• Short Run ATC: Includes fixed and variable costs; each plant size has its own ATC curve.

• Long Run ATC: Shows the lowest possible cost at which any output can be produced when all inputs are variable.

Economies of Scale

• When increasing production lowers average total cost in the long run.

• Causes: Specialization, bulk buying, efficient capital use.

• Diseconomies of Scale: When increasing production raises average total cost.

Chapter 12: Firms in Perfectly Competitive Markets

Assumptions of Perfect Competition

• Many buyers and sellers.

• Identical (homogeneous) products.

• No barriers to entry or exit.

• Perfect information.

Zero Economic Profit in the Long Run

• Firms enter or exit the market until economic profit is zero (normal profit).

Price Taker

• Firms accept the market price; they cannot influence it.

Demand Curve for a Perfectly Competitive Firm

• Perfectly elastic at the market price (horizontal line).

Shutdown Condition

• A firm should shut down in the short run if price is less than average variable cost (P < AVC).

Productive vs. Allocative Efficiency

• Productive Efficiency: Producing at the lowest possible cost (where ATC is minimized).

• Allocative Efficiency: Producing the mix of goods most desired by society (where P = MC).

Identifying Profit Maximization Output

• Firms maximize profit where marginal cost equals marginal revenue (MC = MR).

Profit, Loss, and Breakeven on a Graph

• Profit: Price > ATC at the profit-maximizing output.

• Loss: Price < ATC at the profit-maximizing output.

• Breakeven: Price = ATC at the profit-maximizing output.

Chapter 13: Monopolistic Competition

Characteristics and Comparison to Perfect Competition

• Many firms, differentiated products, free entry and exit.

• Firms have some market power due to product differentiation.

• In the long run, firms earn zero economic profit, but price > MC and ATC is not minimized.

Identifying Profit, Loss, or Breakeven in a Graph

• Similar to perfect competition, but the demand curve is downward sloping.

• Profit: Price > ATC; Loss: Price < ATC; Breakeven: Price = ATC.

Allocative and Productive Efficiency vs. Perfect Competition

• Monopolistic competition is neither allocatively nor productively efficient.

• Perfect competition achieves both efficiencies.

Chapter 14: Oligopoly

Oligopoly and Concentration Ratios

• Oligopoly: A market with a few large firms dominating the industry.

• Concentration Ratio: Measures the market share of the largest firms (e.g., four-firm concentration ratio).

Reasons for Oligopolies

• Barriers to entry (e.g., economies of scale, patents, control of resources).

• Mergers and acquisitions.

Game Theory Concepts

• Prisoner’s Dilemma: A situation where rational choices lead to a worse outcome for all participants.

• Dominant Strategy: A strategy that is best regardless of what others do.

• Nash Equilibrium: No player can improve their outcome by changing their strategy unilaterally.

• Collusion: Firms cooperate to set prices or output, reducing competition.

• Cooperative Equilibrium: Firms coordinate strategies for mutual benefit.

Chapter 15: Monopoly

Reasons for Monopolies

• Control of key resources.

• Government-created barriers (patents, copyrights).

• Network externalities (value increases as more use the product).

• Natural monopoly (cost advantages due to large scale).

Productive and Allocative Efficiency vs. Perfect Competition

• Monopolies are not productively or allocatively efficient.

• Price > MC, and output is less than the socially optimal level.

Deadweight Loss in a Graph

• Monopoly pricing creates deadweight loss: lost gains from trade due to reduced output.

Natural and Regulated Monopolies

• Natural Monopoly: One firm can supply the entire market at lower cost than multiple firms.

• Regulated Monopoly: Government controls prices and output to limit market power.

Market Power and Price Maker

• Monopolies set prices above marginal cost (price makers).

Price Discrimination

• Charging different prices to different consumers for the same good.

• Example: Airline tickets, student discounts.

Horizontal vs. Vertical Mergers

• Horizontal Merger: Between firms in the same industry.

• Vertical Merger: Between firms at different stages of production.

DOJ/FTC Merger Guidelines and Herfindahl-Hirschman Index (HHI)

• HHI: Measures market concentration; higher values indicate less competition. $HHI = \sum_{i=1}^{N} s_i^2$ (where $s_i$ is the market share of firm $i$ in percentage points)

• DOJ/FTC use HHI to evaluate potential anti-competitive effects of mergers.

Antitrust Laws: Sherman Act and Clayton Act

• Sherman Act (1890): Prohibits monopolization and restraint of trade.

• Clayton Act (1914): Addresses specific practices like price discrimination and mergers that lessen competition.