This will help you interpret the Harvard ranking!
From our beloved John Campbell,
Dear students, staff, and faculty of the economics department:
The National Research Council has today released its long-awaited Assessment of Research Doctoral Programs. The assessment combines measurable characteristics of departments and PhD programs with faculty ratings, which are used to determine the relative weights on the measurable characteristics. The assessment reports two alternative rankings, each in the form of a 90% confidence interval that represents uncertainty about the relative importance of different characteristics.
The confidence interval for our PhD program covers the range from #1 to #1 in both rankings. Rival PhD programs have wider confidence intervals starting at #2. In other words, the assessment finds that instead of a group of “top five” PhD programs, there is a top PhD program and a group of “almost top” PhD programs.
Assessment of Research-Doctorate Programs