1. Department of Engineering, Reykjavik University, Reykjavik, Iceland
2. Department of Operations Research, AGH University of Science & Technology, Kraków, Poland
3. Department of Business Informatics and Engineering Management, AGH University of Science & Technology, Kraków, Poland
4. Department of Statistics, Computer Science and Mathematics, Public University of Navarre, Pamplona, Spain
5. Haas School of Business, University of California, Berkeley, Berkeley, CA, USA