Research · ACS 2020-2024
How reliable are census figures for small towns?
For 22% of U.S. places with fewer than 1,000 residents the Census Bureau publishes no median household income at all, and for another 11% the estimate's coefficient of variation is over 40%, too uncertain to rely on.
How does reliability change with a place's size?
The American Community Survey reaches about one household in eight over five years. In a town of 500 that is a few dozen households, so a median income can swing by tens of thousands of dollars from sample to sample.
| Size (2020 Census) | None published | Unreliable | Fair | Reliable |
|---|---|---|---|---|
| 100,000+340 places | 0.0% | 0.0% | 0.0% | 100.0% |
| 10,000-99,9993,812 places | 0.0% | 0.0% | 3.7% | 96.3% |
| 1,000-9,99911,392 places | 1.1% | 2.2% | 50.1% | 46.5% |
| under 1,00016,786 places | 22.2% | 10.9% | 49.5% | 17.4% |
Census tracts, drawn to hold about 4,000 people, sit in between: of 85,382 tracts, 1,554 have no published median income and 1,250 an unreliable one.
An example: Allgood, AL (759 residents) has a published median household income of $73,750, with a 90% margin of error of ±$42,510.
Source: ACS 2020-2024 5-year estimates, published margins of error (DP03) · ACS technical documentation
What should a reader do with a small town's figures?
Read the margin before the number. Use the 2020 Census count for population (a full count, not a sample). Compare two small places only when their margins do not overlap. Prefer the county's figures when the question is about the area rather than the town. PlainCities marks every estimate with a coefficient of variation over 40% with a ring and leaves it out of rankings.
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections