Dueling Data: Diverse Cities

CHALLENGE:
I read an article recently that ranked the most diverse cities in America. Because the article failed to elaborate on the methodology they used to calculate diversity I decided to create my own metric.

APPROACH:
So I pulled 2011 population and race estimates from the census for all Metropolitan Statistical Areas (MSAs). MSA is defined as the city and surrounding neighborhood. For the purpose of this analysis I used seven racial groups provided by the Census:

Hispanic
White
Black
Asian
American Indian
Pacific Islander
Multi-Racial

The new metric called Diversity is based on the aggregated absolute difference between the relative sizes of all racial groups in the city. For example, if all racial groups are equally represented in the city (e.g. each group comprises 14.3% of the population) than the diversity score would be 0%. A city where there is only race (e.g. city is 100% Hispanic) the diversity score would be 171%.

FINDINGS:
The follow is the result of this analysis. Vallejo is the most diverse city in the U.S. with large percentages of Whites, Asians, and Hispanics. The least diverse cities in the U.S. have large White or Hispanic populations. Cities in California and Texas are significantly more diverse than the Midwest due in large part to significant Hispanic populations. The least diverse large city (3+ million people) is Minneapolis, MN which is 79% White. The most diverse are San Francisco, New York, and Washington, DC.