CDS Community Development Strategies
Another way to examine diversity at the neighborhood level is to calculate a “diversity index”. In dealing with race and ethnic demographics, a diversity index is a calculation that determines how likely any two randomly-chosen individuals in a given geography will be of a different race or ethnicity. The higher the number, the higher the likelihood. As of the 2010 Census, the 8-county Houston region as a whole had a diversity index of 0.686, or a 68.6% chance that any two randomly-chosen individuals in the region would be of a different ethnic origin.
The following map illustrates the diversity index of Census Block Groups in the Houston region in 2000 and 2010. Diversity index numbers increased in nearly 2/3 of all Block Groups in the region from 2000 to 2010. In 1/2 of all Block Groups there is now diversity index greater than 0.50--a greater than 50% chance that two randomly-chosen individuals will be of a different race or ethnicity.
The map below displays which Block Groups had a higher diversity index than the region as a whole in 2000 and in 2010. Despite a majority of Block Groups experiencing an increase in their diversity index from 2000 to 2010, the number of geographies that contained a higher diversity index than the regional mean dropped during this time. While 12.9% of Block Groups had a higher diversity index than the region as a whole (0.656) in 2000, only 8.4% had a higher figure than the region (a larger 0.686) in 2010.
For more on diversity in the Houston area: a recently-issued study by the Kinder Institute at Rice University examined demographic shifts at the Census Tract-level, specifically looking at the shifts in the largest and second-largest race or ethnicity in a given tract over a 30-year period.
About the Author: Ty Jacobsen is a GIS and Market Analyst with CDS Community Development Strategies. He has worked on numerous demographic studies during his 8 years with CDS, spending at least a quarter of that time attempting to navigate the US Census website.