Measuring diversity can be tricky. We could, for example, calculate the percent of whites (or blacks) in a campus population and conclude that the higher the percent, the less diverse is the campus population.

Economists use a Hirschman-Herfindahl Index (HHI) to look at concentration in an industry. The Justice Department and the Federal Trade Commission use the HHI in antitrust cases. The measure is pretty simple – calculate the sum of the squared percentage market shares. If an industry is monopolized by one firm, the HHI is 10,000. If there are 100 firms, each with a 1% market share, the HHI is 100. So the HHI is bounded below by zero and above by 10,000, creating a simple index number of concentration.

IPEDS allows us to put our students into 18 race / ethnicity boxes, 9 for each gender. If all 18 categories had exactly 5.5% of a diversity “share”, the diversity HHI for a college would be 555. If a 2000 student campus had 500 black men, 500 black women, 500 white men and 500 white women , the HHI would be 2500.

The attached spreadsheet using 2010 data calculates HHIs for about 100 institutions in an IPEDS category of “like” institutions. (I have further sorted down based on my own bias as to the definition of a “like” institution.

Alma and Hope are least diverse, and Earlham and Swarthmore are most diverse by this measure. Wittenberg is in the 35th position of 53 on the list – toward the less diverse end. While we are reasonably well represented in the number of black students on campus, our Asian and Hispanic numbers are low compared to some on the list.