Glossary of Census & Demographic Terms

Short, plain-English definitions of the terms used throughout StateDemographics.com. For how we compute each figure, see the methodology page.

American Community Survey (ACS): The Census Bureau’s ongoing survey of about 3.5 million households per year, covering income, housing, education, and employment. It is the source of every figure on this site. The "5-Year Estimates" pool five years of responses so that even very small communities can be measured reliably.
Census-Designated Place (CDP): An unincorporated community that the Census Bureau defines for statistical purposes — a recognizable named place with no municipal government of its own. CDPs appear alongside incorporated cities and towns in our city lists.
County equivalent: A geography that functions as a county in Census data without being called one: Louisiana parishes, Alaska boroughs and census areas, Puerto Rico municipios, independent cities (such as Baltimore or Richmond), and Connecticut’s planning regions.
Median household income: The income of the household exactly in the middle of a community’s income distribution — half of households earn more, half earn less. Unlike the average (mean), it is not pulled upward by a small number of very high earners, which makes it the standard measure of typical living standards.
Median home value: The middle value of owner-occupied homes, as estimated by their owners in the ACS. It covers only homes that are owned and lived in — not rentals, vacation homes, or recent sale prices.
Median age: The age that splits a population in half: as many residents are older than this age as are younger.
Poverty rate: The share of residents living below the federal poverty threshold, which varies by household size but is the same everywhere in the country. Because it ignores local living costs, it can understate hardship in expensive areas and overstate it in inexpensive ones.
Unemployment rate: Unemployed people as a share of the civilian labor force (those working or actively looking for work). ACS unemployment is a five-year survey average, so it differs from the official monthly rate published by the Bureau of Labor Statistics.
Labor force participation: The share of people 16 and older who are either working or actively looking for work. Students, retirees, and those not seeking work are outside the labor force.
Homeownership rate: Owner-occupied housing units as a share of all occupied units. It counts households, not people — a city of young renters and a city of longtime owners can have similar incomes but very different rates.
Bachelor's degree or higher: The share of adults 25 and older whose highest completed education is a bachelor’s, master’s, professional, or doctoral degree. The standard Census measure of educational attainment.
Home-value-to-income ratio (affordability ratio): Median home value divided by median household income — how many years of gross income a typical home costs. Around 3x has historically been considered comfortably affordable; the most expensive markets exceed 8x.
Diversity index: A 0–100 score equal to the probability that two randomly chosen residents belong to different racial or ethnic groups. Computed as 1 minus the sum of squared group shares (a Simpson/Herfindahl-style index). A city where one group makes up nearly everyone scores near 0; a city split evenly among several groups scores high.
Hispanic or Latino: In Census data, an ethnicity rather than a race — a person of any race can be Hispanic or Latino. On this site, all other race groups (White, Black, Asian, etc.) count only their non-Hispanic members, so the shares sum to 100%.
Margin of error: The uncertainty band around a survey estimate. Every ACS figure has one, and smaller communities have wider bands. The Census Bureau publishes the margin for every estimate at data.census.gov; treat small-town figures as approximations.
Top-coding: The ACS caps published medians at $250,001 for household income and $2,000,001 for home value. A community at the cap has a true median at least that high. We display these as $250,000+ and $2,000,000+.