With Census 2000 data showing a dramatic increase in the nation's racial/ethnic diversity, much of it due to the rise in the Hispanic population nationwide, demographers at Claritas Inc. took a closer look at exactly how counties of 100,000-plus population ranked on diversity in the 1990 and 2000 censuses.
The study found, among other things, that California dominated the Census 2000 diversity score rankings with nine counties in the Top 20, two of which were in the Top 10.
Those two counties were Alameda County and Los Angeles County, coming in at two and nine respectively. Since 1990, Alameda jumped six places from number eight, and Los Angeles fell five spots from fourth. The other California counties in the Census 2000 Top 20 (and where they ranked in 1990) are:
-- No. 11 -- San Francisco (3rd)
-- No. 12 -- Solano (22nd)
-- No. 13 -- Santa Clara (19th)
-- No. 16 -- San Joaquin ( 21st)
-- No. 18 -- San Mateo (24th)
-- No. 19 -- San Bernardino (34th)
-- No. 20 -- Fresno (14th)
Shifting to the east coast, New York state was second with four counties, including the number one county, Queens, and three others in the top 10. Queens was also number one in 1990 and its diversity score increased by just over six points from 67.5 in 1990 to 73.6 over the 10-year span.
The diversity score reflects the probability that two persons selected randomly from a county's population would be of different race/ethnicity. The higher the score, the greater the race/ethnic diversity, explained Ken Hodges, director of demography at Claritas.
"Select a person from Queens and almost three out of four times, the second person selected will be of a different race/ethnic category," said Hodges.
Hodges said the diversity score was computed for 3,139 counties nationwide, adding that over 91 percent (2,873 counties) experienced an increase in diversity over the decade. The diversity score for the total U.S. population increased from 40.4 in 1990 to 47.7 in 2000.
Like Queens, Manhattan maintained its 1990 ranking at seventh with a modest increase in its diversity score from 65.6 to 67.1. Kings County (Brooklyn) slipped from number two in 1990 to number three in 2000, also with a marginal diversity score increase -- 67.5 to 69.7. Bronx County had a significant drop from the fifth spot in 1990 to 17 in 2000, but with only a slight drop in diversity score from 66.3 to 63.6.
Texas came in third with three counties, Fort Bend (5th, Houston area), Harris (8th, Houston) and Dallas (10th). Dallas County also made the largest leap in ranking, moving 18 spots from 28th place in 1990.
Hodges noted that comparisons of 1990 and 2000 census race (and diversity) are complicated by differences between 1990 and 2000 census race definitions. "The 2000 census was the first to permit respondents to mark more than one race, thus expanding a simple set of five race categories to a list of 63 -- including the combinations of two or more races. Claritas bridged or estimated the 2000 census race data back to 1990 definitions to enable comparisons between the two censuses," he said.
The race/ethnic categories examined were:
-- White, non-Hispanic
-- Black, non-Hispanic
-- American Indian, Eskimo or Aleut, non-Hispanic
-- Asian or Pacific Islander, non-Hispanic
Claritas also ranked the Top 20 large counties by increase and decrease in diversity score. Of large counties that increased, two in the Atlanta area came in first and second, Gwinnett and Cobb, and, overall, Georgia had the most with four, all in the top 10. The other two are Hall County at number four and Clayton County at number 10. Gwinnett County had an increase of 30.9 points from 1990 to 2000, going from 19.6 to 50.5. Cobb County nearly doubled over the 10-year span from 24.7 to 47.2, a jump of 22.5 points.
Elsewhere, Florida placed three in the top 20, Osceola, (3rd), Broward (7th) and Orange (14th). Arkansas, New Jersey, Oregon and Virginia all had two each.
In the list of Top 20 counties that decreased in diversity score, Texas was far and away the leader with six counties, including the number one and three counties, El Paso and Hidalgo. Three states, California, Florida and Maryland, had two each. (NOTE: When active, both listings will be accessible via designated links at Census.Claritas.com).
Hodges explained that, while decreasing diversity runs counter to the trend, it does not mean that an area is increasingly White, or has declining Black, Asian, American Indian or Hispanic populations.
For example, the diversity score in El Paso County dropped because its Hispanic population increased from 69.6 percent to 78.2 percent, while White, non-Hispanic, dropped from 25.7 percent in 1990 to 17.4 percent in 2000.
Similarly, in Prince George's County, MD, which experienced a drop in diversity score, Black, non-Hispanic, population increased from 50.2 percent to 63.1 percent, while White, non-Hispanic, dropped markedly from 41.6 percent to 25 percent.
"In short, large counties where the diversity score decreased tended to be those with a large Hispanic, Asian or Black population in 1990 that became even more predominant by 2000," said Hodges.