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Data Collection and Analysis in the U.S. Demographic System

John F. Long

www.usademography.com

Dimensions of Data Collection

•Geography –

• Nation• State• County• City• Tract• Block• Housing unit

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• Time Period –

• Decennial• Annual• Monthly

• Characteristics –

• Demographic• Social• Economic

Dimensions of Data Collection

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Major Data Collection Systems

•2010 Census•Vital Event Registration •Administrative Data•American Community Survey (annual)•Monthly Labor Force Survey •Specialized Household Surveys

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Dimensions of Data Collection

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Data Collection Types

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Data Collection

Geography Characteristics Time

2010 Census X XVital Events &Administrative Records.

X X

Household Surveys

X X

American Community Survey

X X X

Dimensions of Data Collection

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2000 Decennial Census – (geography by characteristics)

In Census 2000, the census used 2 forms

1.“short” form – asked for basic demographic and housing information, such as age, sex, race, how many people lived in the housing unit, and if the housing unit was owned or rented by the resident

2.“long” form – collected the same information as the short form but also collected more in-depth information such as income, education, and language spoken at home

Only a small portion of the population, called asample, received the long form.

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2010 U.S. Decennial Census (geography by selected characteristics)•Design Features

• Basic Demographic Data Only• Hand-held GPS address canvassing• Mailed Census Forms• Non-response follow-up

•Functions• Political Apportionment / Redistricting• Fund Allocation and Policy Implementation• Base for Estimates and Surveys

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2010 Census Timeline

Spring 2009: Census employees go door-to-door to update address list nationwide.

February – March 2010: Census questionnaires are mailed or delivered to households.

April 1, 2010: Census Day

April – July 2010: Census takers visit households that did not return a questionnaire by mail.

December 2010: By law, Census Bureau delivers population counts to President for apportionment.

March 2011: By law, Census Bureau completes delivery of redistricting data to states.

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GPS Address Canvassing

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Mail-out Census Forms

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2010 Census Questionnaire

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7 Census Questions per person

-Name

-Sex

-Relationship

-Date of Birth

-Race

-Hispanic Ethnicity

-Housing Tenure14

Census 2010 Questions (part 1)

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Census 2010 Questions (part 2)

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Census 2010 Questions (part 3)

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Processing Forms

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Non-Response Follow-up Personal Interview

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Vital Events and Administrative Data --(geography by time)

Annual data on Births and Deaths for Counties from Vital Events Registration

Annual data on migration from administrative records

-tax returns

-immigration registration

-housing construction

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Household Surveys-(characteristics by time)

National data on specific topics from national household surveys

- monthly unemployment

- government program participation

- school enrollment

- etc.

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Increasing Rate of Change of Social and Demographic Factors

•Small Area Data Previously Available only Every 10 Years (census)•National Survey provided data only at the level of states or above•American Community Survey will provide more frequent data for small areas

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American Community Survey-(geography by characteristics by time)

•Based on Results of Latest Census•Controlled to Annual Independent Estimates•Provides Annual detailed Data for Demographic, Social , and Economic Characteristics for large areas•Provides 5-year detailed data for the smallest geographies

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2010 Census and American Community Survey

•2010 Census will focus on counting the U.S. population

•The sample data are now collected in the ACS

•Puerto Rico is the only U.S. territory where the ACS is conducted

•2010 Census will have a long form for U.S. territories such as Guam and U.S. Virgin Islands

•Same “short form” questions on the ACS

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American Community SurveyContent

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American Community Survey Social Characteristics

• Education• Marital Status• Fertility• Grandparent Caregivers• Veterans• Disability Status

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• Place of Birth• Citizenship• Year of Entry• Language Spoken

at Home• Ancestry / Tribal

Affiliation

American Community Survey Economic Characteristics

• Income• Benefits• Employment Status• Occupation• Industry• Commuting to Work• Place of Work

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American Community Survey Housing Characteristics

• Tenure• Occupancy & Structure• Housing Value• Taxes & Insurance• Utilities• Mortgage/Monthly Rent

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American Community Survey Demographic Characteristics

• Sex• Age• Race• Hispanic Origin

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American Community Survey Methodology

•Sample includes about 3 million addresses each year

•Three modes of data collection– mail– phone– personal visit

•Data are collected continuously throughout the year

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Telephone Non-Response Follow-up

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American Community SurveyTarget Population

•Resident population of the United States and Puerto Rico

– Living in housing units and group quarters

•Current residents at the selected address

– “Two month” rule

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American Community SurveyGroup Quarters

• Place where people live or stay that is normally owned or managed by an entity or organization providing housing or services for the residents.

