Currency carry trade is an investment strategy that recently started gaining a lot of interest not only among investors and financial institutions but also academically. One of the underlying theoretical assumptions regarding the mechanisms of the foreign exchange market, the Uncovered Interest Parity has frequently been disproved in practice which has led to the conclusion that carry trade is profitable in practice. The function of a carry trade strategy is that a short position is taken in a low interest rate currency to finance a long position in another currency offering higher yields. This thesis is adding to the existing literature that is explaining the characteristics of currency carry trade but is adopting a different approach than most other recent researches that has focused on identifying especially risk factors. Gold as a financial asset has also received much attention largely due to its, contrarily to other asset classes, low dependence on macroeconomic factors. This makes gold desirable to diversify portfolios and decreasing overall risks. By investigating how the returns of currency carry trades and gold relates to each other an increased understanding in how carry trades can be beneficially included in managing portfolios are developed. Looking at a currency carry trade index, Deutsche Bank’s G10 Currency Future Harvest index, and the development of the gold price at the London bullion market for the 20 year period of 1993-2013 this research is exploring correlation, mean and volatility spillover effects. Spearman’s correlation, Vector Autoregression and a diagonal BEKK GARCH model are employed to test these effects. It also investigates if gold possesses hedge, diversifier and safe haven characteristics when combined with carry trades as it has been found to do with stock markets. This is determined by a regression analysis and supplemented by a portfolio simulation. This thesis found that there is a low positive correlation between the returns of gold and currency carry trades and that there is spillover effects as well between the two in both returns and volatility. This in addition to the regression analysis and portfolio analysis determined that there are diversification benefits by adding gold to a portfolio consisting of currency carry trade in the form of higher risk adjusted returns. However special caution has to be taken to the spillover effects as these complicate the relationship between the returns of the two variables and especially the volatility spillover effects slightly decreases the potential diversification benefit. The regression analysis concluded that gold work as a diversifier for carry trade but could not determine if it also exhibited hedge or safe haven characteristics. These findings pushes the existing understanding of carry trades forward and adds to focus of matching carry trades within a portfolio which could have implications to more efficiently match risks and returns by combining several asset classes in portfolio management.

Cette thèse étudie deux grandes problématiques économiques étant étroitement liées. D’une part, il est question d’analyser à quelles conditions les taux de change présentent des relations de long terme communes. D’autre part, une analyse en profondeur concernant les investissements sur devises connus sous le terme anglais de « carry trades » est proposée. Le taux de change étant un des déterminants du rendement de ces investissements, le lien entre les deux problématiques apparaît clairement. Ces problématiques sont traitées à travers la mobilisation d’outils théoriques et empiriques. Ce travail aboutit à plusieurs conclusions. Concernant les mouvements communs de long terme entre les taux de change, ils dépendent du degré d’intégration des économies ainsi que de la similarité de leurs politiques monétaires. Concernant les investissements sur devises, cette thèse démontre que les banques centrales des petites économies ouvertes ont tout intérêt à fixer une cible d’inflation ainsi qu’une cible d’afflux de capitaux afin d’éviter l’effet déstabilisateur des « carry trades ». Cette politique sera efficace uniquement si la banque centrale est transparente concernant ses cibles de long terme. Pour finir, après la crise financière de 2008, la banque centrale Néo-Zélandaise a changé de comportement vis-à-vis des « carry trades » en provenance du Japon. En effet, après la crise, la banque centrale y a répondu de manière à stabiliser l’économie. Cependant, les investissements en provenance des Etats-Unis sont toujours déstabilisateurs pour l’économie Néo-Zélandaise, surtout lorsque les Etats-Unis utilisent une politique d’assouplissement quantitatif. / This thesis investigates two main issues in economics. On the one hand, we investigate under which conditions cointegration between exchange rates is likely to appear. On the other hand, this thesis proposes to investigate how carry trades affect small open economies. Given that the exchange rate is a main determinant of carry trades’ returns, these two topics are obviously linked. These two issues are investigated both through theoretical and empirical tools. Concerning long run comovements between exchange rates, this thesis reveals that they depend on the degree of linkages between two economies and on the way central banks set their monetary policies. Concerning carry trades, this work sheds light on the fact that small open economies central banks should have both an inflation and a capital inflows target to suppress the destabilizing effect of carry trades. Moreover, such a policy would be efficient only if the central banks are transparent concerning their long run targets. Finally, in this thesis we show that the Reserve Bank of New Zealand (RBNZ) has changed its reaction to Japan-sourced carry trades after the 2008 global financial crisis (GFC). Indeed, after the GFC, the RBNZ responded in a stabilizing way to Japan-sourced carry trades. However, after the GFC, the RBNZ still responded in a destabilizing way to US-sourced carry trades. Our work also reveals that carry trades destabilize even more New-Zealand’s economy when the US are engaged in a quantitative easing policy.