But what about the ACS?But what about the ACS?

What is the American What is the American Community Survey?Community Survey?

Replacement of the Long FormReplacement of the Long Form

Continuous Survey MethodologyContinuous Survey Methodology

Conducted MonthlyConducted Monthly

According to the Census Bureau According to the Census Bureau The ACS is…The ACS is…

A large, continuous demographic surveyA large, continuous demographic survey• Produces annual and multi-year estimates of Produces annual and multi-year estimates of

the characteristics of the population and the characteristics of the population and housinghousing

• Produces Produces characteristicscharacteristics, , not not a populationa population countcount

• Produces information for small areas Produces information for small areas including tracts, block groups and including tracts, block groups and population subgroups - updated every yearpopulation subgroups - updated every year

• Key component of reengineered 2010 Key component of reengineered 2010 censuscensus

ACS FactsACS Facts

About 1 in 40 About 1 in 40 Households Sampled per yearHouseholds Sampled per year

250,000 Households Sampled 250,000 Households Sampled per monthper month

Same Transportation questions Same Transportation questions as 2000 Long Formas 2000 Long Form

Decennial Long Form is History, Kaput, Gone!Decennial Long Form is History, Kaput, Gone!

But why change and have But why change and have an ACS?an ACS?

Eliminate the Census Long Form for Eliminate the Census Long Form for 2010 and Thereafter2010 and Thereafter

Eliminate the peak in Congressional Eliminate the peak in Congressional fundingfunding

Eliminate the peak in hiring andEliminate the peak in hiring and training training Census takersCensus takers

How does the ACS work?How does the ACS work?

Three Methods of Data CollectionThree Methods of Data Collection

1. Mail1. Mail Self-administered mail-out/mail-backSelf-administered mail-out/mail-back

2. Telephone2. Telephone Computer Assisted Computer Assisted Telephone Interviewing (CATI)Telephone Interviewing (CATI)

3. Personal Visits3. Personal Visits Computer Assisted Computer Assisted Personal Interviewing (CAPIPersonal Interviewing (CAPI) ) 1:31:3

When will it start?When will it start?It already hasIt already has

American Community Survey Data Release Timetable

Type of Data

Population

Size of Area

Data for the Previous Year Released In the Summer of:

2006 2007 2008 2009 2010 2011 2012+

Annual Estimates

65,000+

3-year averages

20,000+

5-year averages

Down to Census Tract and Block Group

1

Example 1: Percent Foreign Born Population Areas with 65,000+ population

2005 2006 2007 2008 2009 2010

Single-year estimates 20.0 21.2 23.3 28.6 32.6 35.1

3-year estimates (2005 – 2007) 21.5

3-year estimates (2006 – 2008) 24.8

3-year estimates (2007 – 2009) 28.6

5-year estimates (2005 – 2009) 25.9

3-year estimates (2008 – 2010) 32.2

5-year estimates (2006 – 2010) 28.9

Aug. 2008Aug. 2008

Aug. 2010Aug. 2010In August of In August of 2006 you got 2006 you got

2005 data2005 data

3

Example 1: Percent Foreign Born Population Areas with population between 20,000 and 65,000

2005 2006 2007 2008 2009 2010

3-year estimates (2005 – 2007) 21.5

3-year estimates (2006 – 2008) 24.8

3-year estimates (2007 – 2009) 28.6

5-year estimates (2005 – 2009) 25.9

3-year estimates (2008 – 2010) 32.2

5-year estimates (2006 – 2010) 28.9

Aug. 2008Aug. 2008

April 1 August Dec. April 1 August Dec. (PL 94-171) (PL 94-171)

5

Example 1: Percent Foreign Born Population Areas with less than 20,000 population

2005 2006 2007 2008 2009 2010

5-year estimates (2005 – 2009) 25.9

5-year estimates (2006 – 2010) 28.9

Aug. 2010Aug. 2010

20102010

Decennial CensusDecennial Census ACSACS

Sample: 1 in 6 Hhlds Sample: 1 in 6 Hhlds

(17% Sample)(17% Sample)

