1. Historical Context
In the 16th century, the English merchant and financier Sir Thomas Gresham observed a peculiar behavior in the circulation of gold and silver coins in the London market.
2. The Breakdown Event
The British crown had devalued the metal content of legal tender silver coins to finance wars, issuing new coins mixed with cheap metals (copper). Gresham noticed that the population kept, hoarded and melted the old pure silver coins (good money), and preferred to actively spend the new coins adulterated with copper (bad money) in taverns and everyday shops. Since both currencies had the same legal value decreed by the king, people removed the valuable currency from circulation, leaving only the depreciated currency on the market.
3. Global Economic Impact
Gresham's principle demonstrated that government price controls and fictitious exchange rate parities are unsustainable in the face of the rational behavior of economic agents, who always try to preserve their real purchasing power.
Key Financial Lesson (Psychology of Money)
When the government decrees an artificial parity between two currencies that have a different real value in the free market, the currency with lower real value (bad money) will circulate as a daily medium of exchange, while the valuable one (good money) will be hoarded.
4. Practical Case or Real Life Example
In modern countries with strict exchange controls and severe inflation (such as Venezuela or Argentina), citizens hoard stable US dollars (good money) and immediately dump their weak local pesos or bolivars (bad money).