The current intellectual climate regarding economics seems to be at an agreement regarding the theory of uncovered interest parity and its unreliability within real life application. The purpose of this thesis is to test how the theory holds over periods with varying economic stability, both using a short- and long-horizon test in order to establish the usefulness of uncovered interest parity as a predictor for exchange rate movements. The short-horizon test will utilize the interbank offering rate, and the long-horizon test the yield to maturity of government 10-year benchmark bonds as the interest rate. The sample period is 2000 to 2018, covering the financial crisis of 2007. We will focus on three different time periods: pre-crisis, crisis and post-crisis. We will use ordinary least squares (OLS) regression and an extreme sampling. From the regressions we conclude that most of the time periods move against the uncovered interest parity, where only the crisis period is in line with the theory. The extreme sampling supports this result, as larger interest differentials provide the rational expectations with more predictive power of the future spot exchange rate.

在古典理性預期模型中，理性的投資者會蒐集並利用各種相關訊息來幫助其做最適的投資行為。然而市場價格也是訊息來源之一。在效率市場中，價格完全透露出訊息，則無人會有蒐集訊息的動機；若市場有干擾，價格無法顯露出所有相關訊息，私人訊息便有價值。因此，價格資訊性的高低，會影響到私人訊息對投資的重要性。其次，訊息若要能幫助投資者獲得套利利潤，仍須假設投資者必須能夠持有資產一直至資產價值實現為止。顯然的，短期投資者並不符合此一假設。我們相信在通常情況下，長期投資者會比短期投資者更有動機去成為消息靈通者，而且短期投資者對訊息處理的態度有許多特性迴異於古典模型的投資者，他們的存在對市場價格資訊性也會有相當程度的衝擊。本文基於上述想法，利用干擾不對稱訊息下之多期理性預期模型，假設市場中有長期與短期投資者，來探討影響價格資訊性之各項因素及短期投資者之行為特性。

The characteristics of interest rate differentials’ relationships with the change in nominal exchange rates are here investigated from the small open economy Sweden’s pointof view. We assume rational expectations and risk neutrality. However, these are solelysufficient but not necessary conditions. The only necessary condition is that the deviationsfrom rational expectations and risk neutrality are uncorrelated with the interestrate differential (Chinn and Meredith 2004, p. 412). We find no evidence for the interestrate differentials to be unbiased predictors of the percentage change in nominalexchange rates. With 3- and 6-month maturity interest rates, the signs are positivealthough not statistically different from zero.

This thesis consists of three essays on the behavior of corporate insiders and the optimal regulation of insider trading. The first of these three essays examines the welfare effects of insider trading and its attributes as an executive compensation mechanism; in addition, an optimal regulation of insider trading in the light of the model is proposed. The second essay analyzes another facet of insider trading: whether insiders can be a source of liquidity and act as traders of last resort on their companies' stock; moreover, the effects of transactions by insiders and by the company itself on the distribution of stocks returns are compared empirically. Finally, the topic of the third essays is the dynamics of insiders' holdings, and how these dynamics are a function of the number of large shareholders in the firm; the conclusions are empirically tested for Real Estate Investment Trusts.Aquesta tesi conté tres assajos sobre el comportament dels agents corporatius y la regulació de la compravenda d'accions amb informació privilegiada. El primer examina l'efecte de la negociació amb informació privilegiada y la seva utilitat com a mecanisme de compensació; es proposa una regulació de la negociació amb informació privilegiada. El segon assaig analitza si els agents corporatius són una font de liquiditat y actuen com a comerciants d'últim recurs per a les accions de la seva companyia; també es comparen empíricament els efectes de la negociació per part dels actors corporatius amb els de la negociació per part de les mateixes empreses en la distribució dels rendiments de les accions. L'últim assaig estudia la dinàmica de les carteres d'aquest actors en accions de les seves pròpies empreses, i com aquesta dinàmica es funció del nombre d'actors corporatius a l'empresa; les conclusions es testegen empíricament per a fons d'inversió immobiliària.