Fiscal and monetary policy in new Keynesian DSGE models

This thesis is about monetary and fiscal policy in New Keynesian DSGE models. Chapter 2 presents the baseline New Keynesian DSGE model. Monetary policy is in the form of a simple interest rate Taylor-type policy rule, while fiscal policy is exogenous. Chapter 3 extends the model of Chapter 2 to include fiscal policy. Now, both monetary and fiscal policy are allowed to follow feedback rules. Chapter 4 sets up a New Keynesian model of a semi-small open economy with sovereign risk premia. Finally, Chapter 5 builds a New Keynesian DSGE model consisting of two heterogeneous countries participating in a monetary union.Throughout most of the thesis, policy is conducted via "simple", "implementable" and "optimized" feedback policy rules. Using such rules, the aim of policy is twofold: firslty, it aims to stabilize the economy when the latter is hit by shocks; secondly, it aims to improve the economy's resource allocation.