panel on statistical methods for measuring the group quarters population in the acs apdu paul r....

Panel on Statistical Methods for Measuring the Group Quarters

Population in the ACS

APDU

Paul R. VossUNC at Chapel Hill

& Panel Chair

APDU 2010 Annual ConferenceSeptember 21, 2010

Committee on National Statistics (CNSTAT)

• Established in 1972 at the National Academies to improve the statistical methods and information on which public policy decisions are based

• Carries out studies to foster better measures of the economy, crime, poverty, and other domains

• Evaluates ongoing statistical programs and coordination of the decentralized U.S. federal statistical system

• Activities generally requested and sponsored by specific federal statistical agencies

APDU

APDU

Some recent CNSTAT reports addressing census & ACS topics

• W.A.V. Clark, UCLA• S. Copella, PA SDC• D.Dolson, Statistics

Canada• R. Folsom, RTI

International• R. Harter, NORC

• S. Heeringa, University of MI

• J. Salvo, NYC Dept. of City Planning

• R. Valliant, Univ. of MD• P. Voss, UNC (Chair)• K. Marton, CNSTAT

(Study Director)

APDU

Panel on Statistical Methods for Measuring the Group Quarters Population in the ACS

• Duration: Approximately 18-20 months– 6 meetings– workshop & other activities– interim & final report

• Charge: In depth review to advise Census Bureau on measuring GQ in ACS– statistical & operational issues

• sample frame• sampling• weighting & population controls

– data use/user issues• who?• how?• Alternatives?

APDU

Panel on Statistical Methods for Measuring the Group Quarters Population in the ACS

We need to know…

• Why? Basis of objection? If this is you or your organization… we really want to hear from you!

• Note:– I’m asking this question in my role as chair of the Panel

– The Panel has not yet discussed this question in any serious way

• But we recognize that there are some very serious issues here…

APDU

WHO WOULD OBJECT IF OUR PANEL RECOMMENDED TO THE CENSUS BUREAU THAT SOME OR ALL GQ SUBPOPULATIONS BE PLACED “OUT-OF-SCOPE” IN THE ACS?

Issues…• Early indications suggest that there are few users of

the ACS GQ data, per se• Why would this be?

– not much data available yet from ACS– the eventual ACS data for GQ populations is going to be pretty thin– 2010 Census data showing GQ populations by type and age-sex-race

characteristics may be sufficient – there are many other special surveys of GQ populations designed to

meet federal data & programmatic needs– there are problems with the ACS GQ data

• But what happens if the GQ were not included in the total population universe? Let me reframe the Q:

APDU

WHO WOULD OBJECT IF SOME OR ALL GQ POPULATIONS WERE REMOVED FROM THE TOTAL BASE POPULATION FOR ACS DATA

ON POPULATION CHARACTERISTICS?

Let’s back up for just a moment

…places where people live or stay, in a group living arrangement, that are owned or managed by an entity or organization providing housing

and/or services for the residents

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What are “group quarters”?

7 main types of GQ• Correctional facilities for adults• Juvenile facilities• Nursing facilities/skilled nursing facilities• Other health care facilities• College/university student housing• Military quarters• Other noninstitutional facilities

APDU

3 principal types of GQ comprise most of GQ universe

• College/university student housing (25%)

• Nursing facilities/skilled-nursing facilities (23%)

• Correctional facilities for adults (19%)

• Full GQ population approximately 8 million persons (~3% of total population)

APDU

Background• The census enumeration and the separate

identification of persons living in irregular housing dates from 1850

• GQ: part of the census sample data collection and reporting since 1940

• Comprehensiveness of tabulations and quality of the sample data has varied from census to census

• GQ in ACS monthly sample since 2006

APDU

Why retain GQ data in the ACS?• Because the Bureau promised!

• Since 1970, the long from sample has provided content rich & statistically very strong data for the full U.S. population; important programmatic needs

• Because the ACS GQ data, in some respects, are much improved over the 2000 Census long form GQ data

– e.g., significantly reduced levels of item imputation

• Because some data users may need these data

– some data users may need certain GQ data for programmatic purposes

– many data users want the ACS universe to include the total population

– we want to hear from those users

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Why consider dropping some or all GQ data from the ACS?

• The need for sample GQ data is not very well documented

• Not much is going to be published anyway

– But what about the PUMS data?

• There are problems with the data:

– Imputation rates still uncomfortably large– The separation of the sample controls from the census enumeration

means that controls are estimate-based– Small populations; smaller samples; “zero” GQ problems

• Some small, difficult-to-survey, GQ populations have already been dropped from the ACS sample

• Are there appropriate cost-benefit issues? GQ considerably more expensive than HH portion of ACS (GQ: $89 per person interview; HH: $13 per person interview)

APDU

We really want to hear from you!• You may write to us directly expressing

your concerns or opinions– Paul Voss

• paul_voss@unc.edu

– Krisztina Marton• KMarton@nas.edu

• Survey of data users

• Data user conference

• It’s important!

APDU