This dissertation investigates the role of financial markets as a driving force behind business cycle fluctuations and studies effective monetary policy responses that mitigate the negative economic impact of such fluctuations. The first chapter empirically investigates the consequences of the 2007 interbank market freeze and provides a new theoretical framework to study the economic benefits and risks arising from complex financial networks. I use highly detailed proprietary microdata from the German Bundesbank to provide evidence that exposure to the US financial market had a negative impact across several measures on domestic German monetary financial institutions (MFIs) and their clients. I develop a dynamic stochastic general equilibri...