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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

melissa.c.chiu@census.gov

www.census.gov/population/www/socdemo/journey.html