John Bucksbaum

[5] Bucksbaum worked only for his father's company and started out sweeping the mall floors and cutting the grass as a kid.

[3] In 1999, Bucksbaum succeeded his father as the chairman and chief executive officer of GGP.

With Steiner + Associates, he developed Liberty Center, a mall in Cincinnati, Ohio.

[3] They founded the Jacolyn and John Bucksbaum Foundation, which focuses on early childhood development, Jewish education, sports, and arts and civic organizations in Aspen and Chicago.

[6] Bucksbaum is on the board of the Field Museum and the Chicago International Film Festival.