Documentation of the analysis file for the Alabama food stamp cash-out demonstration

275 Pages·1993·11.4 MB·English

by  Martini, Alberto P.

Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.
Contract No.: FNS 53-3198-9-52
MPR Reference No.: 7893-260
DOCUMENTATION OF THE ANALYSIS
FILE FOR THE ALABAMA FOOD STAMP
CASH-OUT DEMONSTRATION
March 9, 1993
Authors:
Alberto P. Martini
Cara S. Hendricks
James A. Sears
Submitted to: Submitted by:
U.S. Department of Agriculture Mathematica Policy Research, Inc.
Food and Nutrition Service 600 Maryland Avenue, S.W.
Office of Analysis and Education Suite 550
3101 Park Center Drive Washington, D.C. 20024
Alexandria, VA 22302
Project Director: Thomas M. Fraker
Project Director: Pat McKinney SurveyDirector: Anne B. Ciemnecki
CONTENTS
Chapter Page
I INTRODUCTION............................................. 1
II THE HIERARCHIAL DATA FILE CREATED BY NATIONAL
ANALYSTS .................................................. 3
m THE SAS PROGRAM USED TO CREATE THE
RECTANGULAR ANALYSISFILE ............................... 7
A. INPUTSECTION .......................................... 7
B. DATA TRANSFORMATION SECTION ........................ 7
1. Creating Quantity and Money Value of Food Used
for 32Food Groups ...................................... 7
2. Creating Household Size in Adult Male Equivalents .............. 9
3. Computing the Subsidy Value of School Breakfast and
Lunch................................................. 9
4. Restructuring Questions of Preference for Checks and
Stamps................................................ 11
5. Creating Person-Level Variables ............................. 11
6. Creating Household Income Variables ........................ 11
7. Imputing Missing Income Amounts... ........................ 12
8. Replacing Food Stamp, AFDC, SocialSecurity, and SSI
Amounts with Program Record Data ......................... 12
9. Computing and Merging Interview Times and Lengths ............ 12
C. OUTPUTSECTION ........................................ 13
IV THE CONTENTOF THE ANALYSISFILE ........................ 15
V IMPUTING AND EDITING OF INCOME AND FOOD
STAMPBENEFITAMOUNTS ................................... 17
A. IMPUTING MISSING INCOME AMOUNTS ..................... 17
1. Regression Imputation for Missing Earnings Amounts ............. 19
2. Regression imputation for Missing Retirement Income
Amounts ............................................... 19
3. Docum_tation of imputed Income Amounts ................... 21
B. REPLACING FOOD STAMP, AFDC, SOCIAL SECURITY,
AND SSI AMOUNTS WITH AMOUNTS FROM PROGRAM
RECORDS ............................................... 22
REFERENCES ................................................ 23
.°.
nl
CONTENTS (continued)
Chapter Page
APPENDIX A: FACSIMILE OF THE QUESTIONNAIRE
APPENDIX B: FOOD DATA EDITING PROCEDURES
APPENDIX C: RECORD LAYOUT OF HIERARCHICAL FILE
AND EXPLANATION OF CALCULATED
VARIABLES
APPENDIX D: SAS CODE TO CREATE THE
RECTANGULAR ANALYSIS FILE
APPENDIX E: CODEBOOK OF THE RECTANGULAR
ANALYSIS FILE
APPENDIX F: DESCRIPTIVE STATISTICS FOR
SELECTED VARIABLES
APPENDIX G: DATA SET LOG
APPENDIX H: EXAMPLE OF SAS CODE TO PRODUCE
SELECTED TABLES FROM THE
ANALYSIS FILE
iv
TABLES
Table Page
IH.1 32FOOD GROUPS ......................................... 8
III2 EXAMPLE OF AME CALCULATION ........................... 9
V.1 PREVALENCE OF MISSING INCOME AMOUNTS
AND SOLUTIONS ADOPTED TO REPLACE THEM .............. 18
V.2 COEFFICIENTS, STANDARD ERRORS AND REGRESSION
DIAGNOSTICS OF THE EARNINGS IMPUTATION
EQUATION ............................................... 20
V.3 COEFFICIENTS, STANDARD ERRORS, AND REGRESSION
DIAGNOSTICS OF THE RETIREMENT INCOME
IMPUTATION EQUATION ................................... 21
V
FIGURES
Figure Page
II.1 NATIONAL ANALYSTSHIERARCHICAL FILE ................... 4
vii
I. INTRODUCTION
This report descn'bes the creation of the analysis file for the Alabama Food Stamp Cash-Out
Demonstration, conducted by Mathematica Policy Research (MPR) for the Food and Nutrition
Service (FNS) of the U.S. Department of Agriculture (USDA). The purpose, design, and findings
of the demonstration are discussed in Fraker et al. (1992).
As part of the demonstration, MPR conducted a survey of approximately 2,400 food stamp
recipient households in Alabama. The survey was administered during two separate visits to each
househoid's residence. The mainpurpose ofthe first visitwasto explain the objectives of the survey
and to ask the household to keep receipts of food purchases made in the following seven days. In
addition, a screener questionnaire wasadministered during the first visit,to collect some information
about the household's usual food expenditure, shopping patterns, and household composition. A
week later, the household was again visited by an interviewer, this time with the objective of
collecting information about the quantity and price paid for each food item used bythe household
during the preceding seven-day period. In addition, the main survey collected data on sources and