Sample: 1 in approx 40 Sample: 1 in approx 40 households each yearhouseholds each year

(2.5%/yr 12.5% @ 5 yrs)(2.5%/yr 12.5% @ 5 yrs)

Time reference: April 1, Time reference: April 1, 2000 or April 1, 20102000 or April 1, 2010

(Last Week)(Last Week)

Time reference: Time reference: Continuous including all Continuous including all 12 months12 months

One time data collection One time data collection every 10 yearsevery 10 years

Requires accumulation Requires accumulation over multiple years for over multiple years for small area reportingsmall area reporting

Main differences between Census Long Form Main differences between Census Long Form and ACSand ACS

Some Emerging IssuesSome Emerging Issues

People might be counted twicePeople might be counted twice, e.g. once at , e.g. once at summer cabin and once at a “permanent home”. summer cabin and once at a “permanent home”. Or once at university and once at parent’s home.Or once at university and once at parent’s home.

Areas with seasonal populationsAreas with seasonal populations, e.g. due to , e.g. due to “snow bird” migration, and due to school “snow bird” migration, and due to school enrollments, with housing occupancy that varies enrollments, with housing occupancy that varies from 95% to 40% might show up as 80%.from 95% to 40% might show up as 80%.

Mail back rates from Minority Mail back rates from Minority populations are significantly lowerpopulations are significantly lower

Source: C2SS test

Tracts with 75% or more of Tracts with 75% or more of a population reporting…a population reporting…

% of mail-% of mail-backsbacks

WhiteWhite 60.5%60.5%

African AmericanAfrican American 34.9%34.9%

American Indian/Alaska American Indian/Alaska Native Native

16.6%16.6%

AsianAsian 58.6%58.6%

HispanicHispanic 34.2%34.2%

Different Non Response Follow-up Different Non Response Follow-up rates based on mail back returnsrates based on mail back returns

That is, in areas with low mail-That is, in areas with low mail-back returns, a higher NRFU back returns, a higher NRFU rate will be implementedrate will be implemented

Thus, standard errors will be Thus, standard errors will be more consistent across more consistent across neighborhoodsneighborhoods

Sample ErrorSample Error is larger because the number of is larger because the number of census forms collected each year are smaller. census forms collected each year are smaller.

Changes of plus or minus 2% may be due to Changes of plus or minus 2% may be due to Sample Sample ErrorError and do not reflect measurable change. and do not reflect measurable change.

Understanding Sample ErrorUnderstanding Sample Error

Statistical Significance TestsStatistical Significance Tests

Standard Error = Margin of Error / 1.65

But what about MOEs for 2000 data?But what about MOEs for 2000 data?

22 (SE(B))(SE(A))

BAZ

90%

90%

Confidence

Confidence

Comparing ACS directly to 2000 Data can be iffyComparing ACS directly to 2000 Data can be iffy

http://www.census.gov/prod/cen2000/doc/sf3.pdfhttp://www.census.gov/prod/cen2000/doc/sf3.pdf

Chapter 8: Accuracy of the DataChapter 8: Accuracy of the Data

Estimate Standard ErrorsEstimate Standard Errors

Adjust for Survey Design Adjust for Survey Design Factors - Table CFactors - Table C

Things to consider when Things to consider when trying to compare ACS directly trying to compare ACS directly

to Decennial data to Decennial data

SeasonalitySeasonality 12 months instead of "April 1") (different jobs 12 months instead of "April 1") (different jobs and workers, especially in summerand workers, especially in summer

Group QuartersGroup Quarters currently not in 2005 ACS currently not in 2005 ACS

Non-responseNon-response follow-up differencesfollow-up differences

Data collection periodData collection period ACS is very long, compared to ACS is very long, compared to

very short in decennialvery short in decennial

Sample Sizes and MOEsSample Sizes and MOEs ACS is about 1 in 40 households ACS is about 1 in 40 households compared to about 1 in 6compared to about 1 in 6

