Microeconomics
Supply & Demand
The foundational model of price determination in competitive markets. The intersection of supply and demand curves establishes equilibrium price and quantity, governed by the law of demand (inverse price-quantity relationship) and the law of supply (direct price-quantity relationship). Market forces continuously push prices toward equilibrium through the mechanism of surplus and shortage.
P = f(Q)Elasticity
The measure of responsiveness of one economic variable to changes in another. Price elasticity of demand quantifies how quantity demanded changes relative to price changes, classified as elastic (|E| > 1), inelastic (|E| < 1), or unit elastic (|E| = 1).
Marginal Analysis
The examination of the additional benefits of an activity compared to the additional costs incurred. Rational agents optimize by equating marginal benefit to marginal cost at the decision margin.
Utility Theory
The framework for modeling consumer preferences and choice behavior. Cardinal utility assigns numerical values to satisfaction levels, while ordinal utility ranks preferences without measurement. Indifference curves represent combinations of goods yielding equal satisfaction, with the budget constraint determining the optimal consumption bundle at the tangency point.
Market Structures
The classification of markets by competitive intensity: perfect competition (many small firms, homogeneous goods), monopolistic competition (many firms, differentiated goods), oligopoly (few dominant firms), and monopoly (single seller). Each structure yields distinct price, output, and efficiency outcomes.
Externalities
Costs or benefits imposed on third parties not directly involved in a transaction. Negative externalities (pollution, congestion) cause overproduction relative to the social optimum; positive externalities (education, vaccination) cause underproduction. Pigouvian taxes and subsidies internalize these spillover effects.
Macroeconomics
Gross Domestic Product
The total monetary value of all finished goods and services produced within a country's borders in a specific time period. GDP serves as the broadest quantitative measure of economic activity, calculated through expenditure (C + I + G + NX), income, or production approaches. Real GDP adjusts for inflation using a base-year price level, while nominal GDP reflects current prices.
$25.5TInflation
The sustained increase in the general price level of goods and services over time, eroding purchasing power. Measured by Consumer Price Index (CPI) and GDP deflator. Demand-pull inflation arises from excess aggregate demand; cost-push inflation stems from rising production costs.
Unemployment
The condition where labor force participants actively seeking employment cannot find work. Classified as frictional (transitional), structural (skills mismatch), cyclical (demand-driven), and seasonal. The natural rate of unemployment represents the non-accelerating inflation rate (NAIRU).
Monetary Policy
Central bank actions controlling money supply and interest rates to achieve macroeconomic objectives. Expansionary policy lowers rates and increases money supply to stimulate growth; contractionary policy raises rates to control inflation. Tools include open market operations, reserve requirements, discount rates, and quantitative easing.
Fiscal Policy
Government adjustments to spending levels and tax rates to influence aggregate demand and economic performance. Discretionary fiscal policy involves deliberate changes, while automatic stabilizers (progressive taxes, unemployment benefits) respond counter-cyclically without legislative action.
Business Cycles
Recurring fluctuations in economic activity measured by real GDP. The four phases -- expansion, peak, contraction (recession), and trough -- form a cyclical pattern influenced by aggregate demand shocks, supply disruptions, financial crises, and policy responses.
Trade
Comparative Advantage
David Ricardo's principle that nations benefit from trade by specializing in goods they produce at the lowest opportunity cost, even if one nation holds absolute advantage in all goods. The theory demonstrates that voluntary exchange creates mutual gains through specialization and trade, forming the theoretical foundation for free trade advocacy.
Balance of Payments
The systematic record of all economic transactions between residents of a country and the rest of the world. Comprises the current account (trade in goods/services, income), capital account (capital transfers), and financial account (investment flows). The BOP must balance by definition.
Exchange Rates
The price of one currency expressed in terms of another. Determined by supply and demand in foreign exchange markets under floating regimes, or maintained by central bank intervention under fixed/pegged regimes. Purchasing power parity and interest rate parity provide long-run equilibrium benchmarks.
Trade Policy
Government interventions regulating international commerce through tariffs (import taxes), quotas (quantity limits), subsidies (domestic production support), and trade agreements (bilateral/multilateral liberalization). Protectionist policies shield domestic industries but impose deadweight losses and invite retaliation. The World Trade Organization provides the multilateral framework for dispute resolution and progressive trade liberalization through successive negotiation rounds.
164 WTO MEMBERSGlobalization
The increasing integration of national economies through cross-border flows of goods, services, capital, labor, and information. Driven by technological change, policy liberalization, and institutional development since the post-WWII Bretton Woods era.
Economic Development
The process of improving living standards, institutional capacity, and productive capability in lower-income economies. Distinguished from mere growth by encompassing structural transformation, human capital accumulation, poverty reduction, and institutional strengthening.
Finance
Financial Markets
Organized venues where financial instruments are traded, facilitating the allocation of capital from savers to borrowers. Primary markets issue new securities; secondary markets trade existing ones. Money markets handle short-term instruments (under one year); capital markets deal in long-term securities including equities and bonds.
Banking System
The institutional framework of financial intermediation. Commercial banks accept deposits and make loans, creating money through fractional reserve lending. Central banks serve as lender of last resort, conduct monetary policy, and supervise the banking system to maintain financial stability.
