1. Barbara Kowalczyk is an Associate Professor with the Collegium of Economic Analysis, SGH Warsaw School of Economics, Al. Niepodległości 162, 02-554 Warsaw, Poland. Wojciech Niemiro is Professor with the Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Banacha 2, 02-097, Warsaw, Poland and Professor with the Faculty of Mathematics and Computer Science, Nicolaus Copernicus U