運輸成本在不同匯率體制下之效果分析

TO UNDERSTAND THE EFFECTS OF TRANSPORTATION COSTS UNDER DIFFERENT EXCHANGE RATE REGIMES

本文採用「新開放總體經濟學」作為分析基礎，探究一個存在運輸成本的經濟體系，當面臨國外貨幣面衝擊時，對本國消費波動、期望消費以及福利水準的影響。根據理論推導與數值模擬結果，本文發現外國貨幣面干擾對本國消費的影響端視運輸成本、市場取價、家鄉偏好及資本移動程度等參數的大小而定，其中，隨著運輸成本提高，若一國施行浮動匯率體制，且兩國商品皆按照生產者貨幣定價或皆以外國貨幣定價，則國外貨幣面衝擊引起本國消費波動程度愈有可能大於固定匯率制度體制；其次，在兩國商品皆按照生產者貨幣定價或皆以外國貨幣定價下之浮動匯率體制，以及固定匯率體制，期望消費水準將隨著運輸成本的提高而下降；最後，不論是浮動匯率體制（包括生產者貨幣定價、消費者貨幣定價、外幣本位制、本幣本位制模型）或固定匯率體制，福利水準都會隨著運輸成本的提高而下降。

In this paper, we follow the New Open Economy Macroeconomics to investigate how transportation costs affect the consumption volatility, expected level of consumption, and the welfare performance under alternative exchange-rate regimes for a country facing foreign monetary shocks. According to the theoretical derivation and numerical simulation, we find that the parameters of transportation costs, pricing to market, the degree of home bias and capital mobility are the key factors that affect the effect of a foreign monetary disturbance on domestic consumption and welfare level. From the aspect of the role of transportation costs, the results show that the consumption volatility under floating exchange rate with producer-currency pricing (PCP model for short) and with foreign currency standard (FCS model for short) will be probability greater than that in fixed exchange rate regime (FER model for short) by the higher cost of transport. And, we can also find that an increase in transportation costs will lead to a decrease of expected consumption under PCP, FCS and FER models. Finally, the welfare level will decrease under alterative exchange rate regime with the higher transportation costs.