Refer to the Southern Economic Journal (Apr. 2008) study of Ph.D. programs in economics, Exercise. The authors also made the following observation: “A noticeable feature of this skewness is that distinction between schools diminishes as the rank declines. For example, the top-ranked school, Harvard, has a z -score of 5.08, and the fifth-ranked school, Yale, has a z -score of 2.18, a substantial difference. However, . .. the 70th-ranked school, the University of Massachusetts, has a z -score of −0.43, and the 80th-ranked school, the University of Delaware, has a z-score of – 0.50, a very small difference. [Consequently] the ordinal rankings presented in much of the literature that ranks economics departments miss the fact that below a relatively small group of top programs, the differences in [overall] productivity become fairly small.” Do you agree?