台灣近年來逐漸放寬外匯及金融的管制措施，使得台灣與國際間的資本移動愈趨活絡，而國際間利息套利活動的發生，使得各國的外匯與金融市場相互結合在一起，匯率與利率相互影響且其關係愈形密切，當資本可以自由移動時，每個時點兩國間利率的差異應等於預期的即期匯率變動率，此時無拋補利率平價說成立。 在實證方法上，本文擬以Djckey & Fuller(1979, 1981) ADF檢定，及Johansen (1988)最大概似共積估計法，對UIP進行實證分析。由於政府在各期間放寬資本管制的幅度不同，因此本文將實證期間區分成三個階段，分別為資本管制初步開放、逐步放寬與大幅開放三段期間，對台灣地區從事UIP的檢定。實證結果發現： (1)在資本管制初步開放的第一段期間，國內外資產報酬率不具有共整合關係，UIP不成立。 (2)在資本管制逐步放寬的第二段期間，國內外資產報酬率雖具有共整合關係，但是UIP不成立，表示資本移動性雖然較第一段期間提高，但仍有其限制性。 (3)在資本管制大幅開放的第三段期間，國內外資產報酬率不僅具有共整合關係，且UIP成立，表示在資本移動性相對大的階段，由本文實證檢定結果發現，UIP確實是成立的。 / In order to assess the degree of capital mobility of Taiwan in the sense of uncovered interest parity, this paper attempts to estimate the relationship between the return rate of domestic asset and the return rate of foreign asset with cointegration. Main conclusions are: In the first period(1985:9-1989:6), the return rate of domestic asset and foreign asset are not cointegrated by themselves. In the second period(1989:7-1993:12),a unique long- run relationship between these two variables can't be rejected. But the hypothesis of uncovered interest parity is rejected. These empirical evidences imply that capital is not freely mobile in the first and second period. However, in the third period(1994:l- 1998:3),with fewer financial regulations, a unique long-run relationship between these two variables can't be rejected. In addition, the coefficient of the return rate of foreign asset is insignificantly different from 1. It means that capital can moves most free in recent years.

本文主要在探討在較為短的時間段以及不同的金融環境之下，是否仍然能捕捉到匯率市場中主要解釋投組報酬變動的共同風險因子－平均超額報酬以及利差報酬。我們依據重要金融事件將全樣本分為八個子樣本；總共使用39種幣別並將1983年11月至2015年10月的遠期貼水由小到大排序後，依序建構六個投資組合。全文以美國投資者的觀點出發。結果顯示平均超額報酬無論是在長期或短期的時間段下，仍然為匯率市場中解釋匯率報酬變動的主要風險因子。然而，利差報酬則不然。在銀行危機期間，利差報酬與第二主要成分之相關係數皆為高度負相關。近期自2008年次貸危機開始，利差報酬與解釋投組變動的第二主要成分之相關係數也從先前的0.8~0.9降至-0.80.此結果顯示利差交易似乎在次貸危機之後有所轉變。此外利差風險因子無法有效的解釋動能報酬。 / This paper investigates whether or not the common risk factors, dollar and carry trade risk, in currency markets proposed by Lustig, Roussanov and Verdelhan (2011) will still exist even under a short-run period with a concern of different financial backgrounds. A split of full sample into eight subsamples with respect of financial events is made. A total of 39 currencies is used to build six portfolios on the basis of the forward discounts from November 1983 to October 2015. The whole paper is in the view of an American investor. The finding suggests that under both long-run and short-run period, the dollar return is always the common factor in currency markets. However, it is not the same case for the carry trade return. During bank crises, the carry trade return is strongly negative correlated with the second component. The carry trade return turns out to have a negative correlation with the second component during and after the subprime crisis, decreasing from 0.8~0.9 in the previous subsamples to -0.80. It indicates that the desirability of carry trade activities has changed since the subprime crisis. Besides, the carry trade risk has a little power to explain the variations of momentum returns.