In recent years non-linearities have gained increasing importance in economic and econometric research, particularly after the financial crisis and the economic downturn after 2007. This book contains theoretical, computational and empirical papers that incorporate non-linearities in econometric models and apply them to real economic problems. It intends to serve as an inspiration for researchers to take potential non-linearities in account. Researchers should be aware of applying linear model-types spuriously to problems which include nonlinear features. It is indispensable to use the correct model type in order to avoid biased recommendations for economic policy.