This course follows the first year macro sequence: 501 and 572. Our goal in this course is to learn tools that help us to relate models to data, that is, we aim at learning how to answer quantitative questions and we will learn to do so by doing. This will require intensive computational work by students. We will learn how to construct and characterize equilibrium allocations of representative agent models, overlapping generations models and heterogeneous agents economies. We will learn the computational tools to solve those artificial economies in stationary and non-stationary environments such as business cycles or development processes taking good care of distributions and aggregate consistency. Much emphasis of this course is on the calibration process: we will spend much time discussing the mapping from theory to data. The grade will be some weighted average of regular homeworks, class presentations and a referee report.