Ranking Ph.D. programs in economics (cont’d) . Refer to the Southern Economic Journal (Apr. 2008) study of Ph.D. programs in economics, Exercise 2.121. 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?

Exercise 2.121

Ranking Ph.D. programs in economics. Thousands of students apply for admission to graduate schools in economics each year with the intention of obtaining a Ph.D. The Southern Economic Journal (Apr. 2008) published a guide to graduate study in economics by ranking the Ph.D. programs at 129 colleges and universities. Each program was evaluated according to the number of publications published by faculty teaching in the Ph.D. program and by the quality of the publications. Data obtained from the Social Science Citation Index (SSCI) were used to calculate an overall productivity score for each Ph.D. program. The mean and standard deviation of these 129 productivity scores were then used to compute a z-score for each economics program. Harvard University had the highest z -score (z = 5.08) and, hence, was the top-ranked school; Howard University was ranked last since it had the lowest z -score (z =0.81). The data (z -scores) for all 129 economic programs are saved in the ECOPHD file.

a. Interpret the z -score for Harvard University.

b. Interpret the z-score for Howard University.

c. The authors of the Southern Economic Journal article note that “only 44 of the 129 schools have positive z -scores, indicating that the distribution of overall productivity is skewed to the right.” Do you agree? (Check your answer by constructing a histogram for the z -scores in the ECOPHD file.)