Census 2010: Data, Measurement and Access (over time, space, and surveys) Thursday, July 28, :30am

Issues in using multiple sources “If you want to measure change, don’t change the measure”. -Duncan “You can never step into the same river; for new waters are always flowing on to you.” -Heraclitus “To use the data …. you’ve got to be able to find it. - Vogt

If you want to measure change, don’t change the measure Statistics vs. data Differences and identities – When are things the same or different? – And when do we want them to be? Who gets asked? What gets asked? How are they asked? How are the responses reflected in what you get?

If you want to measure change, don’t change the measure ACS vs. ACS ACS vs. Decennial Censuses Decennial vs. Decennial Other Surveys Aggregate vs. Microdata

If you want to measure change, don’t change the measure ACS vs. ACS

Who gets asked? ACS vs. ACS Biggest issue for ACS Users is if you want to go back prior to was the first full implementation of the household sample was the first year in which the group quarters sample was added.

What gets asked?

Most content changes in 2008, 2009 What gets asked?

2008 New questions on marital history, health insurance coverage, and veterans service-connected disability status Complete revision of the disability questions Modifications to the school enrollment and educational attainment questions to collect more detailed information on grade enrolled and level of attainment. Modifications to the relationship, year of naturalization, employment, and Food Stamps questions 2009 Addition of a question on bachelor’s degree field 2013 Parental Place of Birth, Household Computer & Internet Use Revisions to questions on veterans status and period of service, Food Stamps, wage and salary income, interest and dividend income, and cash public assistance What gets asked?

How are they asked ACS vs. ACS Multi-mode, generally comparable, similar NRFU

How are responses reflected in what you get? ACS vs. ACS Aggregate data will differ by geography (1 year/3 year/5 year products) In general – don’t mix and match if doing comparisons. Choose shortest time frame consonant with desired geography and MOE. Avoid comparing overlapping time frames (e.g vs ). Geographies defined as of Jan 1 of final year in release. For both aggregate and microdata, geographies will shift at decennial.

A Compass for Understanding and Using the ACS… … for General Public, PUMS Users, Congress, Media, Business Community, Federal Agencies, State and Local Governments, Teachers, Researchers, User of American Indian Data, Users of Rural Data……

Residence Rules□ Usual place of residence – Self identification of where you live most of the year. College students are supposed to be counted at their college address. □ Current Residence – Counted at the sampled address if lived there most of the time in the last TWO MONTHS. College students might be counted at parent’s house during the later summer months. □ Does not capture seasonality or second home location. □ This will have a greater impact on areas with large seasonal populations such as college and resort communities. □ Seasonal destination areas may have population counted that would have lived elsewhere in the April 1, Census. ACS vs. Census: Who gets asked

The number of households from which the bureau received information from “proxies”—neighbors, building managers, or others—rather than direct information, increased from 17% in 2000 to 22% in Proxy Respondents□ Allowed - People living outside the address (landlords, neighbors, etc.) are allowed to provide information. □ NOT Allowed - ONLY people living at the address can answer the questions. ACS vs. Census: Who gets asked

Collection Procedures Non- Response Follow-up □ Primarily personal visit by short-term, moderately trained employees, being paid a relatively low wage for the area. □ Conducted by long-term, highly-trained employees, being paid reasonably well for the area. □ Emphasis on counting number of people at address. □ Telephone follow-up in second month if possible. Personal visit in third month usually to 1/3 of addresses not responding. □ Emphasis is on collecting characteristics of individuals in the household. Impact: In general, greater item response rates in ACS. Item allocation rates vary from more than 20% for property insurance cost, 20% for some or all income items, 17% for real estate taxes, 16% for year of naturalization, 10% for property value, 9% for year of entry, 6% for occupation, 4% language, 1% age, 0.2% sex. Allocation rates for ACS are substantially lower (about half) than for the 2000 Census. ACS vs. Census: How are they asked?

Income understated on ACS relative to Decennial School Enrollment reference period could stretch from 6 wks to 7 months for decennial. Reference Period□ Income: Last Calendar Year □ Income: Last 12 months □ School Attendance : Since February 1 □ School Attendance : Last 3 months □ Utility Costs: Last Calendar Year □ Utility Costs: Last Month ACS vs. Census: Reference periods

WeightingSample Data Weighted to 100% counts (for April 1) Sample data weighted to Population Estimates for each year as of July1 (at the county (or contiguous-county group in the case of very small counties) level by age, race, sex and Hispanic origin ACS vs. Census: How are responses reflected in what you get?

ACS vs. Census Specific Content comparability vs 2000 Census by topic area

Similar kinds of comparability guidance from decennial technical documentation

Decennial vs Decennial: What gets released? Summary Files products 1960 and earlier: Mary Ellen Bogue files (Tracts – 1940,1950,1960), county/state/national data NHGIS, Social Explorer (Tract), UV Fisher (county) “one-offs”

Decennial vs Decennial: What gets released? Summary Files products Historical Statistics of the United States (Millenial Edition)

Decennial vs Decennial: What gets released? Summary Files products Print Volumes

Decennial vs Decennial: What gets released? Summary Files products Generally separate products for: 100% vs sample data detailed age and race widely used socio-demographic iterated race/ethnicity/ancestry “special” tabulations (school districts, EEO, transportation) Also, geographic detail files; MATILDA, MEDList (1970), MARF (1980), MABLE/GEOCORR (1990, 2000).

Other Surveys: Current Population Survey (March) American Community SurveyCurrent Population Survey Geography All Census geographies, but product type differ by geographic entity's size.Nation, regions, and states for selected characteristics. Sample Size About 3 million addresses per year. Data are collected from about one-twelfth of the sample each month.Annual sample size is about 100,000 addresses. Data Collection Method Mail, telephone, and personal-visit interviews for the 50 states, the District of Columbia, and Puerto Rico. (The Puerto Rico Community Survey began collecting data in 2005.) About half the responses are obtained by mail. The ACS is a mandatory survey. Telephone and personal-visit interviews for the 50 states and the District of Columbia. The CPS is a voluntary survey. Residency Status The ACS includes a person at the address where they are at the time of the survey if they have been there, or will be there, more than 2 months, whether or not they have a “usual residence elsewhere.” The CPS sample unit’s householder (one of the people in whose name the unit is rented or owned) must consider the unit to be their place of usual residence (where they spend most of the time during the year) to be counted as an occupied unit, which is traditional in most censuses and housing surveys. If a family has more than one home, the interviewer has to determine if the sample unit is their usual residence. Population Universe The 2005 ACS included only the household population. This universe includes both the civilian and military population in households. The group quarters population consists of the institutionalized and the noninstitutionalized, and were added in 2006 and later. The weighting is controlled to population estimates as of July 1. The CPS includes the civilian noninstitutionalized population. This universe includes civilians in households, people in noninstitutional group quarters (other than military barracks) and military in households living off post or with their families on post (as long as at least one household member is a civilian adult). The universe excludes other military in households and in group quarters (barracks), and people living in institutions. The weighting is controlled to population estimates as of March 1. Time Period Covered ACS collects data continuously thoroughout the year and the reference period for select questions (like income and the number of weeks worked) is the 12-month period prior to the response month. Monthly interviews conducted from February to April 2006 ask about calendar year 2005 income. Length and Detail of Questions Using a series of eight questions, the ACS asks about money income, plus one type of noncash benefit (food stamps) during the previous 12 months. CPS asks a series of questions about more than 50 sources of income, including questions about the amount of several noncash benefits such as food stamps and employment- related health insurance, during the previous calendar year.

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