英语论文网

2.2.2.4 汇率波动和贸易——2.2.2.4 Exchange Rate Volatility and trade
 
基本的贸易不确定性模型——uncertainty trade models
 
The traditional models examine the behaviour of undiversified firms and are based on the assumption that the firm's profitability is linked directly and unambiguously to the movement in one bilateral exchange rate. The variability of that exchange rate is assumed to measure the risk to the firm in conducting trade. Therefore in the simplest model, higher exchange rate risk is assumed to have a negative impact on trade, since it creates uncertainty with respect to profits of firms' exports and, hence, lead risk-averse exporters to reduce their supply of exports, an effect that increases with the degree of risk aversion.
 
An example provided by Clark(1973) can be used to illustrate the concept of how exchange rate volatility can affect the level of a firm's exports. Clark develops a model of a firm operating under competitive conditions. In the simplest version described, it is assumed that the firm produces a homogeneous commodity which is sold entirely in a foreign market. The firm has no market power and its does not import any inputs and the production decision is taken before observing exchange rate volatility, therefore output is constant over the planning horizon. Also the price of the exported good in foreign currency is an exogenous variable. The firm in paid in foreign currency and hedging possibilities such as forwards or futures market is very limited. The firm converts its proceeds from exports at the current exchange rates. Given the above assumptions, variability in the exchange rate will affect the firm's level of profits since output cannot be altered in response to a favourable or unfavourable move in the profitability of exports due to exchange rate movements and there are also limited hedging techniques. Therefore uncertainty about future exchange rates translates into uncertainty on future export receipts in domestic currency. This uncertainty will be considered by the firm when deciding on the level of exports. The firm maximises the expected value of utility which is assumed to take the following quadratic form: U(p)= a p +b p2
 
Under conditions of risk aversion (b < 0), the first-order condition requires that marginal revenue exceed marginal cost. The firm must be compensated for the exchange risk it bears and thus the supple curve shifts towards the left and the volume of production and trade is reduced. A risk-averse firm tries to reduce its exposure to risk by reducing sales, hence both expected profits and the variance of profits decline, but expected utility increases. If inputs were imported, the contraction in the supply of exports would be smaller. The variance in profits would not rise in proportion to the increase in the variance of the exchange rate. Only in the extreme case of perfect correlation between revenues and costs in domestic currency terms would greater variability have no effect on the variance of profits. Ethier (1973) also supported this view and shows that, if traders were uncertain as to how the exchange rate affects their firms' revenue, the volume of trade will be reduced.
 
However the above analysis is based on a number of restrictive assumptions. Other re本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。