Macroeconomics: Understanding National and Global Economies

GDP and Economic Measurement

Gross Domestic Product (GDP): total market value of all final goods and services produced within a country in a given period. Three approaches: expenditure (C + I + G + NX), income (wages + profits + rent + interest), production (value added across industries). Nominal GDP: measured at current prices. Real GDP: adjusted for inflation (using GDP deflator or chain-weighted index). GDP per capita: GDP divided by population — rough measure of living standards. GDP (PPP): Purchasing Power Parity adjustment — accounts for different price levels across countries. Limitations of GDP: doesn't capture inequality, environmental degradation, unpaid work, leisure, or well-being. Alternative measures: Human Development Index (HDI), Genuine Progress Indicator (GPI), Gross National Happiness (Bhutan). Leading economies (2025 nominal GDP): US (~$29T), China (~$19T), Germany (~$4.5T), Japan (~$4.2T), India (~$4T).

Inflation and Unemployment

Inflation: sustained increase in the general price level — measured by Consumer Price Index (CPI) and Personal Consumption Expenditures (PCE). Causes: demand-pull (too much money chasing too few goods), cost-push (supply shocks — oil prices, wages), built-in (wage-price spiral from expectations). Hyperinflation: >50% per month (Zimbabwe 2008: 79.6 billion % per month, Venezuela 2018: 1.3 million %). Deflation: falling prices — dangerous because it increases real debt burden, discourages spending (Japan's "lost decades"). Phillips Curve: inverse relationship between inflation and unemployment — Friedman added expectations (long-run vertical). NAIRU: Non-Accelerating Inflation Rate of Unemployment — the "natural rate" (~4-5% in developed economies). Types of unemployment: frictional (job search), structural (skill mismatch), cyclical (recession-driven). Okun's Law: 1% above natural unemployment ≈ 2% below potential GDP.

Monetary and Fiscal Policy

Monetary policy: central bank controls money supply and interest rates. Federal Reserve (US), ECB (Europe), Bank of Japan, Bank of England. Tools: federal funds rate (overnight interbank rate), open market operations (buying/selling government bonds), reserve requirements, quantitative easing (QE — buying long-term assets). Taylor Rule: systematic formula for setting interest rates based on inflation gap and output gap. Quantitative Tightening (QT): reversing QE by reducing central bank balance sheet — underway since 2022. Fiscal policy: government spending and taxation. Expansionary: increase spending / cut taxes during recession (Keynesian). Contractionary: reduce spending / raise taxes to cool overheating economy. Automatic stabilizers: unemployment insurance, progressive taxation — stabilize without legislative action. Government debt: US national debt >$36 trillion (2025), debt-to-GDP ~125%. Modern Monetary Theory (MMT): controversial — argues sovereign currency issuers can't default, constraint is inflation not debt.

Business Cycles and Trade

Business cycle: expansion → peak → contraction (recession) → trough → recovery. NBER: official US recession arbiter — two or more quarters of declining GDP is a rough guide, but NBER uses broader criteria. Great Recession (2007-2009): triggered by housing bubble, subprime mortgage crisis, financial system near-collapse. COVID recession (2020): shortest on record (2 months) but deepest since WWII — GDP fell 31.4% annualized in Q2 2020. Recovery: massive fiscal stimulus ($5T+) and monetary easing drove rapid rebound but also inflation. International trade: comparative advantage (Ricardo) — countries benefit from specializing in goods they produce at lower opportunity cost. Trade balance: exports minus imports — US runs persistent trade deficit (~$800B/year). WTO: governs international trade rules, dispute resolution. Trade wars: US-China tariffs (2018-present) disrupted supply chains and raised costs. Globalization trends: nearshoring, friend-shoring, supply chain resilience becoming priorities post-COVID.

❓ Frequently Asked Questions

Gross Domestic Product (GDP): total market value of all final goods and services produced within a country in a given period. Three approaches: expenditure (C + I + G + NX), income (wages + profits + ...

Inflation: sustained increase in the general price level — measured by Consumer Price Index (CPI) and Personal Consumption Expenditures (PCE). Causes: demand-pull (too much money chasing too few goods...

Monetary policy: central bank controls money supply and interest rates. Federal Reserve (US), ECB (Europe), Bank of Japan, Bank of England. Tools: federal funds rate (overnight interbank rate), open m...

Business cycle: expansion → peak → contraction (recession) → trough → recovery. NBER: official US recession arbiter — two or more quarters of declining GDP is a rough guide, but NBER uses broader crit...

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