Currency substitution is the use of a foreign currency in parallel to or instead of a domestic currency.
Currency substitution can be full or partial. Full currency substitution can occur after a major economic crisis, such as in Ecuador. Some small economies, for whom it is impractical to maintain an independent currency, use the currencies of their larger neighbours; for example, Liechtenstein uses the Swiss franc.
An exchange rate regime is a way a monetary authority of a country or currency union manages the currency about other currencies and the foreign exchange market. It is closely related to monetary policy and the two are generally dependent on many of the same factors, such as economic scale and openness, inflation rate, the elasticity of the labor market, financial market development, and capital mobility.
There is no correct or optimal exchange rate. However, the exchange rate has distributional consequences with winners and losers in the domestic economy. Exporters and importers lose with currency appreciation while consumers and domestic oriented industries benefit from currency appreciation. A currency depreciation has the opposite effect.
In macroeconomics and economic policy, a floating exchange rate (also known as a fluctuating or flexible exchange rate) is a type of exchange rate regime in which a currency's value is allowed to fluctuate in response to international events affecting exchange rates. A currency that uses a floating exchange rate is known as a floating currency. In contrast, a fixed currency is one where its value is specified in terms of material goods, another currency, or a group of other currencies. The idea of a fixed currency is to reduce currency fluctuations.
In the modern world, most of the world's currencies are floating, and include the majority of the most widely traded currencies: the United States dollar, the euro, the Japanese yen, the pound sterling, or the Australian dollar. However, even with floating currencies, central banks sometimes participate in markets to attempt to influence the value of floating exchange rates. The Canadian dollar has not seen interference by the Canadian national bank with its price since September 1998. The US dollar also sees very little change of its foreign reserves.
In economics, hyperinflation is a very high and typically accelerating inflation. It quickly erodes the real value of the local currency, as the prices of all goods increase. This causes people to minimize their holdings in that currency as they usually switch to more stable foreign currencies. Effective capital controls and currency substitution ("dollarization") are the orthodox solutions to ending short-term hyperinflation; however, there are significant social and economic costs to these policies. Ineffective implementations of these solutions often exacerbate the situation. Many governments choose to attempt to solve structural issues without resorting to those solutions, with the goal of bringing inflation down slowly while minimizing social costs of further economic shocks; however, this can lead to a prolonged period of high inflation.
Unlike low inflation, where the process of rising prices is protracted and not generally noticeable except by studying past market prices, hyperinflation sees a rapid and continuing increase in nominal prices, the nominal cost of goods, and in the supply of currency. Typically, however, the general price level rises even more rapidly than the money supply as people try ridding themselves of the devaluing currency as quickly as possible. As this happens, the real stock of money (i.e., the amount of circulating money divided by the price level) decreases considerably.