Daniel Kurt 2016年8月1日
无论我们拿出纸币或者刷信用卡，我们参与的大多数日常交易都使用货币。事实上，货币是全世界经济的命脉。
要了解文明社会一直以来使用的货币，用其他代替品做比较是非常有用的。假设你做鞋为生，需要购买面包养活你的家人。你支付给面包师一双鞋获取一定数量的面包。但是事实是，面包师不需要鞋子。这时你就非常尴尬了，除非能找到附近需要鞋子的面包师。
货币解决了这一问题。它提供了一种普遍的价值储存手段，能够轻易的被社会其他成员接受。那个不需要鞋子的面包师可能需要一张桌子。通过接收货币，他能出售他的商品并且获得一个更加方便的向家具制造商的付款方式。
通常说来，货币使交易可以以更加快捷的速率发生，因为卖家可以更容易的找到愿意与他们做生意的买家。
货币还有其他重大优势。硬币和纸币相对更小的体积使他们更易于携带。设想一下一个玉米种植商随时带着一车玉米去买东西将是怎样的情形。
此外，硬币和纸币具有储存更长时间的优势，这一特点是很多商品不能具备的。例如，一个依赖直接交易的农民的资产可能在几周之后就会损坏。使用货币，他就能积累和储存他的财富。
形式多样
现在，人们很容易把货币与硬币和纸币联系在一起。然而，货币在历史上有过多种形式。在诸多早期社会中，某些大宗商品曾为支付的手段。例如在16世纪左右，阿兹特克人通常把可可豆作为货币代替直接货物交易。
然而，大宗商品在这方面有明显的缺点。由于其体积，他们很难从一个地方携带到另一个地方。而且在很多情况下，他们的使用寿命非常短。
这些成为了铸造货币是一个重要创新的原因。早在公元前2500年，埃及人创造了当作货币使用的金属环，而真实的硬币是在公元前700年左右在土耳其开始使用的。纸币直到唐代的中国才出现。
在近代，技术已经能支持完全不同的支付手段——电子货币。通过电报网络，西联在1871年完成了全球第一笔电子资金转账。随着大型计算机的出现，使人们能够进行借记卡和信用卡之间的转账，而不需要担心使用大量现金的麻烦。
货币的类型
因此，到底是什么形成了当代的美元或者日元的这种货币形式呢，是价值吗？与早期使用珍贵金属铸造的货币不同，大多数当今货币没有内在价值。但是它因两个原因保留了价值。
就代表货币来说，每个硬币或者纸币都能兑换成固定数量的商品。美元在二战之后也获得了这一功能，当时全世界的央行都可以使用30美元和美国政府兑换一盎司黄金。
然而，出于对美国黄金供应的担忧，尼克松总统取消了与世界各国的协议。通过放弃金本位制度，美元变成了所谓的“法定货币”。换句话说，它具有持有价值仅仅是因为人们相信其他人会接受它。
现在，全球大多数主要货币，包括欧元、英镑和日元，都是法定货币。
汇率政策
由于全球贸易的本质，贸易参与方也时常需要购买外国货币。政府有两个基本政策管理这一过程。第一个是提供一个固定汇率。
这里，政府把其货币与一个主要货币进行汇率绑定，例如美元或者欧元，在两种货币之间设定固定汇率。为了维持这个汇率，该国的央行需要购买或者卖出其绑定的货币。
设定固定汇率的主要目的是创造一个稳定的环境，尤其是一个国家的金融市场比世界其他地方更加复杂时。固定汇率能够增加投资者的信心。
然而，固定汇率也引起了近代的一部分货币危机。这是有可能的，例如，央行购买本国货币会导致货币估值过高。
与固定汇率相对的是浮动汇率。浮动汇率不是事先确定外国货币的价格，而是市场给出需要支付的成本。美国是使用浮动汇率的主要经济体之一。
在浮动汇率体制中，供求关系管理外国货币的价值。因此，货币数量的增加将降低货币的价值。而需求的增加将会增加货币的价值，使得货币更加昂贵。
虽然“强势”货币具有积极作用，它也有一些缺点。假设美元对日元升值。日本商人突然需要支付更多的成本购买美国商品，而这些成本将会被转移给消费者。这将使美国商品在海外的竞争力降低。
通货膨胀的影响
现在大多数主要经济体都在使用法定货币。因为法定货币不与实物资产挂钩，政府在财务困难时期可以自由的印刷更多的货币。这为解决问题提供了更大的灵活性，它也创造了超支的可能。
货币印刷太多最大的伤害是通货膨胀。流通的货币越多，其价值就越低。而适当的流通数量是无害的，货币不受控制的贬值将会大幅度削弱消费者的购买力。
如果年通胀达到5%，假设个人储蓄没有获得利息，那么其储蓄价值就会比一年前降低5%。自然就很难维持同样的生活水平。
总结
不管何种形式，所有货币的基本目的是相同的。它通过增加市场中各种商品的数量鼓励经济活动。同时，它能帮助消费者储存财富以满足长期需要。
How Currency Works
By Daniel Kurt | Updated August 1, 2016 — 12:02 PM EDT
Whether we pull out paper bills or swipe a credit card, most of the transactions we engage in daily use currency. Indeed, money is the lifeblood of economies around the world.
