Economics: Market Structures, Antitrust, and Regulation

Comprehensive vocabulary flashcards covering Market Structures (Perfect Competition, Monopoly, Monopolistic Competition, Oligopoly), Game Theory, Antitrust Policy, and Government Regulation based on Chapters 9 through 12.

Market Structure

The environment whose characteristics influence a firm's pricing and output decisions, primarily categorized into perfect competition, monopolistic competition, oligopoly, and monopoly.

Perfect Competition

A market structure theory based on four core assumptions: many buyers and many sellers, each firm selling an identical (homogeneous) product, all buyers and sellers having all relevant information, and easy entry into and exit from the market.

Price Taker

A seller that lacks the ability to control the price of the product it sells and must accept the price determined in the market; faces a horizontal, perfectly elastic demand curve ($E_d = \infty$).

Marginal Revenue ($MR$)

The change in total revenue ($\text{TR}$) resulting from selling one additional unit of output ($Q$), defined by the formula $MR = \frac{\Delta \text{TR}}{\Delta Q}$. For a perfectly competitive firm, price equals marginal revenue ($P = MR$).

Resource Allocative Efficiency

The economic condition achieved when firms produce the output level at which the price of the good equals marginal cost ($P = MC$), ensuring resources are allocated according to consumer preferences.

Short-Run Firm Supply Curve

The portion of a perfectly competitive firm's marginal cost ($MC$) curve that lies above its average variable cost ($AVC$) curve.

Short-Run Market Supply Curve

The horizontal summation of all individual existing firms' short-run supply curves within an industry.

Shutdown Rule

A short-run decision principle stating that a firm should cease production if price is less than average variable cost ($P < AVC$) or total revenue is less than total variable cost ($\text{TR} < \text{TVC}$), limiting short-run losses to total fixed costs ($\text{TFC}$).

Productive Efficiency

The condition wherein a firm produces its output at the lowest possible per-unit cost, corresponding to the minimum point on its average total cost ($\text{ATC}$) curve.

Long-Run Competitive Equilibrium

The condition in a perfectly competitive industry where $P = MC = \text{SRATC} = \text{LRATC}$, resulting in zero economic profits, minimum average total cost production, and no incentive for firms to enter, exit, or alter plant size.

Constant-Cost Industry

An industry in which average total costs ($\text{ATC}$) do not change as output changes when firms enter or exit the industry, producing a horizontal long-run supply curve.

Increasing-Cost Industry

An industry in which average total costs ($\text{ATC}$) rise as output expands and fall as output contracts when firms enter or exit the industry, resulting in an upward-sloping long-run supply curve.

Decreasing-Cost Industry

An industry in which average total costs ($\text{ATC}$) decrease as industry output expands and increase as output contracts, resulting in a downward-sloping long-run supply curve.

Monopoly

A market structure based on three assumptions: there is a single seller, the product sold has no close substitutes, and barriers to entry are extremely high.

Public Franchise

A government-granted right that permits a specific firm to provide a particular good or service while legally excluding all other firms from doing so.

Natural Monopoly

A market condition in which economies of scale are so pronounced over the relevant output range that only a single firm can survive and achieve lowest per-unit costs.

Price Searcher

A seller with the ability to control, to some degree, the price of the good it sells, facing a downward-sloping demand curve where price exceeds marginal revenue ($P > MR$).

Deadweight Loss of Monopoly

The net loss in social welfare and consumer surplus resulting from a monopoly producing less than the competitive quantity where $P = MC$, graphically represented by a deadweight loss triangle.

Rent Seeking

The expenditure of scarce resources by individuals or groups to influence public policy or government actions in order to transfer wealth or create monopoly profits for themselves.

X-Inefficiency

An increase in production costs caused by organizational slack and a lack of competitive pressure on a monopolist to operate at the lowest possible cost.

Price Discrimination

A pricing practice where a seller charges different prices for identical units of a product, and the differences in price are not attributable to differences in production costs.

Perfect Price Discrimination (First-Degree)

A price scheme in which the seller charges the maximum price each buyer is willing to pay for each individual unit, converting all consumer surplus into revenue such that $P = MR$ and achieving allocative efficiency.

Second-Degree Price Discrimination

A pricing structure in which a seller charges a uniform price per unit for a specific quantity block and lower per-unit prices for additional quantities purchased.

Third-Degree Price Discrimination

A pricing practice where a seller charges different prices across distinct consumer groups or different markets based on differing price elasticities of demand.

