Exchange Rate Determination: Gold Standard vs. Paper Currency Standard

1. Introduction: The Evolution of Exchange Rate Regimes

The mechanism through which foreign currencies are valued has transformed across distinct monetary epochs in global financial history:

2. Determination Under the Classical Gold Standard

Under the Classical Gold Standard, a country’s monetary authority legally guaranteed the unconditional convertibility of its domestic currency banknotes into a fixed, statutory weight of pure gold, and permitted the unrestricted import and export of physical gold bullion.

A. The Mint Par of Exchange (Mint Parity)

The fundamental equilibrium exchange rate between any two currencies under the Gold Standard was determined by comparing the statutory gold content of one unit of each currency:

Mint Par of Exchange Formula:
Mint Par = (Weight of pure gold in Currency A) / (Weight of pure gold in Currency B)

Historical Numerical Illustration:

• Prior to World War I:
  • 1 British Sovereign (GBP): Contained 113.0016 grains of pure gold.
  • 1 US Dollar (USD): Contained 23.2200 grains of pure gold.
• The Mint Par of Exchange between the British Pound and US Dollar was:

  Mint Par (GBP / USD) = 113.0016 / 23.2200 = 4.8665 USD per 1 GBP

B. Gold Points (Specie Points) & Boundaries of Exchange Rate Movement

Could the actual market exchange rate deviate from the Mint Par of 4.8665 USD?
Yes, but only within extremely narrow limits! The market exchange rate could never deviate beyond the cost of physically packing, insuring, and shipping gold across the Atlantic Ocean (called the Cost of Gold Transport / Specie Shipping Cost).

These limits were defined as the Gold Export Point and the Gold Import Point:

3. Determination Under the Inconvertible Paper Currency Standard

Following the collapse of the Gold Standard and the abandonment of the Bretton Woods system in 1971–1973, the modern world transitioned to an Inconvertible Paper Currency Standard (Fiat Money).

Under this standard:

• Currencies possess no statutory metallic gold backing and cannot be redeemed for precious metals at the central bank.
• The external value of a fiat currency is not fixed by law; it is determined by internal purchasing power and international market supply and demand.

Core Theories Explaining Paper Currency Exchange Rates:

1. Purchasing Power Parity (PPP) Theory:
   Formulated by Gustav Cassel. The exchange rate between two paper currencies is fundamentally determined by the ratio of their internal purchasing powers (price levels).
2. Balance of Payments (Demand & Supply) Theory:
   The modern equilibrium exchange rate is determined at the precise intersection of the Demand for Foreign Exchange (arising from imports and capital outflows) and the Supply of Foreign Exchange (arising from exports and capital inflows).

4. Analytical Comparison: Gold Standard vs. Paper Standard