“…Hierarchical regression was selected in this case so that we could control for both ethnicity (Brewster and Mallinson, 2009;Kerr and Domazlicky, 2009;Lynn, 2004aLynn, ,b, 2006Lynn and Thomas-Haysbert, 2003) and whether the participant had ever worked in the service industry (Rogelberg et al, 1999;Conlin et al, 2003;Harris, 1995). A fourth dependent variable, the range of tip size between exceptional and poor service, was also created from the existing data.…”