What is a census and what kind of data is collected?

Census data can help planners and others understand the social, economic, and demographic conditions in their communities.

Census data is the primary data used by planners to understand the social, economic, and demographic conditions locally and nationally. We sometimes think the census is unique to the United States but census data is collected in other countries, too. The Measure Evaluation document states the United Nation defines a population census as:

The total process of collecting, compiling, and publishing demographic, economic, and social data pertaining to a specific time to all person in a country or fixed or defined area part of a country. Most countries also include a housing census.

The United Nations lists four essential features of a census:

  1. Each individual is enumerated separately; the characteristics of each person within the household are recorded separately.
  2. The census covers a precisely defined territory and includes every person present or residing within its scope. The housing census should include every type of building and living quarters.
  3. Each person and each type of building and living quarters is enumerated with respect to a well-defined point of time.
  4. The census is taken at regular defined intervals, usually every 10 years.


In most countries, people are counted in their place of usual residence.

The Measure Evaluation document outlines the types of data collected in the census:

  • Basic population characteristics including age, sex, marital status, household composition, family characteristics, and household size.
  • Economic measures including labor force participation, occupation, place of work, employment-related industry, and educational attributes such as school attendance, educational attainment, and literacy.
  • Geographic and migration information is also collected. 
  • Questions on place of birth, place of usual residence, duration of residence, and prior place of residence allow planners to examine population movements.
  • Some countries also collect information on births and deaths, especially those that do not have a system that adequately registers these vital events.
  • Information on buildings, living quarters and related facilities.

In the United States and globally, these millions of data points are collected and used to make policy decisions. Most people are familiar with the decennial census, conducted every 10 years, where thousands of people are hired to go around the country and count people.

However, there is also an ongoing statistical survey conducted by the U.S. census bureau. In America, we call this survey the American Community Survey, and this survey continues all year, every year based on randomly sampled addresses in every state, the District of Columbia, and Puerto Rico. Information is collected by mail with some follow-up by phone or personal visit.

Those in Michigan State University Extension that focus on land use provide various training programs on planning and zoning, which are available to be presented in your county.  Contact your local land use educator for more information.

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