Currency revaluation

In modern monetary policy, a devaluation is an official lowering of the value of a country's currency within a fixed exchange rate system, by which the monetary authority formally sets a new fixed rate with respect to a foreign reference currency or currency basket. In contrast, a depreciation is a decrease in a currency's value (relative to other major currency benchmarks) due to market forces under a floating exchange rate, not government or central bank policy actions.

A central bank maintains a fixed value of its currency by standing ready to buy or sell foreign currency with its own currency at a stated rate; a devaluation is a change in this stated rate that renders the foreign currency more expensive in terms of the home currency.

The opposite of devaluation, a change in the fixed rate making the foreign currency less expensive, is called a revaluation.

Related but distinct concepts include inflation, which is a market-determined decline in the value of the currency in terms of goods and services (related to its purchasing power). Altering the face value of a currency without reducing its exchange rate is a redenomination, not a devaluation or revaluation.

Devaluation is most often used in a situation where a currency has a defined value relative to the baseline. Historically, early currencies were typically coins struck from gold or silver by an issuing authority which certified the weight and purity of the precious metal. A government in need of money and short on precious metals might decrease the weight or purity of the coins without any announcement, or else decree that the new coins have equal value to the old, thus devaluing the currency.

Later, with the issuing of paper currency as opposed to coins, governments decreed them to be redeemable for gold or silver (a gold standard). Again, a government short on gold or silver might devalue by decreeing a reduction in the currency's redemption value, reducing the value of everyone's holdings.

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