The American Community Survey An Update

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The American Community SurveyAn Update

• Pamela Klein
• American Community Survey Office
• Washington Metropolitan Council on Governments
• Cooperative Forecasting and Data Committee
• Washington, DC
• January 9, 2007

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Purpose of the ACS

• Collect detailed Census sample data every month
  instead of only once each decade
• Release tabulations of these data on a yearly
  basis
• Restructure and simplify the 2010 Census

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Release schedule for the ACS Data Products
Data products are released in the year following
the single-year or multi-year period in which
data are collected.
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2005 Geographic Areas
Type of Legal, Administrative, or Statistical Area Number included in 2005 ACS for the United States Number included in 2005 ACS for Puerto Rico Percent of All Such Areas
Nation 1 -- 100
States (including DC and Puerto Rico) 51 1 100
Census Regions and Census Divisions 13 -- 100
Congressional Districts 436 1 100
Urban/Rural State Components (excluding DC) 50 1 100
Public Use Micro Data Sample Areas 2,071 30 100
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2005 Geographic Areas
Type of Legal, Administrative, or Statistical Area Number included in 2005 ACS for the United States Percent of All Such Areas Number included in 2005 ACS for Puerto Rico Percent of All Such Areas
Metropolitan, Micropolitan and Combined Statistical Areas 612 58 11 69
Counties and Municipios 776 25 12 15
School Districts 995 7 1 100
Places 469 2 7 3
American Indian and Alaska Native Areas 15 2 -- --
Minor Civil Divisions 188 2 -- --
Other Geographic Areas 3,934 3 24 53
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• Sampling Error
• Sampling error occurs when estimates are derived
  from a sample rather than a census of the
  population.
• Standard error is an estimate of the precision of
  the estimates.
• The margin of error describes the precision of
  the estimate for a given confidence level and
  standard error.
• Tools used to prevent incorrect conclusions

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Margin of Error
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Statistical Significance

• Small differences may be insignificant.
• To do statistical testing of two estimates, you
  must calculate the standard error of the
  difference of the estimates.
• Two estimates are "significantly different" if
  their difference is large enough that there was a
  less than 10 percent chance that the difference
  was purely random.

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Using ACS Data

• ACS data are comparable to Census 2000
• Comparing 2005 ACS data with 2004 ACS data
• Percentage distributions

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Reference Materials
http//www.census.gov/acs/www/

• ACS Data User Training Guide
• ACS Design and Methodology technical document
• Using Data From the 2005 ACS

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Data Products

• Detailed Tables
• Data Profiles
• Narrative Profiles
• Ranking Tables
• Thematic Maps
• Geographic Comparison Tables
• Subject Tables
• Selected Population Profiles

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Public Use Microdata Sample (PUMS)
http//factfinder.census.gov/home/en/acs_pums_2005
.html
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2005 Users Guide
http//www.census.gov/acs/www/Products/users_guide
/index.htm
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Thematic Maps
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Data Profiles
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Geographic Comparison Tables
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Selected Population Profiles
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Using the options tab, you can display
information by different geographic components,
such as urban and rural.
Detailed Tables
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For More Information
American Community Survey Office 1-888-346-9682 cm
o.acs_at_census.gov www.census.gov/acs/www
ACS Alert http//www.census.gov/acs/www/Special/Al
erts.htm
U.S. DEPARTMENT OF COMMERCE U.S. Census
Bureau Washington, DC 20233