Data Release ScheduleData Release Schedule

1-year data1-year data in 2006 in 2006 (every year thereafter) (every year thereafter)

3-year data3-year data in 2008 in 2008 ( (every year thereafter)every year thereafter)

5-year data5-year data in 2009 in 2009 ( (every year thereafter)every year thereafter)

Plus the within-year release schedulesPlus the within-year release schedules

Within-Year Data Release Within-Year Data Release Schedule for 2005 DataSchedule for 2005 Data

August 15, 2006August 15, 2006Demographic and SocialDemographic and Social CharacteristicsCharacteristics

August 29, 2006August 29, 2006Economic Characteristics; Public Use Microdata FileEconomic Characteristics; Public Use Microdata File

October 3, 2006October 3, 2006Housing Characteristics; Narrative Profiles; Housing Characteristics; Narrative Profiles; Workplace Workplace Base TablesBase Tables

November 14, 2006November 14, 2006Selected Population Profiles Selected Population Profiles

August 15th August 15th Demographic and Social Demographic and Social

August 29thAugust 29th

Economic Characteristics Economic Characteristics

and PUMS tooand PUMS too

October 3rdOctober 3rd Housing ---- Etcetera Housing ---- Etcetera

i.e. Workplace Tablesi.e. Workplace Tables

October 3rdOctober 3rd Etcetera Etcetera

… … For Workplace GeographyFor Workplace Geography

November 14November 14 Selected Population Profiles Selected Population Profiles

Where do I get ACS?Where do I get ACS?

FactFinderFactFinder

There is a lot hereThere is a lot here

Even built in significance testsEven built in significance tests

Note difference between DC and NJNote difference between DC and NJ

A place to start mining ACSA place to start mining ACS

Go to Detailed TablesGo to Detailed Tables

Check out all the TabsCheck out all the Tabs

Pick Your GeographyPick Your Geography

State . . .State . . .

Places . . .Places . . .

Then Tables . . .Then Tables . . .

Note the TabsNote the Tabs

Keyword SearchKeyword Search

““B” and “C” TablesB” and “C” Tables

Full Table – Full Table – PASSED FILTERINGPASSED FILTERING

Statistically Statistically too Smalltoo Small

Collapsed TableCollapsed Table

You Can Also Download the ResultsYou Can Also Download the Results

Download Options . . .Download Options . . .

My SelectionMy Selection

What I took homeWhat I took home

1. Resident Person Information 1. Resident Person Information

2. Resident Household Characteristics2. Resident Household Characteristics

3. Worker/Workplace Data3. Worker/Workplace Data

ACS CTPP Data ProfilesACS CTPP Data Profiles

Brand NewBrand New

CTPP Data ProductCTPP Data Product

States, Large Cities, MSAsStates, Large Cities, MSAs

Resident Person Information for…Resident Person Information for…

Mode to workMode to work

Travel Time to workTravel Time to work

Departure Time for workDeparture Time for work

Mode to work by Travel Time Mode to work by Travel Time

Mode to work by Average Travel TimeMode to work by Average Travel Time

Florida Statewide dataFlorida Statewide data

Mode to work by Vehicles AvailableMode to work by Vehicles Available

Vehicles Available in HouseholdsVehicles Available in Households

Household Size by Vehicles AvailableHousehold Size by Vehicles Available

Vehicles Available by Workers in Household Vehicles Available by Workers in Household

Persons in Households by Workers in HouseholdPersons in Households by Workers in Household

The Nation, States, All PUMAs,The Nation, States, All PUMAs,Counties and Places over 65kCounties and Places over 65k

Resident Household Characteristics for.. Resident Household Characteristics for..

