Wolfgang Karl Härdle is a Ladislaus von Bortkiewicz Professor of Statistics at the Humboldt-Universität zu Berlin and director of C.A.S.E. (Center for Applied Statistics and Economics), director of the CRC-649 (Collaborative Research Center) “Economic Risk” and director of the IRTG 1792 “High Dimensional Non-stationary Time Series”. He teaches quantitative finance and semi-parametric statistics. His research focuses on dynamic factor models, multivariate statistics in finance and computational statistics. He is an elected member of the ISI (International Statistical Institute) and advisor to the Guanghua School of Management, Peking University. Léopold Simar is an Emeritus Professor of Statistics at Université de Louvain, Louvain-la-Neuve, Belgium. He has been teaching mathematical statistics, multivariate analysis, bootstrap methods in statistics and econometrics in several Universities in Europe. His research focuses on non-parametric and semi-parametric methods and bootstrap techniques in statistics and econometrics. He is an elected member of the ISI and the past President of the Belgian Statistical Society. He is a regular Visiting Professor at the University of Roma, La Sapienza, Roma, Italy and at the Toulouse School of Economics, Toulouse, France.