Markus Kr�tzig is a doctoral student in the Department of Economics at Humboldt University, Berlin.
Michael Wickens is professor of economics at the University Michael Wickens is professor of economics at the University of York. He is the coeditor of "Handbook of Applied Econometof York. He is the coeditor of "Handbook of Applied Econometrics" and was managing editor of the" Economic Journal" fromrics" and was managing editor of the" Economic Journal" from 1996 to 2004. 1996 to 2004.