Wisconsin Statewide dataWisconsin Statewide data

States, Counties andStates, Counties andPlaces over 65kPlaces over 65k

Worker / Workplace Data for…Worker / Workplace Data for…

Total Workers -- Travel Time to work -- Mode to WorkTotal Workers -- Travel Time to work -- Mode to Work

Get ACS CTPP Data Profiles Get ACS CTPP Data Profiles online or from the Class online or from the Class Workbook CD Workbook CD

On-going concerns about ACSOn-going concerns about ACS

• Will the sample be sufficientWill the sample be sufficient for small for small geographic area reporting? Will tract and BG geographic area reporting? Will tract and BG and TAZ reporting occur after 60 months of and TAZ reporting occur after 60 months of data collection?data collection?

• Will Congress continue to fundWill Congress continue to fund the survey the survey continuously, especially if CB asks for continuously, especially if CB asks for increasing budgets to meet the sample size increasing budgets to meet the sample size requirements? (or will CB decrease the requirements? (or will CB decrease the sample size, resulting in loss of small area sample size, resulting in loss of small area tabulation?) Group Quarterstabulation?) Group Quarters

What Were the Transportation What Were the Transportation Concerns in 2005?Concerns in 2005?

• Will there be flow data? Will there be flow data? Flows are in serious Flows are in serious jeopardy due to thresholds and disclosure jeopardy due to thresholds and disclosure proofing?proofing?

• Will there be a CTPP like package? Will there be a CTPP like package? Who will Who will organize it, negotiate with the CB and contract organize it, negotiate with the CB and contract with the CB. Timing of release? Cost?with the CB. Timing of release? Cost?

• Will there be TAZs? Will there be TAZs? How might they change, How might they change, what tables will be available, for what what tables will be available, for what geographies?geographies?

On-Demand Technical Assistance

$930,000

Training $625,000

Research $920,000

Data Products $2,980,000

Oversight Activities $465,000

TOTAL $5,920,003

ConsolidatedCTPP Purchase

AASHTO SCOPAASHTO SCOP Census Data Work GroupCensus Data Work Group

CTPP Technical GroupCTPP Technical Group

• Will there be flow data? Will there be flow data? Flows are in serious Flows are in serious jeopardy due to thresholds and disclosure jeopardy due to thresholds and disclosure proofing?proofing?

• Will there be a CTPP like package? Will there be a CTPP like package? Who will Who will organize it, negotiate with the CB and contract organize it, negotiate with the CB and contract with the CB. Timing of release? Cost?with the CB. Timing of release? Cost?

• Will there be TAZs? Will there be TAZs? How might they change, How might they change, what tables will be available, for what what tables will be available, for what geographies?geographies?

Current ExpectationsCurrent Expectations

NCHRP 8-48 Guidebook NCHRP 8-48 Guidebook Using the American Community Using the American Community Survey Data for Transportation Planning Survey Data for Transportation Planning ($350K) ($350K) Expected May 2007Expected May 2007

NCHRP 8-36 Project NCHRP 8-36 Project Disclosure Avoidance Techniques Disclosure Avoidance Techniques to Improve ACS Datato Improve ACS Data ($75) Expected Next Year($75) Expected Next Year

Census Geography and Census Geography and Participant Statistical Areas Participant Statistical Areas ProgramProgram — Hoping to have TAZs included — Hoping to have TAZs included

ACS Use Capacity Building ACS Use Capacity Building Peer ExchangePeer Exchange, SCOP , SCOP Working Group/FHWA, Spring 2007Working Group/FHWA, Spring 2007

ACS related activities ACS related activities currently underwaycurrently underway

Census Data for Transportation PlanningCensus Data for Transportation PlanningPreparing for the Future Preparing for the Future

Irvine, CaliforniaIrvine, CaliforniaMay 11-13, 2005 May 11-13, 2005

http://www.trb.org/conferences/censusdatahttp://www.trb.org/conferences/censusdata

Now let’s go do someNow let’s go do someStatistical Significance Testing!Statistical Significance Testing!