This course provides an introduction to business cycles with applications in monetary policy, providing a natural progression from ECON 5140. It includes Real Business Cycle (RBC) models, monetary models, Dynamic Stochastic General Equilibrium Models (DSGE) and models with New Keynesian frictions, including nominal rigidities and financial frictions. In this course, students will learn how to solve various models analytically using dynamic programming and sequential methods. Key topics in monetary policy (or monetary economics) such as money neutrality, super money neutrality, the Fisher equation, Friedman rule, equilibrium determinacy, time inconsistency and reputation in monetary policy are also explored in this course. Numerical solution techniques are emphasized with calibration and simulation methods taught using Matlab, Octave and Dynare, to compute the quantitative impact of economic shocks and policy events. Bonus computing workshops will be provided. Applications to policy and real-world phenomena are emphasized throughout.