Journey-to-Work Data in the American Community Survey (ACS)
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Transcript of Journey-to-Work Data in the American Community Survey (ACS)
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Journey-to-Work Data in the American Community Survey
(ACS)
May 17, 2009TRB Transportation Planning Applications Conference
Federal Data for Modelers WorkshopHouston, TX
Melissa Chiu, CTPP Coordinator Journey to Work and Migration Statistics Branch
Housing and Household Economic Statistics DivisionU.S. Census Bureau
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What is the American Community Survey?
A large, continuous demographic survey– Produces annually updated single-year and multi-
year estimates of the characteristics of the population and housing
– Produces characteristics, not a population count– Produces information for small areas including
tracts, block groups and population subgroups - updated every year
– Key component of reengineered 2010 census
Survey designed to include– U.S. stateside and Puerto Rico – Population in both housing units and group quarters
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How Does the Sample Compare?
ACS samples every year and spreads sample over 12 months; census samples once a decade and uses the entire sample at the same time
ACS subsamples for personal visit follow-up; court ruled against census subsampling
Census sample estimates based on about 18 million housing units; ACS 5 year estimates based on about 11 million housing units
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ACS Data Release Schedule
Data products are released in the year following the single year or multiyear period in which data are collected.
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December 2008: First Multiyear Estimates
Data collected 2005-2007 – Based on data from housing unit population in 2005-2007;
group quarters population 2006-2007– First release of ACS data for mid-sized counties, other areas– First release of two sets of ACS estimates for states, large
counties, Congressional Districts, Public Use Microdata Areas (PUMAs)
Most data products similar to those of past years
Inflation-adjusted to 2007Geography based on January 2007
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Web Site and Training
ACS Compass Products– Understanding and Using ACS Data:
Handbook Series– Presentations
• Slides and presentation notes• Various aspects of the ACS
– On-line Tutorial – www.census.gov/acs/www/UseData/Compass/compass_series.html
Train the Trainer workshops at SDCs, regional offices, etc.
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Target Audiences for ACS Compass Handbooks
General Users
Businesses
High School Teachers
Media
Congressional Staff
State & Local Governments
Federal Agencies
Researchers
Rural Areas
PUMS Users
American Indians / Alaska Natives
PRCS (in Spanish)
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Information about the American Community Survey
www.census.gov/acs/Subscribe to the
ACS Alert
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Organization of ACS Data in the American FactFinder (AFF)
1. Datasets (ACS, Census)
2. Data year(s)
3-year data products are the default
1-year and 3-year data products distinguished
3. Data products
4. Specific tables or maps
Assistance links highlighted
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Journey-to-Work ACS Data Products
Data products and prefixes B Base Detailed Table
C Collapsed Detailed Table
S Subject Table
R Ranking Table (single-year only)
GCT Geographic Comparison Table
M Thematic Map
Commuting products are numbered “08” Example: B08xxx is a Base Table on commuting
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Journey-to-Work ACS Data Products
Detailed Table examples (B08xxx / C08xxx):Means of transportation by worker characteristics
Travel time by time leaving home
Place of work for metropolitan, micropolitan, and non-metro/micro levels
Vehicles available in household
Majority of tables available at both residence geography (B081xx, B082xx, B083xx) &
workplace geography (B084xx, B085xx, B086xx)
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Journey-to-Work ACS Data Products
Subject Tables same information as Detailed Tables but more user friendly format
Examples (S08xxx):Commuting characteristics by sex
Means of transportation to work by selected characteristics
- at residence geography
- at workplace geography
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Journey-to-Work ACS Data Products
Ranking Tables rank states for one measure
(R08xxx):Mean travel time to work
Percent of workers who traveled to work …
by car, truck, or van alone
by carpool
by public transportation
Percent of workers who worked outside county of residence
For one-year data only
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Journey-to-Work ACS Data Products
Geographic Comparison Tables cover same measures as Ranking Tables but for more geographies
Examples (GCT08xxx): Mean travel time to work for counties by U.S. state
Percent of workers who traveled to work by carpool by place by U.S. state
Percent of workers who worked outside county of residence by urban / rural, metropolitan and micropolitan area status
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Journey-to-Work ACS Data ProductsThematic Maps allow users to design own
maps of same measures as Ranking Tables(M08xxx)
Can determine… Data classes: number and breaksBoundaries and features Level of geography
- State- County - Congressional district - Metropolitan/ micropolitan statistical area- Public Use Microdata Area (PUMA)
Data Products- American FactFinder factfinder.census.gov
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Select Dataset and Product Type
Organized by dataset then by
data product
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List all Tables- Select “08” Products
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Select Geography
Many ways to select geography
Geography is hierarchical: First select type of geography,then specific area.
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Subject Table- Example (S08xxx)
Click “Data Sets” to change data product
Change year,
geography, subject
table
Print, download, save or load a query
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Detailed Table- Example (B08xxx/C08xxx)
Can select multiple areas for detailed tables
Select geo type, e.g. urban, rural, metro, principal city
Change to collapsed version
Can select multiple detailed tables too (scroll down)
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Detailed Tables- Geo Components (down to state only)
Click Next to see other geographies selected
Download to get all geographies and tables at once
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Download- Example
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Ranking Table- Example (single year only)
Can sort by rank or by state
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Geographic Comparison Table- Example (GCT08xxx)
Geographies or geo componentswithin nation or state only
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Thematic Map- Example (M08xxx)
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Thematic Map- Options
Statistical significance view
- Select a geography
- Displays all areas that are statistically significantly different from the selected geography
- Can save as .PDF file under “download” menu
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Other Options in American Factfinder
Can create “Custom table” from the detailed tables
Data Download Center - Download selected ACS tables for all available geographies at one time
Can “Download PUMS data” file for microdata
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Data Download Center
Download large amounts of ACS dataGeographic units
Total U.S. StatesCountiesPlacesCBSAs (Metro and Micro Areas)
Congressional Districts
All areas meeting minimum population threshold
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Data Download Center
ACS Tables (Selected)Base / Detailed tables Data profilesSubject tables
Choose up to 50 tables at one timeDownload .zip file consisting of .txt files
README file Geographic identifiersData- estimate and 90% MOE for each cell, all tables
Files pipe-delimited, can upload to Excel
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Data Download Center- Example
On American FactFinder …Data Sets page on upper right
…or left side bar
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Data Download Center- Example
Select Dataset
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Data Download Center- Example
Select one geographic
level
Select data product type
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Data Download Center- Example
Select up to 50 tables and ‘Add’
Click ‘Next’ to get to ‘Start Download’ then download a .zip file
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Data Download Center- Example
.Zip file includes areadme file on data values, geographic identifiers, and
data file(s) Open data file in Excel as ‘Delimited’ by pipe: |
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U. S. Census Bureau
Melissa Chiu, CTPP Coordinator
Journey-to-Work & Migration Statistics Branch
Housing and Household Economic Statistics
301-763-2421, -2454
www.census.gov/population/www/socdemo/journey.html