[1] Univ Wisconsin Madison, Wisconsin Sch Business, Madison, WI 53706 USA
[2] Univ Wisconsin Madison, Sch Med & Publ Hlth, Madison, WI 53726 USA
[3] Koc Univ, Dept Ind Engn, TR-34450 Sariyer, Turkey
[4] Univ Penn, Wharton Sch, Philadelphia, PA 19104 USA