[1] Belfius Bank & Insurances, Strateg Res, Karel Rogierpl,11,RT17, B-1210 Brussels, Belgium
[2] Hasselt Univ, Fac Business Econ, Martelarenlaan 42, B-3500 Hasselt, Belgium
[3] Stat Netherlands, CBS Weg 11, NL-6412 EX Heerlen, Netherlands
[4] Hasselt Univ, Fac Sci CENSTAT, Agoralaan,Bldg D 42, B-3590 Diepenbeek, Belgium