Arbitrage

The practice of buying a good at a lower price in one market and simultaneously selling it at a higher price in another market to earn a profit.

Monopolistic Competition

A market structure based on three assumptions: many buyers and many sellers, each firm selling a slightly differentiated product, and easy entry into and exit from the industry.

Excess Capacity Theorem

The proposition that in long-run equilibrium, a monopolistically competitive firm produces an output level ($q^*$) that is smaller than the output level that minimizes average total cost ($q_{\min}$).

Oligopoly

A market structure characterized by few sellers with high mutual interdependence, many buyers, homogeneous or differentiated products, and significant barriers to entry.

Concentration Ratio

The percentage of total industry sales (or output, assets, or employment) accounted for by a specified number of the largest firms in the industry, commonly calculated as the four-firm ($\text{CR}_4$) or eight-firm ($\text{CR}_8$) ratio.

Cartel

A formal organization of independent firms within an oligopoly that colludes to restrict output and raise prices in order to earn monopoly-level joint profits.

Game Theory

A mathematical technique used to model and analyze strategic interactions among decision-makers whose outcomes depend directly on the actions of all participants.

Prisoner's Dilemma

A game theory model demonstrating that individually rational choices by self-interested participants can lead to a jointly suboptimal and inefficient outcome for all players.

Contestable Market

A market characterized by costless entry and exit, new entrants capable of producing at the same costs as incumbent firms, and exiting firms able to easily dispose of their fixed assets without sunk loss.

Hit-and-Run Entry

The rapid entry of a firm into a contestable market to capture temporary economic profits followed by a costless exit when prices fall back to cost.

Antitrust Law

Legislation enacted for the stated purpose of controlling monopoly power, preventing combinations in restraint of trade, and preserving and promoting competitive markets.

Trust

A combination or business alliance of previously independent firms that operate collectively to act as a monopoly.

Sherman Act (1890)

The landmark federal antitrust statute that made illegal combinations, contracts, or conspiracies in restraint of trade and prohibited monopolization or attempts to monopolize.

Clayton Act (1914)

Antitrust legislation that outlawed specific anti-competitive business practices where their effect substantially lessens competition, including price discrimination, tying contracts, exclusive dealing, and horizontal stock acquisitions.

Federal Trade Commission Act (1914)

Federal legislation that established the Federal Trade Commission ($\text{FTC}$) and declared illegal unfair methods of competition in commerce.

Robinson-Patman Act (1936)

An amendment to the Clayton Act designed to protect independent small businesses by prohibiting suppliers from offering special pricing discounts exclusively to large chain stores.

Wheeler-Lea Act (1938)

Legislation amending the Federal Trade Commission Act that granted the $\text{FTC}$ authority to prohibit unfair or deceptive practices, explicitly addressing false and misleading advertising.

Celler-Kefauver Antimerger Act (1950)

An amendment closing a major loophole in the Clayton Act by expanding federal authority to ban anticompetitive mergers accomplished through physical asset acquisition in addition to stock purchase.

Herfindahl Index

An industry concentration metric calculated by summing the squares of the individual market shares of all firms in the industry: $\text{Herfindahl Index} = (S_1)^2 + (S_2)^2 + \dots + (S_n)^2$.

Horizontal Merger

A business combination between two or more competing firms that sell similar products in the same market.

Vertical Merger

A combination between companies operating at different stages of the production or distribution process within the same industry.

Conglomerate Merger

A merger uniting companies that operate across completely unrelated industries.

Network Good

A good or service whose value to an individual consumer increases as the expected total number of users or units sold increases.

Lock-in Effect

A market scenario where a particular technology or product becomes the established standard, creating switching costs so high that consumers cannot easily migrate to alternative goods.

Regulatory Lag

The delay between the time a regulated natural monopoly's operating costs change and the time the regulatory agency approves an adjustment to allowable rates or prices.

Capture Theory of Regulation

A theory positing that regardless of the original protective motives for regulation, regulatory agencies eventually become controlled (captured) by the special interests of the industry they regulate.

Public Interest Theory of Regulation

A theory holding that regulatory bodies act objectively in the best interest of consumers and society at large to correct market failures.

Public Choice Theory of Regulation

A theory asserting that regulatory officials behave as self-interested actors seeking to maximize their own personal authority, career benefits, agency size, and administrative budgets.

Natural Monopoly Regulation

The government oversight of a natural monopoly through price regulation (marginal cost pricing where $P = MC$), profit regulation (average cost pricing where $P = \text{ATC}$), or mandated output regulation.