Thursday, November 8, 2007

GUIDELINES FOR CORPORATE FORECASTING OF EXCHANGE RATES

Academics and practitioners have sought the determinants of exchange rate changes ever since there were currencies. Many students have learned about the balance of trade and how the more a country exports, the more demand there is for its currency, and so the stronger is its exchange rate. In practice, the story is a lot more complex. Research in the foreign exchange markets have come a long way since the days when international trade was thought to be the dominant factor determining the level of the exchange rate. Monetary variables, capital flows, rational expectations and portfolio balance are all now understood to factor into the determination of currencies in a floating exchange rate system. Many models have been developed to explain and to forecast exchange rates. No model has yet proved to be the definitive one, perhaps because the structure of the worlds economies and financial markets are undergoing such rapid evolution.
Corporations nevertheless avidly seek ways to predict currencies, in order to decide when and when not to hedge. The models they use are typically one or more of the following kinds: political event analysis, or fundamental, or technical.
Academic students of international finance, in contrast, find strong empirical support for the role of arbitrage in global financial markets, and for the view that exchange rates exhibit behavior that is characteristic of other speculative asset markets. Exchange rates react quickly to news. Rates are far more volatile than changes in underlying economic variables; they are moved by changing expectations, and hence are difficult to forecast. In a broad sense they are "efficient," but tests of efficiency face inherent obstacles in testing the precise nature of this efficiency directly.
The central "efficient market" model is the unbiased forward rate theory introduced earlier. It says that the forward rate equals the expected future level of the spot rate. Because the forward rate is a contractual price, it offers opportunities for speculative profits for those who correctly assess the future spot price relative to the current forward rate. Specifically, risk neutral players will seek to make a profit their forecast differs from the forward rate, so if there are enough such participants the forward rate will always be bid up or down until it equals the expected future spot. Because expectations of future spot rates are formed on the basis of presently available information (historical data) and an interpretation of its implication for the future, they tend to be subject to frequent and rapid revision. The actual future spot rate may therefore deviate markedly from the expectation embodied in the present forward rate for that maturity. The actual exchange rate may deviate from the expected by some random error.
As is indicated in Exhibit 8, in an efficient market the forecasting error will be distributed randomly, according to some probability distribution, with a mean equal to zero. An implication of this is that today's forecast, as represented by the forward rate, is equal to yesterday's forward plus some random amount. In other words, the forward rate itself follows a random walk. Another way of looking at these errors to consider them as speculative profits or losses: what you would gain or lose of you consistently bet against the forward rate. Can they be consistently positive or negative? A priori reasoning suggests that this should not be the case. Otherwise one would have to explain why consistent losers do not quit the market, or why consistent winners are not imitated by others or do not increase their volume of activity, thus causing adjustment of the forward rate in the direction of their expectation. Barring such explanation, one would expect that the forecast error is sometimes positive, sometimes negative, alternating in a random fashion, driven by unexpected events in the economic and political environment.
Rigorously tested academic models have cast doubt on the pure unbiased forward rate theory of efficiency, and demonstrated the presence of speculative profit opportunities (for example, by the use of "filter rules"). However it is also logical to suppose that speculators will bear foreign exchange risk only if they are compensated with a risk premium. Are the above-zero expected returns excessive in a risk-adjusted sense? Given the small size of the bias in the forward exchange market, and the magnitude of daily currency fluctuations, the answer is "probably not."
As a result of their finding that the foreign exchange markets are among the world's most efficient, academics argue the exchange rate forecasting by corporations, in the sense of trying to beat the market, plays a role only under very special circumstances. Indeed few firms are actively decide to commit real assets in order to take currency positions. Rather, they get involved with foreign currencies in the course of pursuing profits from the exploitation of a competitive advantage; rather than being based on currency expectations, this advantage is based on expertise in such areas as production, marketing, the organization of people, or other technical resources. If someone does have special expertise in forecasting foreign exchange rates, such skills can usually be put to use without incurring the risks and costs of committing funds to other than purely financial assets. Most finance managers of nonfinancial enterprises concentrate on producing and selling goods; they should find themselves acting as speculative foreign exchange traders only because of an occasional opportunity encountered in the course of their normal operations. Only when foreign exchange markets are systematically distorted by government controls on financial institutions do the operations of trading and manufacturing firms provide an opportunity to move funds and gain from purely financial transactions. Exhibit 9 offers a flowchart of criteria for forecasting and hedging decisions.
Forecasting exchange rate changes, however, is important for planning purposes. To the extent that all significant managerial tasks are concerned with the future, anticipated exchange rate changes are a major input into virtually all decisions of enterprises involved in and affected by international transactions. However, the task of forecasting foreign exchange rates for planning and decision-making purposes, with the purpose of determining the most likely exchange rate, is quite different from attempting to beat the market in order to derive speculative profits.
Expected exchange rate changes are revealed by market prices when rates are free to reach their competitive levels. Organized futures or forward markets provide inexpensive information regarding future exchange rates, using the best available data and judgment. Thus, whenever profit-seeking, well-informed traders can take positions, forward rates, prices of future contracts, and interest differentials for instruments of similar riskiness (but denominated in different currencies), provide good indicators of expected exchange rates. In this fashion, an input for corporate planning and decision-making is readily available in all currencies where there are no effective exchange controls. The advantage of such market-based rates over "in-house" forecasts is that they are both less expensive and more likely to be accurate. Market rates are determined by those who tend to have the best information and track-record; incompetent market participants lose money and are eliminated.
The nature of this market-based expected exchange rate should not lead to confusing notions about the accuracy of prediction. In speculative markets, all decisions are made on the basis of interpretation of past data; however, new information surfaces constantly. Therefore, market-based forecasts rarely will come true. The actual price of a currency will either be below or above the rate expected by the market. If the market knew which would be more likely, any predictive bias quickly would be corrected. Any predictable, economically meaningful bias would be corrected by the transactions of profit-seeking transactors.
The importance of market-based forecasts for a determination of the foreign exchange exposure of the firm is that of a benchmark against which the economic consequences of deviations must be measured. This can be put in the form of a concrete question: How will the expected net cash flow of the firm behave if the future spot exchange rate is not equal to the rate predicted by the market when commitments are made? The nature of this kind of forecast is completely different from trying to outguess the foreign exchange markets

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