Three essays compose the dissertation. In the first essay, entitled Interest Rate Rules, Endogenous Fluctuations and Chaotic Dynamics in Open Economies (joint with Luis-Felipe Zanna), we study the consequences for global equilibrium determinacy of implementing active interest rate rules (i.e. whereby the nominal interest rate responds more than proportionally to changes in inflation) in flexible-price open economies. We show that conditions under which these rules generate aggregate instability by inducing cyclical and chaotic equilibrium dynamics depend on particular characteristics of open economies such as the degree of (trade) openness and the degree of exchange rate pass-through. We find that a forward-looking rule is more prone to i...