"This book on advanced econometrics is intended to familiarise the reader with technical developments in the area of econometric which is known under the label treatment e ect estimation, or impact or policy evaluation. In this book we have tried to combine the intuitive reasoning for identi cation and estimation with the econometric and statistical rigorousness. This holds especially for the complete list of stochastic assumptions and their implications in practise. Moreover, for both, identi cation and estimation we focus mostly on nonparametric methods (i.e. our methods are not based on speci c pre-speci ed models or functional forms) in order to provide methods that are quite generally valid. Graphs and a number examples of evaluation studies are applied to explain how sources of exogenous variation can be explored for disentangling causality from correlation"--