B. COLLECTION OF INFORMATION EMPLOYING STATISTICAL
METHODS
Describe (including a numerical estimate) the potential respondent universe and any sampling or other respondent selection method to be used. Data on the number of entities (e.g., establishments, State and local government units, households, or persons) in the universe covered by the collection and in the corresponding sample are to be provided in tabular form for the universe as a whole and for each of the strata in the proposed sample. Indicate expected response rates for the collection as a whole. If the collection had been conducted previously, include the actual response rate achieved during the last collection.
The December Supplement is conducted in conjunction with the CPS, for which the universe is approximately 120 million households, comprising the non-institutionalized civilian population of the United States. From this universe, a stratified, clustered, probability sample of approximately 72,000 household addresses is selected each month. Of these, an average of 58,934 households were eligible for interview (i.e., were currently residences) in 2009 and 2010, and 53,935 (92 percent) complete the core labor force survey. All households completing the core labor force questions will be asked to answer the Supplement questions applicable to their household. Based on responses in the December 2009 and 2010 Food Security Supplements, approximately 45,134 households (84 percent of those that complete the core labor force interview) are expected to respond to the Supplement. The questions are intended to be asked of the person most knowledgeable about food shopping and meal preparation in the household. If one person is most knowledgeable about shopping for food but another is most knowledgeable about meal preparation, the person most knowledgeable about meal preparation is interviewed. If there is no one person in the household who is most knowledgeable about the food that is bought or eaten, or if that person is not available for interview, the labor force respondent is encouraged to answer the questions the best they can.
The response rate to the core labor force survey (average 2009 and 2010) was 92 percent. The response rate to the Supplement was 77 percent (92 percent x 84 percent). However, the supplement is reweighted to national control totals and to match the income profile of the core respondents, so food security statistics are less biased by non-response than would be the case without information from the core survey about the supplement non-respondents.
2. Describe the procedures for the collection of information including:
Statistical methodology for stratification and sample selection,
Estimation procedure,
Degree of accuracy needed for the purpose described in the justification,
Unusual problems requiring specialized sampling procedures, and
Any use of periodic (less frequent than annual) data collection cycles to reduce burden.
The collection is a supplemental interview associated with the December CPS. The CPS sample is a stratified clustered address-based sample. Census Bureau field staff conduct about one-third of interviews face-to-face in respondents homes and the remainder by telephone, using computer assisted interviewing technology. Weights for the core (labor force) CPS are calculated beginning with a basic weight for each person, which represents the probability of selection for the survey. The basic weight is adjusted for special sampling situations and failure to obtain interviews from eligible households. A two-stage ratio estimation procedure adjusts the sample population to the known distribution of the entire population by age, gender, race, and Hispanic ethnicity. The Census Bureau also calculates person and household weights for use with the food security supplement data that take into account nonresponse to the supplement by households that respond to the core CPS.
Attachment F contains an overview of the CPS sample design and weighting methodology. A detailed description is available in Current Population Survey Design and Methodology: Technical Paper 66, available on the Census Bureau web site at: http://www.census.gov/prod/2006pubs/tp-66.pdf . The statistical properties of these supplemental items will be similar to those associated with the basic CPS items.
The Census Bureau provides replicate weights to support balanced repeated replication (BRR) variance estimates. Procedures for estimating variances using these weights are described in Census Bureau guidance available at: http://thedataweb.rm.census.gov/ftp/cps_ftp.html#cpsrepwgt. In 2010, the standard error for the estimated national percentage of food insecure households (14.5 percent) was 0.196 percentage points. For the estimated percentage of households with children in which children experience very low food security (0.98 percent), the standard error was 0.089 percentage points. The latter measure is a goal in the USDA strategic plan and both measures are objectives in the Health and Human Services Healthy People 2020 initiative. The sampling errors are sufficiently small to support credible monitoring of progress toward these goals.
3. Describe methods to maximize response rates and to deal with issues of non-response. The accuracy and reliability of information collected must be shown to be adequate for intended uses. For collections based on sampling, a special justification must be provided for any collection that will not yield "reliable" data that can be generalized to the universe studied.
Response rates and data accuracy for the CPS are maintained at high levels by the U.S. Census Bureau through advance notification of respondents, interviewer training and standardization, computerized tracking of call attempts and callbacks, computerized interviewing, internal consistency edits in the computerized instrument and in data editing, and close monitoring of these data. ERS expects response rates consistent with the December 2009 and 2010 surveys.
ERS conducts psychometric assessment of the food security response data using statistical methods based on Item Response Theory to assess quality of the food security response data nationally and in key subpopulations. This ensures that food security prevalence statistics are comparable over time and across key subpopulations.
Beginning in December 2012, Census Bureau staff who conduct CPS Food Security Supplement interviews in Spanish will be provided with a standardized translation of the questions that are used to determine households’ food security status in order to minimize bias in comparing food security statistics between Hispanic and non-Hispanic households. Before the December 2013 survey, ERS plans to provide a standardized Spanish translation of the entire Supplement. Prior to 2012, interviewers translated “on the fly” when interviewing households that could only be interviewed in Spanish. The Spanish language for the entire supplement will be integrated into the computerized interview instruments as soon as the Census Bureau is able to accommodate this process.
4. Describe any tests of procedures or methods to be undertaken. Testing is encouraged as an effective means of refining collections of information to minimize burden and improve utility. Tests must be approved if they call for answers to identical questions from 10 or more respondents. A proposed test or set of tests may be submitted for approval separately or in combination with the main collection of information.
USDA has completed several tests suggested by the Committee on National Statistics Panel report of 2006. No further testing is planned in the 2013-15 period covered by this request.
5. Provide the name and telephone number of individuals consulted on statistical aspects of the design and the name of the agency unit, contractor(s), grantee(s), or other person(s) who will actually collect and/or analyze the information for the agency.
The following individuals may be consulted concerning the statistical data collection and analysis operations:
Statistical Design:
Patrick Flanagan
Demographic Statistical Methods Division
U.S. Census Bureau
(301) 763‑4290
Data Collection/ Survey Design:
Lisa A. Clement
Demographic Surveys Division
U.S. Census Bureau
(301) 763-5482
Analysis of Food Security Data
Mark Nord
Food Assistance Branch
Economic Research Service, USDA
(202) 694-5433
Attachments
Proposed December 2013 Food Security Supplement Questions
Copy of Federal Register Notice regarding this collection
Comment received in response to Federal Register notice
CPS Advance Letter
Confidentiality Brochure
Overview of CPS Sample Design and Methodology
Summary of Studies Exploring Potential Technical Enhancements to the Methods USDA Uses to Measure Household Food Security in the United States
Improving Communication of Food Security Statistics: Common Misinterpretations and USDA Attempts to Prevent Them
| File Type | application/msword |
| Author | JHESSION |
| Last Modified By | %USERNAME% |
| File Modified | 2012-12-05 |
| File Created | 2012-12-05 |