To understand why civilized societies have used currency throughout history, it’s useful to compare it to the alternative. Imagine you make shoes for a living and need to buy bread to feed your family. You approach the baker and offer a pair of shoes for a specific number of loaves. But as it turns out, he doesn’t need shoes at the moment. You’re out of luck unless you can find another baker - one who happens to be short on footwear - nearby.
Money alleviates this problem. It provides a universal store of value that can be readily used by other members of society. That same baker might need a table instead of shoes. By accepting currency, he can sell his goods and have a convenient way to pay the furniture maker.
In general, transactions can happen at a much quicker pace because sellers have an easier time finding a buyer with whom they want to do business.
There are other important benefits of money too. The relatively small size of coins and dollar bills makes them relatively simple to transport. Consider a corn grower who would have to load a cart full of food every time he needed to buy something.
Additionally, coins and paper have the advantage of lasting a long time, which is something that can’t be said for all commodities. A farmer who relies on direct trade, for example, may only have a few weeks before his assets spoil. With money, she can accumulate and store her wealth.
Various Forms
Today, it’s natural to associate currency with coins or paper notes. However, money has taken a number of different forms throughout history. In many early societies, certain commodities became a standard method of payment. Around the 16th century, for example, the Aztecs often used cocoa beans instead of trading goods directly.
However, commodities have clear drawbacks in this regard. Depending on their size, they can be hard to carry around from place to place. And in many cases, they have a limited shelf life.
These are some of the reasons why minted currency was an important innovation. As far back as 2500 B.C., Egyptians created metal rings that they used as money, and actual coins have been around since at least 700 B.C. when they were used by a society in modern-day Turkey. Paper money didn’t come about until the Tang Dynasty in China, which lasted from A.D. 618-907.
More recently, technology has enabled an entirely different form of payment: electronic currency. Using a telegraph network, Western Union (NYSE:WU) completed the first electronic money transfer way back in 1871. With the advent of mainframe computers, it became possible for banks to debit or credit each others’ accounts without the hassle of moving large sums of cash.
Types of Currency
So, what exactly gives our modern forms of currency – whether it’s an American dollar or a Japanese yen – value? Unlike early coins made of precious metals, most of what’s minted today doesn’t have much intrinsic value. However, it retains its worth for one of two reasons.
In the case of “representative money,” each coin or note can be exchanged for a fixed amount of a commodity. The dollar fell into this category in the years following World War II, when central banks around the world could pay the U.S. government $35 for an ounce of gold.
However, worries about a potential run on America’s gold supply led President Nixon to cancel this agreement with countries around the world. By leaving the gold standard, the dollar became what’s referred to as “fiat money.” In other words, it holds value simply because people have faith that other parties will accept it.
Today, most of the major currencies around the world – including the euro, British pound and yen – fall into this category.
Exchange-Rate Policies
Because of the global nature of trade, parties often need to acquire foreign currencies as well. Governments have two basic policy choices when it comes to managing this process. The first is to offer a fixed exchange rate.
Here, the government pegs its own currency to one of the major world currencies, such as the American dollar or the euro, and sets a firm exchange rate between the two denominations. To preserve the local exchange rate, the nation’s central bank either buys or sells the currency to which it is pegged.
The main goal of a fixed exchange rate is to create a sense of stability, especially when a nation's financial markets are less sophisticated than those in other parts of the world. Investors gain confidence by knowing the exact amount of the pegged currency they can acquire, if they so desire.
However, fixed exchange rates have also played a part in numerous currency crises in recent history. This can happen, for instance, when the purchase of local currency by the central bank leads to its overvaluation.
The alternative to this system is letting the currency float. Instead of pre-determining the price of a foreign currency, the market dictates what the cost will be. The United States is just one of the major economies that uses a floating exchange rate.
In a floating system, the rules of supply and demand govern a foreign currency's price. Therefore, an increase in the amount of money will make the denomination cheaper for foreign investors. And an increase in demand will strengthen the currency – that is, make it more expensive.
While a “strong” currency has positive connotations, there are drawbacks. Suppose that the dollar gained value against the yen. Suddenly, Japanese businesses would have to pay more to acquire American-made goods, likely passing their costs on to consumers. This makes U.S. products less competitive in overseas markets.
The Impact of Inflation
Most of the major economies around the world now use fiat currencies. Since they’re not linked to a physical asset, governments have the freedom to print additional money in times of financial trouble. While this provides greater flexibility to address challenges, it also creates the opportunity to overspend.
The biggest hazard of printing too much money is hyperinflation. With more of the currency in circulation, each unit becomes worth less. While modest amounts of inflation are relatively harmless, uncontrolled devaluation can dramatically erode the purchasing power of consumers.
If inflation reaches 5% annually, each individual’s savings – assuming it doesn’t accrue substantial interest – is worth 5% less than it was the previous year. Naturally, it becomes harder to maintain the same standard of living.
For this reason, central banks in developed countries usually try to keep inflation under control by indirectly taking money out of circulation when the currency loses too much value.
因为这个原因，发展中国家的中央银行通常在流通货币过多时减少流通从而控制通货膨胀。
The Bottom Line
Regardless of the form it takes, all money has the same basic goals. It helps encourage economic activity by increasing the market for various goods. And it enables consumers to store wealth and therefore address long-term needs.
本文翻译由兄弟财经提供
文章来源：http://www.investopedia.com/articles/investing/092413/how-currency-works.asp