Lectures 3+4 - Price levels and the exchange rate in the long run

16. Price Levels and Exchange Rates in the Long-Run

16.1 Long-Run Approach

  • Flexible Prices: In the long run, prices are considered perfectly flexible.

  • Increase in Money Supply (M↑): This leads to an increased demand for goods, which causes increasing price levels (P↑).

    • This results in the ratio of money to prices (M/P) returning to its original level.

  • Demand Relationships:

    • Demand for domestic goods relative to foreign goods decreases.

    • Demand for domestic currency decreases relative to foreign currency, resulting in an increase in the exchange rate (depreciation of domestic currency).

16.2 Models to Predict Exchange Rates

  • Short-Run vs Long-Run:

    • Short-run: An increase in M causes a change in exchange rates through asset demand for currencies (M → R → demand for financial assets → demand for currencies → exchange rate).

    • Long-run: Adjusts P mitigates initial exchange rate changes (M → P → demand for goods and currencies → exchange rate).

  • Key Approaches:

    • Law of One Price and Purchasing Power Parity (PPP) contribute to long-run models of exchange rates.

16.3 Key Concepts and Relationships

  • Purchasing Power Parity (PPP): Implies that the ratio of average prices across countries determines exchange rates.

    • If a basket of goods costs 100 EUR in the Eurozone and 200 CHF in Switzerland, the implied exchange rate under PPP is 1/2.

  • Fisher Effect: The relationship between nominal interest rates and inflation, stating that the expected nominal interest rate equals the real interest rate plus anticipated inflation.

16.4 Law of One Price

  • Definition: If free trade is costless, identical goods should sell for the same price across different countries.

  • Arbitrage Mechanism: When price differences exist, arbitrage occurs until prices adjust to equality.

16.5 Violation of Law of One Price

  • Reasons for Violation:

    • Tax Differences: Variations in taxation across countries affect pricing.

    • Transportation Costs: Increase the cost of goods thus leading to price variations.

    • Competition Forms: Different market structures across countries can lead to different price levels.

16.6 Purchasing Power Parity (PPP)

  • PPP Application: Applies to baskets of goods and services across countries.

  • Average Price Level: Average price levels (PNL for Netherlands, PCH for Switzerland) express relationship between currencies (EUR/CHF exchange rate).

16.7 Average Prices and Exchange Rates

  • Absolute vs Relative PPP:

    • Absolute PPP holds when exchange rates equal relative average prices.

    • Relative PPP holds if exchange rate changes correspond to changes in price levels.

16.8 Real Exchange Rate Approach

  • Definition: The real exchange rate reflects the rate of exchange for goods and services, factoring in relative price differences.

  • Determinants:

    1. Nominal Exchange Rate

    2. World Relative Demand: Increased relative demand for goods raises their value relative to others.

    3. Relative Supply: Changes in the relative supply can also impact prices and exchange rates.

16.9 Interest Rate Differences and the Fisher Effect

  • Expected Changes in Real and Nominal Exchange Rates: Nominal rate changes relate to expected inflation and real depreciation rates.

    • Real Interest Rates: Measured in terms of output and encompassing the effects of inflation.

16.10 Real Interest Rates and Expectations

  • Real Interest Parity Condition: Real interest rates accounting for anticipated currency depreciation inform investment decisions and currency switching.

  • Conclusion on PPP: Empirical evidence may not support absolute PPP while relative PPP is more applicable in many scenarios.