ENT/LIS/GEO 530

The Constitution says…Article 1, Section 2 of the United States

Constitution: “Representatives and direct taxes shall be

apportioned among the several states which may be included within this union, according to their respective numbers ... The actual Enumeration shall be made within three years after the first meeting of the Congress of the United States, and within every subsequent term of ten years, in such manner as they shall by law direct.”

Basics of Census 2000Short Form

Survey of 100% of the population

Questions about the basic demographic characteristics

age, race, number of people in a housing unit

Long FormSample of one in six

housing unitsBasic demographic

questions PLUS questions

about socioeconomic topics education, income,

housing characteristics, employment, and disability status

Basics of Census 2010Short Form

Continue constitutionally mandated short form counting 100% of the population

Long FormReplaced by the

American Community Survey (ACS)

Census count is focused on coverage

American Community Survey is focused on content

Basics of the American Community Survey

A nationwide, continuous monthly surveyAnnual sample size = around 3 million

addressesData products will be released annually

Profiles available every year for communities of 65,000 or more people

Profiles available in 3 to 5 year estimates for communities with fewer than 65,000 people

Benefits of the ACSProvides timely data between the decennial

censusesExamples in past decade when would matter?

Provides ability to monitor trends in local communities between censusesExamples of how useful?

Permanent, professional interviewersWhy matter?

But keep in mind …Estimates

Sample is small and requires aggregation of data over time for smaller locations

Point in time versus period dataCounting on April 1 of census year versus

counting continuously throughout yearMargins of error and confidence

intervalsFigures are an estimate with a confidence

interval of 90%

Availability for particular places

Reidsville, NC has 14,485 (Census 2000)

5-year estimate (2005-2009) available now

Burlington, NC has 49,038 (ACS 2006-2008)

Two 3-year estimates (05-07 & 06-08) and one 5-year estimate.

Greensboro, NC has 242,817 (ACS 2006-2008)

Any 1-year, 3-year, 5-year estimate could be used.

Point in time versus period data

Census American Community Survey

Point in time dataReference point is April 1

Period dataReference period is past

12 months

Differences in QuestionsCensus American Community

Survey31. INCOME IN 1999a. Wages, salary,

commissions, bonuses, or tips from all jobs - Report amount before deductions for taxes, bonds, dues, or other items.O Yes

Annual amount – Dollars $[ ][ ][ ],[ ][ ][ ].00O No

47. INCOME IN THE PAST 12 MONTHS.

a) Wages, salary, commissions, bonuses, or tips from all jobs.

Report amount before deductions for taxes, bonds, dues, or other items Yes -->

$____________________.00 (TOTAL AMOUNT for past 12 MONTHS)

No

Margins of ErrorCensus data has margins of error built in;

ACS data publishes the MoECensus Bureau data has a confidence interval

of 90%How would we interpret this?

Albany County 258, 649 +/-2,191We are 90% confident that the true value is

between 256,458 and 260,840. There is a 10% probability that the estimate would be outside this range.

Putting it into practice

Question Questions to ask

• I’m looking for recent information on number of people by age and race for census tracts in Greensboro, NC.

Time?What is recent? 2000 or

2005-2009 data?Geography?

Census tractsTopic of question?

Age and race of people

American FactFinder (AFF)Contains

American Community SurveyCensus 2010 & 2000 dataEconomic CensusPopulation estimatesAnd more!

http://factfinder2.census.gov/

References Herman, E. (2008). The American Community Survey: An introduction to the

basics. Government Information Quarterly 25, 504-519.

Mather, M., Rivers, K. L., & Jacobsen, L.A. (2005). The American Community Survey. Population Bulletin, 60(3), 3-20.

North Carolina Office of State Budget & Management. (2008). NC SDC 2008 Annual Meeting Materials. Retrieved January 27, 2009 from http://www.osbm.state.nc.us/ncosbm/facts_and_figures/state_data_center/AnnualMeetings/ 

North Carolina Office of State Budget & Management. (2008). North Carolina is counting on you! Retrieved January 27, 2009 from http://www.osbm.state.nc.us/ncosbm/facts_and_figures/census/nc2010/

Taeuber, C. M. (2006). American Community Survey for Community Planning. Oxford: Trafford Publishing.

U.S. Bureau of the Census. (2008). A compass for understanding and using American Community Survey Data What general data users need to know. Retrieved December 1, 2009 from

http://www.census.gov/acs/www/Downloads/ACSGeneralHandbook.pdf