Census 2010 & The American Community Survey

Lynda Kellam The American Community Survey & Census 2010

For what purpose does the Constitution mandate a census every ten years?

Assist local government officials in planning services

Congressional reapportionment and redistricting

Assist federal officials with the distribution of federal funds to state and local governments.

Assist state and local government with evacuation proceedings and disaster planning.

For what purpose does the Constitution mandate a census every ten years?

Assist local government officials in planning services

Congressional reapportionment and redistricting

Assist federal officials with the distribution of federal funds to state and local governments.

Assist state and local government with evacuation proceedings and disaster planning.

The Census Bureau has distributed two forms of questionnaires since which year?

1790

1970

1960

1940

The Census Bureau has distributed two forms of questionnaires since which year?

1790

1970

1960

1940

The Constitutional Requirement

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 .”

The Basics from Census 2000

Short Form

Survey of 100% of the population

Questions about the basic demographic characteristics

age, race, number of people in a housing unit

Long Form

Sample of one in six housing units (approximately 17% sample)

Basic demographic questions

PLUS questions about socioeconomic topics

education, income, housing characteristics, employment, and disability status

The Basics from Census 2010

Short Form

Continue constitutionally mandated short form counting 100% of the population

Long Form (Bye Bye!)

Replaced by the American Community Survey (ACS)

Census count is focused on coverage

ACS is focused on content

American Community Survey

A nationwide, continuous monthly survey throughout decade

Annual sample size is about 3 million addresses

Fully implemented in 2005 and first data product released in 2006

Data 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 ACS

Provides timely data between the decennial censuses

Why would that matter?

Provides ability to monitor trends in local communities between censuses

Why would this matter?

Has permanent, professional interviewers who are more successful at increasing the response rate

Let’s Play with Fact Sheets!!

www.census.gov

But, keep several things in mind!

Estimates

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

Point in time versus period data

Counting on April 1 of census year versus counting continuously throughout year

Margins of error and confidence intervals

Figures are an estimate with a confidence interval of 90%

ACS Releases Dates & Coverage Data Product Population Threshold Year of Data Release 2006 2007 2008 2009 2010 2011 Year(s) of Data Collection 1-year Estimates 65,000 + 2005 2006 2007 2008 2009 2010 3-year Estimates 20,000 + 2005-2007 2006-2008 2007-2009 2008-2010 5-year Estimates All Areas 2005-2009 2006-2010

Availability for particular places Village A has 15,000 Only 5 year estimates available (2005-2009) Town B has 30,000 Three sets of 3 year estimates (05-07, 06-08, 07-09) & one 5 year estimate are available City C has 80,000 (actually 223,891) Five sets of 1 year estimates, three sets of 3 year estimates and one 5 year estimate are available

Just remember…

Best to compare similar estimates:

Do not compare Town B’s 3 year estimate to City C’s 1year estimate

Do compare Town B’s 3 year estimates to City C’s 3 year estimates

Be careful about comparing same area over time:

Do not compare overlapping estimates (e.g., 2005-2007 & 2006-2008)

Do compare 2005-2007 & 2008-2010

Which estimate you choose can change the story!

Point in time versus Period data

Census count is point in time—April 1

ACS is period data

Data collected almost daily and results are aggregated into a specific time period (1 year, 3 years, 5 years)

Not monthly or yearly averages

Data collected from 2005-2007 should not be called “2007” estimates

Reference periods for employment, income, and student enrollment. Be careful comparing census 2000 & ACS data on these topics!

Margins of Error

Data is best estimate but you will need to consider the margin of error

Census Bureau data has a confidence interval of 90%

How would we interpret this?

Albany County 258, 649 +/-2,191

We 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.

Let’s Play with Data Tables!!

www.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