Currency
A currency is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes, coins, electronic balances in bank accounts, and central bank digital currencies. A more general definition is that a currency is a system of money in common use within a specific environment over time, especially for people in a nation state. Under this definition, the Pound sterling, euro, Japanese yen, and U.S. dollars are examples of fiat currencies. Currencies may act as stores of value and be traded between nations in foreign exchange markets, which determine the relative values of the different currencies. Currencies in this sense are either chosen by users or decreed by governments, and each type has limited boundaries of acceptance; i.e., legal tender laws may require a particular unit of account for payments to government agencies.
Other definitions of the term currency appear in the respective synonymous articles: banknote, coin, and money. This article uses the definition which focuses on the currency systems of countries.
One can classify currencies into three monetary systems: fiat money, commodity money, and representative money, depending on what guarantees a currency's value. Some currencies function as legal tender in certain jurisdictions, or for specific purposes, such as payment to a government, or government agencies. Others simply get traded for their economic value.
History
Early currency
Originally, currency was a form of receipt, representing grain stored in temple granaries in Sumer in ancient Mesopotamia and in Ancient Egypt. In this first stage of currency, metals were used as symbols to represent value stored in the form of commodities. This formed the basis of trade in the Fertile Crescent for over 1500 years. However, the collapse of the Near Eastern trading system pointed to a flaw: in an era where there was no place that was safe to store value, the value of a circulating medium could only be as sound as the forces that defended that store. A trade could only reach as far as the credibility of that military. By the late Bronze Age, however, a series of treaties had established safe passage for merchants around the Eastern Mediterranean, spreading from Minoan Crete and Mycenae in the northwest to Elam and Bahrain in the southeast. It is not known what was used as a currency for these exchanges, but it is thought that oxhide-shaped ingots of copper, produced in Cyprus, may have functioned as a currency.It is thought that the increase in piracy and raiding associated with the Bronze Age collapse, possibly produced by the Peoples of the Sea, brought the trading system of oxhide ingots to an end. It was only the recovery of Phoenician trade in the 10th and 9th centuries BC that led to a return to prosperity, and the appearance of real coinage, possibly first in Anatolia with Croesus of Lydia and subsequently with the Greeks and Persians. In Africa, many forms of value store have been used, including beads, ingots, ivory, various forms of weapons, livestock, the manilla currency, shell money, and ochre and other earth oxides. The manilla rings of West Africa were one of the currencies used from the 15th century onwards to sell slaves. African currency is still notable for its variety, and in many places, various forms of barter still apply.
Coinage
The prevalence of metal coins possibly led to the metal itself being the store of value: first copper, then both silver and gold, and at one point also bronze. Today other non-precious metals are used for coins. Metals were mined, weighed, and stamped into coins. This was to assure the individual accepting the coin that they were getting a certain known weight of precious metal. Coins could be counterfeited, but the existence of standard coins also created a new unit of account, which helped lead to banking. Archimedes' principle provided the next link: coins could now be easily tested for their fine weight of the metal, and thus the value of a coin could be determined, even if it had been shaved, debased or otherwise tampered with.Most major economies using coinage had several tiers of coins of different values, made of copper, silver, and gold. Gold coins were the most valuable and were used for large purchases, payment of the military, and backing of state activities. Units of account were often defined as the value of a particular type of gold coin. Silver coins were used for midsized transactions, and sometimes also defined a unit of account, while coins of copper or silver, or some mixture of them, might be used for everyday transactions. This system had been used in ancient India since the time of the Mahajanapadas. The exact ratios between the values of the three metals varied greatly between different eras and places; for example, the opening of silver mines in the Harz mountains of central Europe made silver relatively less valuable, as did the flood of New World silver after the Spanish conquests. However, the rarity of gold consistently made it more valuable than silver, and likewise silver was consistently worth more than copper.
Paper money
In premodern China, the need for lending and for a medium of exchange that was less physically cumbersome than large numbers of copper coins led to the introduction of paper money, i.e. banknotes. Their introduction was a gradual process that lasted from the late Tang dynasty into the Song dynasty. It began as a means for merchants to exchange heavy coinage for receipts of deposit issued as promissory notes by wholesalers' shops. These notes were valid for temporary use in a small regional territory. In the 10th century, the Song dynasty government began to circulate these notes amongst the traders in its monopolized salt industry. The Song government granted several shops the right to issue banknotes, and in the early 12th century the government finally took over these shops to produce state-issued currency. Yet the banknotes issued were still only locally and temporarily valid: it was not until the mid 13th century that a standard and uniform government issue of paper money became an acceptable nationwide currency. The already widespread methods of woodblock printing and then Bi Sheng's movable type printing by the 11th century were the impetus for the mass production of paper money in premodern China.At around the same time in the medieval Islamic world, a vigorous monetary economy was created during the 7th–12th centuries on the basis of the expanding levels of circulation of a stable high-value currency. Innovations introduced by Muslim economists, traders and merchants include the earliest uses of credit, cheques, promissory notes, savings accounts, transaction accounts, loaning, trusts, exchange rates, the transfer of credit and debt, and banking institutions for loans and deposits.
In Europe, paper currency was first introduced on a regular basis in Sweden in 1661. As Sweden was rich in copper, many copper coins were in circulation, but its relatively low value necessitated extraordinarily big coins, often weighing several kilograms.
The advantages of paper currency were numerous: it reduced the need to transport gold and silver, which was risky; it facilitated loans of gold or silver at interest, since the underlying specie never left the possession of the lender until someone else redeemed the note; and it allowed a division of currency into credit- and specie-backed forms. It enabled the sale of investment in joint-stock companies and the redemption of those shares in a paper.
But there were also disadvantages. First, since a note has no intrinsic value, there was nothing to stop issuing authorities from printing more notes than they had specie to back them with. Second, because this increased the money supply, it increased inflationary pressures, a fact observed by David Hume in the 18th century. Thus paper money would often lead to an inflationary bubble, which could collapse if people began demanding hard money, causing the demand for paper notes to fall to zero. The printing of paper money was also associated with wars, and financing of wars, and therefore regarded as part of maintaining a standing army. For these reasons, paper currency was held in suspicion and hostility in Europe and America. It was also addictive since the speculative profits of trade and capital creation were quite large. Major nations established mints to print money and mint coins, and branches of their treasury to collect taxes and hold gold and silver stock.
At that time, both silver and gold were considered a legal tender and accepted by governments for taxes. However, the instability in the exchange rate between the two grew over the course of the 19th century, with the increases both in the supply of these metals, particularly silver, and in trade. The parallel use of both metals is called bimetallism, and the attempt to create a bimetallic standard where both gold and silver backed currency remained in circulation occupied the efforts of inflationists. Governments at this point could use currency as an instrument of policy, printing paper currency such as the United States greenback, to pay for military expenditures. They could also set the terms at which they would redeem notes for specie, by limiting the amount of purchase, or the minimum amount that could be redeemed.
By 1900, most of the industrializing nations were on some form of gold standard, with paper notes and silver coins constituting the circulating medium. Private banks and governments across the world followed Gresham's law: keeping the gold and silver they received but paying out in notes. This did not happen all around the world at the same time, but occurred sporadically, generally in times of war or financial crisis, beginning in the early 20th century and continuing across the world until the late 20th century, when the regime of floating fiat currencies came into force. One of the last countries to break away from the gold standard was the United States in 1971, an action which was known as the Nixon shock. No country has an enforceable gold standard or silver standard currency system.