Question 1

Where does this demographic data come from?

Accepted Answer

All demographic data comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates, which samples about 3.5 million households annually. The 5-year estimates provide the most reliable data for small geographies like municipalities.

Question 2

What is the difference between Census data and ACS data?

Accepted Answer

The decennial Census (conducted every 10 years) is a full population count focusing on basic demographics. The ACS is an ongoing survey that collects detailed data on income, education, housing, commute patterns, and more. ACS data is updated annually but represents averages over a 5-year period.

Question 3

How accurate is this data for small towns?

Accepted Answer

For smaller municipalities, ACS estimates have wider margins of error because fewer residents are sampled. The 5-year estimates reduce this uncertainty by averaging over a longer period. For towns under 5,000 people, treat specific numbers as approximations rather than precise counts.

Johnston, IA