• 2 categories of group quarters:

– Institutional– Non-institutional

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American Community Survey Period Estimates

•ACS estimates are period estimates, describing the average characteristics over a specified period

•Contrast with point-in-time estimates that describe the characteristics of an area on a specific date

•1-year, 3-year, and 5-year estimates will be released for geographic areas that meet specific population thresholds

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American Community Survey Data Products Release Schedule

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Data Product Population Size Data released in: of Area 2007 2008 2009 2010 2011

1-Year Estimates 65,000+ 2006 2007 2008 2009 2010for Data Collected in:

3-Year Estimates 20,000+ 2005-2007 2006-2008 2007-2009 2008-2010for Data Collected in:

5-Year Estimates All Areas* 2005-2009 2006-2010for Data Collected in:

* Five-year estimates will be available for areas as small as census tracts and block groups.Source: US Census Bureau

American Community SurveySimilarities with Census 2000

•Same questions and many of the same basic statistics

•5-year estimates will be produced for same broad set of geographic areas including census tracts and block groups

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American Community SurveyKey Differences from Census 2000

•Beginning in 2010, data for small geographic areas will be produced every year versus once every 10 years

•Data for large and mid-sized areas are available now and data for small areas will be available in December 2010

•Census 2000 data described the population and housing as of April 1, 2000 while ACS data describe a period of time and require data for 12 months, 36 months, or 60 months

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American Community SurveyKey Differences from Census 2000

•The goal of ACS is to produce data comparable to the Census 2000 long form data

•These estimates will cover the same small areas as Census 2000 but with smaller sample sizes

•Smaller sample sizes for 5-year ACS estimates results in reductions in the reliability of estimates

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Data Analysis Issues

• Define Analytical/Policy Issue

•Choice of Data Collection Types

•Integrating Multiple Data Collection Results: example of migration

•Emerging Issues in the U. S. and Measurement Strategies 39

Data Analysis from Different Data Dimensions

Example: Migration Analysis

2000 Census data provided data for a 5-year period

No migration data from 2010 Census

Alternatives –

- CPS data

- Administrative records

- American Community Survey41

Alternative Migration Data Sets

Previous Censuses – geography by characteristics

Administrative Records – geography by time

Household Surveys – characteristics by time

American Community Survey (ACS) – geography by characteristics by time

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ACS Comparability Issues

-5-years of annual ACS data is not equivalent to a migration period of 5-years (return and repeat migration)

-Small geographic areas require use of multi-year averages

-Sampling error can mask demographic change – especially for net migration.

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Comparison of 1-year Migration and Mobility Rates from the American Community Survey and the March Current Population Survey:

2005, 2006, and 2007

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Migration rates in percentACS in HHs CPS ACS ACS in HHs CPS ACS ACS in HHs CPS

Total Movers 16.1 13.9 16.8 15.9 13.7 15.9 14.9 13.2 Intracounty Movers 9.9 7.9 9.9 9.7 8.6 9.4 9.2 8.6 Total Domestic Migrants 5.6 5.3 6.9 5.6 4.7 6.5 5.2 4.2 Intrastate Migrants 3.1 2.7 3.6 3.1 2.8 3.4 2.9 2.5 Interstate Migrants 2.5 2.6 2.7 2.5 2.0 2.5 2.3 1.7 International Migrants 0.6 0.6 0.6 0.6 0.4 0.6 0.5 0.4

Total, 1 and over (in 1,000's) 284.4 287.1 295.3 287.3 289.8 297.5 289.4 292.7

2005 20072006

Conclusion: ACS rates are 10 to 20 % higher than CPS rates.

Comparison of 1-year Net Migration from the 2007 American Community Survey and the 2007

Intercensal Population Estimates: Selected Areas in Michigan

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Geographic Area 2007 Pop. In Migration Out Migration Net Migration Rate

Michigan ACS (pop. 1 & over) 9,945.3 131.3 209.8 -78.5 -0.79%margin of error 4.3 7.7 12.0Estimates (total pop.) 10,071.8 -94.4 -0.94%

Detroit-Warren- ACS (pop. 1 & over) 4,410.6 160.6 228.6 -68.0 -1.54% Livonia,MSA margin of error 3,167.0 12.3 17.3

Estimates (total pop.) 4,467.6 -58.1 -1.30%

Wayne County ACS (pop. 1 & over) 1,959.6 50.8 96.8 -46.0 -2.35%margin of error 2.3 7.7 12.2Estimates (total pop.) 1,985.1 -40.8 -2.06%

(interstate migration)

(migration between counties)

(migration between counties)

Conclusion: ACS net migration numbers and rates are similar to intercensal estimates.

Conclusion

---Multiple data collection methods in the U.S. demographic system– particularly the new American Community Survey – provide flexibility and new insights to social and demographic change

---However, comparing results across systems requires care and an understanding of methodological differences.

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