SANDRINE LARDIC is Senior Lecturer in Economics at the University of Paris X (France) and also is consultant for Sinopia Asset Management. She carries on research concerning econometrics in the fields of financial markets and macroeconomics. She is the author of books and papers on theoretical and applied econometrics. - VALERIE MIGNON is Professor of Economics at the University of Paris X (France). She conducts research on theoretical econometric methods and applied econometrics in the fields of financial markets and macroeconomics. Her research interests include long-memory processes and non-linear econometrics. She is the author of books and papers on theoretical and applied econometrics.