汇率变化的决定性因素分析-指导风险管理论文

The Determination of the Exchange Rate汇率变化的决定性因素

Exchange rates defined汇率定义

An exchange rate is the price of one currency in terms of another, or a number of currencies.
汇率是从另一个方面对一种货币或多种货币的价格的定义。
Assuch, it is determined in the market place for currencies, and moves up or down in accordance withrelative forces of demand and supply. In this case the market place is no longer physical, sincecurrency transactions are these days conducted on dealers screens. This, in turn, means that anyonecan deal in currencies at any time of the day or night anywhere in the world. Not surprisingly,exchange rates are, as a consequence, constantly fluctuating as dealers seek to profit from very smallmovements in rates.http://www.ukassignment.org/fxgllw/

Most transactions are for immediate delivery at the current price on the ‘spot’ market. Such ratesare therefore known as spot rates. This is the measure of exchange rates we are all most familiarwith; current rates which change during the day of trading. The foreign exchange market typicallyquotes two prices for spot exchange rates, the purchasing and selling price. To profit from trading inforeign exchange, banks bid to buy foreign exchange at lower rates and sell it at higher rates, thedifference being known as the spread. Thus, if you sold currency to a bank and immediately re-purchased it from them, aside from the commission charged for the service, the price you wouldreceive from the bank for your currency would be lower than the level it then charged for the sameamount of currency you subsequently purchased. The spread compensates for the anticipated risk thebank associates with holding the currency. Thus, for a relatively ‘safe’ currency such as theDeutschmark or US dollar, the spread will be relatively small. However, for a risky currency like theSouth African Rand during the political disturbances caused by apartheid, the spread would have beenrelatively larger to compensate for the increased risk associated with holding the currency.然而，对于有风险的货币，如南非兰特在政治动乱所造成的种族隔离的行为，相对增加持有的这个地区的货币，会出现较大的风险。

The foreign exchange market is a relatively pure type of market in that price information is readilyavailable, relatively inexpensively accessed through the electronic media, whilst currencies arehomogenous goods - one dollar is the same as another dollar. Thus, it is easy to compare prices indifferent markets and it is expected that they will be equal world-wide. For example, a rate of ￡1=$2.5dollars in London should be exactly replicated in New York and Tokyo. However, if this did notoccur, for example with the price ￡1 = $2.6 in Amsterdam and ￡1 = $2.4 in London, economic theorypredicts that arbitrage will occur to equalise the exchange rates to the international rate. This refersto the fact that discontinuous pricing of homogenous goods leads to profit opportunities for those whocan buy cheaply in one market and sell more expensively in another, thereby equalising the prices inboth. In the example given here, profit can be made by purchasing dollars with sterling in Amsterdam,thereby receiving $2.6 for every pound, and selling dollars in London for dollars, thereby only havingto spend $2.4 dollars for every pound. Thus, arbitrageurs will make a profit of $0.2 dollars on everytransaction, which is a considerable amount if trading encompasses millions of currency units. Thus,the demand for dollars rises in Amsterdam and falls in London, causing the exchange rates to shifttowards a market equilibrium rate of ￡1 = $2.5.Trading in foreign currencies need not occur for immediate use, but might be required for futurepurchases of goods and services. Therefore, a futures market exists where traders in a currency agreea price today for delivery of the currency at some future date. This is a valuable option for firms engaged in international trade, since they can hedge against future changes in currency values whichcould affect the eventual profitability of a transaction which has to be agreed in advance. Forexample, a car dealer in the UK may wish to purchase a German car which will take six weeks todeliver. The dealer has to trade sterling for deutschmarks to purchase the car but, whilst the moneywill not be paid until the car arrives, the price will be agreed in the contract signed in advance. Thus,both parties to the agreement wish to avoid exchange rate changes which will reduce or eliminatetheir profit margins once the money changes hands in six weeks time. Consequently, both canpurchase options on the future price of sterling and deutschmarks to eliminate the risk. The futuresmarket enables the UK importer to agree to purchase 100,000 deutschmarks at the exchange rate ￡1 =DM2.5 in six weeks time so the importer can avoid sterling weakening against the dollar and finding afuture situation where ￡1 only buys DM2 deutschmarks, meaning the importer has to spend morepounds to meet the valuation of the car priced in deutschmarks. This trade is possible since othertraders are willing to provide the importer with DM2.5 deutschmarks for every pound because theybelieve sterling will strengthen to be worth DM3, therefore if they guess correctly they will make aprofit on the deal. Obviously only one party to the transaction can be correct, but the fact that both arewilling to make this agreement, either to hedge against future prices or to profit by speculation,enables the market to function. The market price consequently reflects the expected price of sterlingin the future and not the current price. Forward transactions are not cost-less transactions, but occurbecause traders have differential risk preferences and are more, or less, risk averse.

Measures of the exchange rate针对汇率变化采取的措施

The basic and most simplistic measure is the sterling foreign exchange rate (R). This is the cost of aunit of foreign exchange in terms of domestic currency. If R rises, this implies a fall in the value ofsterling.最基本和最简单的措施是针对英镑的汇率（R）。这是针对国内单位货币的成本外汇的一种计算方式。如果R上升，这意味着英镑的价值下跌。

Measuring exchange rates in terms of individual currencies does, however, have drawbacks. In thefirst place, history has shown that such rates can be volatile. However, this volatility is morepronounced in certain cases and individual rates may not move in parallel in the same direction,but at different speeds and perhaps also in opposite directions. In order to adjust for this, analternative is to measure is that of exchange rate indexes which are constructed to measure theaverage value of a currency relative to several other currencies. This typically takes the form of abasket of currencies which includes all those of any significance in terms of UK and, by implication,of world trade.这通常需要一篮子货币政策，这些其中包括所有那些在英国甚至是世界内的所有的贸易的形式。