Risk & Return
The fundamental trade-off in finance: higher expected returns require accepting greater risk. Portfolio theory (Markowitz) demonstrates that diversification reduces unsystematic risk. The Capital Asset Pricing Model relates expected return to systematic risk (beta) through the security market line.
Derivatives & Financial Engineering
Financial instruments whose value derives from an underlying asset, rate, or index. Options grant the right (not obligation) to buy or sell at a predetermined price. Futures obligate both parties to transact at a future date. Swaps exchange cash flow streams between counterparties. The Black-Scholes model provides theoretical option pricing through no-arbitrage arguments and stochastic calculus. Credit derivatives (CDS) transfer default risk, while structured products (CDOs, MBS) repackage cash flows into tranches of varying seniority and risk profiles.
$632T NOTIONAL VALUEBehavioral Finance
The study of psychological influences on investor behavior and market outcomes. Cognitive biases (overconfidence, anchoring, loss aversion) and heuristics cause systematic deviations from rational expectations, producing anomalies like bubbles, momentum, and the equity premium puzzle.
Financial Regulation
The legal and institutional framework governing financial markets and institutions. Basel accords set international banking capital standards. Dodd-Frank reformed U.S. financial regulation post-2008. Regulatory objectives balance systemic stability, consumer protection, and market efficiency.
Policy
Public Economics
The study of government economic activity: taxation, public expenditure, and their effects on resource allocation and income distribution. Public goods (non-rival, non-excludable) represent market failures requiring government provision. Tax policy design balances efficiency (minimizing deadweight loss) against equity (ability-to-pay, benefit principles). The Laffer curve illustrates the non-monotonic relationship between tax rates and revenue. Social welfare functions aggregate individual utilities into collective well-being measures, informing redistribution policy.
36% AVG TAX-TO-GDP (OECD)Labor Policy
Government regulation of labor markets: minimum wage laws, workplace safety standards, collective bargaining rights, and anti-discrimination statutes. Debates center on the employment effects of minimum wages, the role of unions, and the design of social insurance programs.
Environmental Economics
The application of economic principles to environmental issues. Carbon pricing (cap-and-trade, carbon taxes) internalizes climate externalities. Cost-benefit analysis evaluates environmental regulations. The Coase theorem suggests private bargaining can resolve externalities when property rights are well-defined and transaction costs low.
Inequality & Redistribution
The analysis of income and wealth distribution across populations. The Gini coefficient measures inequality on a 0-1 scale. Lorenz curves display cumulative income shares. Progressive taxation and transfer programs (EITC, universal basic income proposals) aim to reduce inequality while maintaining incentive compatibility. The equity-efficiency trade-off remains a central tension in policy design.
Competition Policy
Antitrust enforcement preventing monopolistic practices, cartels, and anti-competitive mergers. The Herfindahl-Hirschman Index measures market concentration. Policy interventions range from structural remedies (break-ups) to behavioral remedies (conduct restrictions) to promote competitive markets.
Welfare Economics
The normative branch evaluating social desirability of economic outcomes. Pareto efficiency, Kaldor-Hicks compensation, and social welfare maximization provide distinct criteria. Arrow's impossibility theorem demonstrates that no voting system satisfies all fairness axioms simultaneously.
History
Classical Economics
The founding tradition from Adam Smith's "Wealth of Nations" (1776) through David Ricardo, Thomas Malthus, and John Stuart Mill. Established the labor theory of value, the doctrine of laissez-faire, the principle of comparative advantage, and the quantity theory of money. Say's Law postulated that supply creates its own demand, a proposition that would define the central debate in macroeconomics for two centuries.
1776Marginalist Revolution
The simultaneous 1870s discovery by Jevons, Menger, and Walras that value derives from marginal utility, not labor content. Transformed economics into a mathematical discipline of constrained optimization, establishing the neoclassical paradigm of rational agents maximizing utility subject to budget constraints.
Keynesian Economics
John Maynard Keynes's revolutionary "General Theory" (1936) argued that aggregate demand determines output and employment, that economies can settle at below-full-employment equilibria, and that government fiscal intervention is necessary to stabilize cyclical fluctuations. The Keynesian framework dominated postwar macroeconomic policy.
Modern Schools of Thought
The post-Keynesian intellectual landscape fractured into competing paradigms. Monetarism (Friedman) emphasized money supply control over fiscal activism. New Classical economics (Lucas, Sargent) introduced rational expectations and policy ineffectiveness propositions. New Keynesian economics (Mankiw, Stiglitz) rehabilitated Keynesian insights with microfoundations -- sticky prices, imperfect competition, and information asymmetries. Austrian economics (Hayek, Mises) stressed spontaneous order, entrepreneurial discovery, and skepticism of central planning. Institutional economics (North, Acemoglu) emphasized the role of institutions, property rights, and governance structures in economic outcomes.
Econometrics
The application of statistical methods to economic data for testing hypotheses and forecasting. Regression analysis, time-series methods, and causal inference techniques (instrumental variables, difference-in-differences, regression discontinuity) form the empirical toolkit of modern economics.
Game Theory
The mathematical study of strategic interaction where outcomes depend on the choices of multiple agents. Nash equilibrium identifies stable strategy profiles. Applications span oligopoly pricing, auction design, mechanism design, and the analysis of cooperation and conflict in economic settings.