Economics March 3, 2026 6 min read

Parts 12-13: Economic Growth and International Economy (Ch33~Ch38)

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Part 12. The Economics of Economic Growth

Chapter 33. Economic Growth Theories

1. Solow Growth Model (Exogenous Growth)

The neoclassical economist Solow assumes labor and capital are input factors of production.

  • Diminishing Marginal Returns to Capital: As capital is continuously added, the output generated by each additional unit of capital gradually decreases.
  • Steady State: A stationary state where new investment exactly offsets depreciation plus population growth. In this state, the growth rate of per capita national income = 0.
  • The Role of Technological Progress: The force that breaks through the limitations of the steady state. Assumed to fall from outside the model (exogenous) → the source of sustained growth.

2. Endogenous Growth Theory (Lucas, Romer)

Why can developed countries widen the gap with developing countries?

  • Increasing Returns to Knowledge and Human Capital: R&D and education investments generate external effects, enabling sustained growth.
  • The Logic of Government Intervention: Knowledge has the characteristics of a public good → the private sector underinvests (market failure) → justifies state subsidies for education and R&D.

3. Comparison of Trade Development Strategies

StrategyContentAdvantagesDisadvantages
Export-ledExport-focused growth (Korean model)Securing economies of scale, fast technology transferExcessive external dependence
Import-substitutionPrioritizing domestic market protection and breaking away from foreign influence (Latin America)Protecting domestic industriesScale limitations, closed nature

Part 13. International Economics

Chapters 34–35. International Trade System

1. Theory of Comparative Advantage (Ricardo)

If any country specializes in and trades goods with a relatively low opportunity cost, the wealth of both countries increases (gains from trade).

2. Comparison of Tariffs vs. Import Quotas

ClassificationTariffImport Quota
ConceptImposing a tax on imported goodsSetting a legal limit on the import volume itself
Domestic PriceArtificially higher than the international priceArtificially higher than the international price
Recipient of Excess ProfitDomestic government (national treasury)Holders of import monopoly licenses (generates quota rent)
Policy TransparencyHighLow (risk of corruption and rent-seeking)

Chapter 36. Exchange Rate Structure and Monetary Systems

1. Exchange Rate Fluctuation Direction and Determinants

Rise in exchange rate (KRW/USD) = Depreciation of the Korean Won = Strong Dollar

Macroeconomic IndicatorImpact on Exchange Rate
Current Account SurplusForeign currency supply ↑ → Exchange rate ↓
Current Account DeficitForeign currency demand ↑ → Exchange rate ↑
Domestic Interest Rate > Foreign Interest RateOverseas capital inflow ↑ → Foreign currency supply ↑ → Exchange rate ↓
Domestic Price RiseExports ↓, Imports ↑ → Foreign currency demand ↑ → Exchange rate ↑
  1. Exporting Companies (Positive): Dollar-denominated prices fall → Temporary increase in price competitiveness 2. Companies Repaying Foreign Debt, Overseas Travel, and Importers (Negative): Surge in won-denominated costs 3. Domestic Prices (Negative): Rise in imported raw material prices → Cost-push inflation 4. When Marshall-Lerner Condition is Met: Medium-to-long-term improvement in the trade balance after a short-term J-curve effect

2. Floating vs. Fixed Exchange Rate Systems: Monetary and Fiscal Policy Effects (Mundell-Fleming)

Based on an open economy with small-scale free capital mobility.

PolicyFloating Exchange Rate SystemFixed Exchange Rate System
Monetary PolicyMaximization of effect (Money ↑ → Interest rate ↓ → Capital outflow → Exchange rate ↑ → Net exports ↑)Neutralization of effect (Money ↑ → Upward pressure on exchange rate → Central bank sells foreign currency → Money supply returns to original level)
Fiscal PolicyNeutralization of effect (Spending ↑ → Interest rate ↑ → Capital inflow → Exchange rate ↓ → Net exports ↓ → Crowding-out effect)Maximization of effect (Spending ↑ → Interest rate ↑ → Capital inflow → Increase money supply to defend against falling exchange rate → Amplification of economic expansion)

Chapter 37. The Marshall-Lerner Condition and the J-Curve Effect

  • Marshall-Lerner Condition: For a rise in the exchange rate to lead to an increase in net exports, the sum of the price elasticity of exports and the price elasticity of imports must be > 1.
  • J-Curve Effect: Immediately after a rise in the exchange rate, net exports actually decrease due to short-term contracts and other factors, only to increase after a considerable period of time. The graph takes the shape of the letter J.

Causes of the J-Curve Effect

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Chapter 38. The Economics of Crisis

1. Structure of the 2008 Global Financial Crisis

Transmission Path of the Subprime Mortgage Crisis

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2. Quantitative Easing (QE)

An unconventional monetary policy used when economic recovery is insufficient even after lowering policy interest rates to 0%.

  • The central bank directly purchases large quantities of medium-to-long-term government bonds and asset-backed securities on a large scale → Directly supplies liquidity to the market.
  • Effects: Fall in medium-to-long-term interest rates, expansion of bank lending capacity, rise in asset prices, increase in consumption (wealth effect).
  • Side Effects: Emerging market asset bubbles, deepening income inequality, long-term inflation risk, uncertainty of exit strategies.

3. Relationship Between Keynes’s Liquidity Trap and Quantitative Easing

When interest rates approach 0%, bond prices are so high that everyone expects prices to fall. The interest rate elasticity of money demand is infinite → Even if the money supply is increased, interest rates do not fall at all → Monetary policy is completely paralyzed. Keynes argued that in this situation, fiscal policy is the only solution. Quantitative easing emerged after 2008 to overcome the limitations of traditional monetary policy.

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