In-Depth Notes on Exchange Rates, International Trade, and Capital Flows

Introduction to Exchange Rates
  • Definition: The nominal exchange rate is the rate at which two currencies can be traded for each other.
    • Example: If $1 = 104 Japanese yen, the nominal exchange rate between the U.S. dollar and the Japanese yen is 104 yen per dollar.
Appreciation and Depreciation of Currency

  • Appreciation: An increase in the value of a currency relative to other currencies.

    • Example: U.S. dollar appreciates from $1 = £0.5 to $1 = £0.6.

  • Depreciation: A decrease in the value of a currency relative to other currencies.

    • Example: Canadian dollar depreciates from C$1 = €96 to C$1 = €85.

  • Notation: Use the symbol "e" for a country’s nominal exchange rate (e.g., e represents the euros that one U.S. dollar will buy).

    • An increase in $e$ indicates appreciation of the domestic currency, while a decrease indicates depreciation.
Types of Exchange Rates
  • Flexible (Floating) Exchange Rates: Determined by demand and supply forces in the foreign exchange market.
  • Fixed Exchange Rates: Set by the government and not determined by the market forces (e.g. Hong Kong fixed to the U.S. dollar).
Determinants of Exchange Rates
Short-Run Analysis
  • Exchange rates are influenced by short-term demand and supply dynamics in the foreign currency market.
    • Example: U.S. citizens needing euros to buy European goods will supply dollars in exchange for euros.
Supply of Dollars
  • Sources:
    • U.S. individuals and firms looking to purchase foreign goods, assets, or services must supply dollars.
    • Supply curve is upward-sloping: Higher euro value per dollar prompts increased supply of dollars to the market.
Demand for Dollars
  • Sources:
    • Foreign consumers visiting the U.S. must demand dollars to purchase goods and services.
    • As the euro price per dollar drops, U.S. goods become cheaper, increasing attractiveness to foreign consumers.
Shifts in Supply and Demand Curves
Factors Influencing Supply Shifts
  • Increased U.S. travel to Europe raises the supply of dollars.
  • New desirable European products increase U.S. imports, shifting supply rightward.
  • Higher U.S. GDP leads to increased imports, hence a shift in dollar supply.
Factors Influencing Demand Shifts
  • Increased demand for U.S. goods by foreigners boosts demand for dollars rightward.
  • Growth in foreign GDP or higher interest rates on U.S. assets increases demand for dollars.
Economic Implications of Exchange Rates
  • A strong currency does not always indicate a strong economy.
    • An appreciating currency may reduce net exports (e.g., strong dollar leads to more imports, less exports).
    • Lower production costs from cheaper imports may enhance Aggregate Supply (AS) and GDP.
Monetary Policy and Exchange Rates
  • Key Relationship: Monetary policy significantly impacts exchange rates through real interest rates.
    • In an open economy with a floating exchange rate, increased interest rates can strengthen the dollar by raising demand and reducing supply.
  • Tightening Monetary Policy: Raises dollar demand and decreases supply, leading to appreciation.
  • Easing Monetary Policy: Reduces dollar demand and increases supply, resulting in depreciation.
Key Takeaways
  • Nominal exchange rates represent the trade rates between domestic and foreign currencies.
  • Floating exchange rates are market-determined.
  • Strong currencies may not correlate with strong economies.
  • Monetary policy affects exchange rates significantly; tighter policies lead to appreciation while looseness leads to depreciation.