How PopulationReview Builds Demographic Profiles

PopulationReview compiles demographic profiles for every U.S. state, county, city, and ZIP code from public-domain federal statistical sources — primarily the U.S. Census Bureau American Community Survey 5-year estimates, with vital statistics from the CDC and cost-of-living adjustments from the Bureau of Economic Analysis. We do not use proprietary, paywalled, or estimated data.

Primary Data Sources

The single largest input is the U.S. Census Bureau American Community Survey (ACS) 5-year estimates, which the Census Bureau publishes each December for every U.S. geography down to the block-group level. We pull more than 200 ACS tables covering population (B01001), age structure (B01002), race and ethnicity (B02001, B03003), income (B19013, B19001), poverty (B17001), educational attainment (B15003), housing tenure and value (B25077, B25064), language spoken at home (B16001), commute mode (B08301), and disability status (B18101). Birth rates and other vital statistics come from the CDC National Center for Health Statistics. Cost-of-living indices use the Bureau of Economic Analysis Regional Price Parities series. Rural and farm-economy data uses the USDA Economic Research Service county typology codes. Land use, housing supply, and migration analyses cross-reference research from the Lincoln Institute of Land Policy.

Why ACS 5-Year (Not 1-Year)

The Census Bureau publishes ACS estimates in three vintages: 1-year (only for geographies with at least 65,000 people), 3-year (discontinued), and 5-year (every geography down to the block group). Because PopulationReview profiles every U.S. ZIP code and every county — including the roughly three-quarters of U.S. counties below the 65,000-person threshold — the 5-year file is the only product that gives full geographic coverage. Trade-off: 5-year estimates are a trailing average, so a recent shock (a hurricane, a refinery closure, a population boom) can take two to three publication cycles to fully show up. We document the ACS vintage in every entity page footer so readers can see exactly which 5-year window the figure represents.

How We Compute Rankings and Derived Metrics

Several of our most popular pages are rankings — fastest-growing states, richest cities, most diverse counties — and the methodology behind each is explicit. Population growth rankings compare the latest ACS 5-year population estimate to the most recent decennial census count (Census Table P1) and convert that to a compound annual rate, which avoids the artifact where a small absolute gain looks dramatic in a tiny town. Income rankings use ACS Table B19013 (median household income, inflation-adjusted to the most recent ACS dollar year) — never mean income, because mean is distorted by a few high earners. Cost-adjusted income combines median income with the BEA Regional Price Parities so that $60,000 in Mississippi and $60,000 in Manhattan are compared on equal purchasing-power footing. Diversity rankings use the Simpson's Diversity Index applied to the five OMB-15 race categories plus Hispanic origin.

Data Pipeline

Each ACS release triggers a four-step pipeline. Step 1: pull every relevant table from the Census Bureau Data API for all 50 states, ~3,143 counties, ~330 metropolitan statistical areas, and ~33,000 ZIP code tabulation areas. Step 2: validate (every row has a complete set of expected variables, every variable resolves to a non-null number where the Census flag indicates available data). Step 3: derive — Simpson's diversity, cost-adjusted income, share of foreign-born, share of households cost-burdened (paying more than 30% of income on housing), and the dozen other indices that show up on entity pages. Step 4: write static JSON files per entity and re-render the site. Total pipeline runtime is under 30 minutes; outputs are diffed against the prior vintage and a release report flags any geography whose value changed by more than two standard deviations of the historical series (a strong signal that something needs human review).

Update Frequency

Census ACS 5-year estimates publish on a fixed annual schedule, typically the first Thursday of December, covering the prior 5-year window (the December 2025 release covers 2020 through 2024). PopulationReview reruns its full pipeline within 30 days of each release. CDC vital statistics update annually each spring. BEA Regional Price Parities update annually each November. The site's last full data refresh was May 2026; every entity page shows the underlying ACS vintage in its data-source footnote, so you can always see exactly which years a figure covers.

Known Limitations

• Trailing window. The 5-year ACS file is a moving average, so a recent population shock (boom, bust, disaster displacement) takes several publication cycles to fully appear.
• Small-geography noise. ZIPs and small towns under about 5,000 people have wide margins of error on every ACS variable. We display the central estimate but the true value can sit several percentage points above or below.
• Race and ethnicity self-report. Categories follow the OMB Directive 15 standard used by Census. They are self-reported and do not always align with how individuals describe themselves or with the categories used by other agencies.
• Income inflation adjustment. All income figures are inflation-adjusted to the most recent ACS dollar year. Cross-vintage comparisons (e.g., 2018 vs 2024) require care because the deflator series itself is revised over time.
• ZIP geography drift. ZIP Code Tabulation Areas (ZCTAs) are Census-Bureau approximations of USPS delivery routes; they shift slightly between vintages and do not always match a current postal ZIP one-to-one.

Citation

If you reference PopulationReview material in your own work, please cite:

PopulationReview. "[Page Title]." populationreview.org, 2026. Accessed [date]. Underlying data: U.S. Census Bureau American Community Survey 5-year estimates.

Underlying Census, CDC, BEA, and USDA data is U.S. government public domain. PopulationReview's editorial framing, derived indices, and structured presentation are licensed for educational reuse with attribution.

Frequently Asked Questions

How We Compare to Other Demographic Aggregators

Population Review is one of several sites that re-publish federal demographic data. Two things distinguish our approach from common alternatives like WorldPopulationReview: we cite the exact ACS table and vintage on every entity page (no synthetic year-token swaps), and we publish the underlying datasets as free CSV files with no email gate. We also do not publish IQ rankings, crime-perception rankings, or composite cost-of-living indices sourced from non-federal datasets, because we cannot defend their methodology to a reader. For a sourced comparison, see:

• Is WorldPopulationReview Accurate?
• Where Does WorldPopulationReview Get Its Data?
• The WorldPopulationReview IQ Data Controversy, Explained
• Free Demographic CSV Downloads