amounts of income, and a variety of other information pertaining to the use of coupon and check
food assistance benefits. A facsimile of the screener survey and of the main survey is presented in
Appendix A, while Fraker et al. contains a more detailed description of survey operations and
response rates.
The food data collected bythe surveywere processed byMPR's subcontractor, National Analysts,
with review and technical assistance from nutritionists from the USDA. National Analysts performed
data entry and coding of food-related data, and added information on the nutritive content of each
food item. This operation, conducted using a USDA nutrient conversion database, 1allowed each
fooditem on the fileto be augmented with the nutritive values for 30macronutrients, micronutrients,
1Hepburn (1982) provides a description of USDA's nutrient data bases.
1
and other food components. In addition, National Analysts imputed food prices that were not
reported by the respondents, and prices of food items that were not purchased--namely, food obtained
as gift or payment, home-grown food, and food obtained by redeeming WIC vouchers. For each
nutrient, National Analysts also computed household-level aggregates and the size of the household
in equivalent nutrition units (ENU). More details on the data processing conducted by National
Analysts are provided in Appendix B. The final outcome of the data processing conducted by
National Analysts is a hierarchical data file containing household-level, person-level, and food-item
level information. This file represents the starting point for the construction of the analysis file
described in this report.
The remainder of the report is organized as follows. Chapter II describes the hierarchical
structure of the National Analysts data file and the content of each record type. (Appendix C
contains the complete record layout for the National Analysts file.) Chapter III describes the SAS
program used to convert the National Analysts data file into a rectangular household-based analysis
file. (The actual source code of the SAS program is presented in Appendix D.) Chapter IV
describes the structure and content of the final SAS analysis file. (A complete codebook for the file
is in Appendix E.) Chapter V describes the procedures used to impute missing income amounts and
to substitute some of the reported amounts of income with amounts obtained from program records.
(Appendix F contains descriptive statistics for selected variables on the file.)
2
II. THE HIERARCHICAL DATA FILE CREATED BY NATIONAL ANALYSTS
The file created by National Analysts has six record types, which fall into three categories:
1. Household records,which contain information that pertains to the entire household.
There are four of these records for each household, and each of them contains
different types of data.
2. Person records,which contain data for each person in the household. There is one
record for each household member.
3. Food records, which contain data for each type of food used at home by the
household during the week prior to the interview. There is a record for each type
of food used.
Figure IL1 shows schematically the hierarchical organization of the National Analysts data file.
The data for a household begin with two consecutive household records. Record type 60 contains
all the household-level information collected in Section I of the questionnaire. Section I of the
questionnaire (see Appendix B) also collects information from each person in the households, but
this information is contained in the person records.
Record type 61 contains (1) allthe information collected in Section HI of the questionnaire, (2)
the information collected in the screener questionnaire about the shopping patterns of the household
and expenditure by type of store, and (3) some household-level recodes created byNational Analysts.
The recoded variables include measures of household size; type and number of meals eaten at home,
away from home, and as guests by members of the food consumption unit; number of meals eaten
by guests by the type of meal and the demographic characteristics of the guest; and the total money
value of food used by the food consumption unit.
Record type 61 is followed by one or more person records (type 65), starting with the record of
the sampled person, l Nineteen is the maximum number of person records for any household in the
1Exceptions to this pattern are discussed at the end of this section.
3
FIGURE I1.1
THE NATIONAL ANALYSTS HIERARCHICAL FILE
1
TYPE 60: Section I of the questionnaire
HOUSEHOLD RECORDS
TYPE 61- Section III of the questionnaire, screener data, recoded variables
J
I TYPE 65: first person in the household 1
PERSON RECORDS t
'_ I TYPE 65: last person in the household
J TYPE 70: first food item
FOOD RECORDS l
I TYPE 70: last food item
TYPE 75: size of FCU in ENU, nutritive values per ENUper day
I HOUSEHOLD RECORDS
TYPE 80: weekly aggregate nutritive values for FCU