Metric 1 — STEM Occupations per 1,000 employed
For each county, we sum the count of employed civilians 16 years and over
in occupations that fall under the Census Bureau's STEM occupation definition,
then divide by total employed civilians and multiply by 1,000.
Source:
ACS 5-year, Table C24010
(“Sex by Occupation for the Civilian Employed Population 16 Years and Over”).
Counts are summed across both sexes for each STEM-relevant occupation group.
The default uses the narrow Census definition; switching the dropdown above to
“Inclusive” adds healthcare practitioner and technical occupations to
the numerator.
Note: BLS Occupational Employment & Wage Statistics (OEWS) is not used,
because OEWS is not published at the county level for many non-metro counties.
ACS C24010 is the only county-resolved occupation table available nationwide.
Metric 2 — % of Bachelor's-or-Higher holders with a STEM degree
For each county, we sum first-major bachelor's degrees in Science & Engineering fields
and divide by the total population age 25+ holding a bachelor's degree or higher.
Source:
ACS 5-year, Table B15012
(“Sex by Field of Bachelor's Degree for First Major”) for the numerator,
and Table B15003
(“Educational Attainment for the Population 25 Years and Over”)
summed across bachelor's, master's, professional, and doctorate categories
for the denominator.
Note on the denominator: “% of County Population with Bachelor's
Degree or Higher” can read ambiguously. Here, the denominator is bachelor's-or-higher
holders (B15003 categories 22–25 summed), not the full population 25+, so the
metric measures the STEM concentration within the educated workforce rather than
against everyone 25+.
Quartile Ranking
Each county is assigned to Lower 25%, Mid-Tier, or
Upper 25% based on its position in the distribution of the metric across
all counties in the same state. Cutoffs are the 25th and 75th percentiles, computed live
each time the underlying data refreshes.