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Survey of Program Dynamics


Type of File:

Microdata; units of observation are individuals, families, and households.
Universe Description: The universe is the resident population of the United States, excluding persons living in institutions and military barracks.
Introduction: The file is intended to be used as a research file. This is a calendar year file for 1996 and is intended and allows for longitudinal analyses through the ability to match to the Survey of Income and Program Participation (SIPP) 1992 and 1993 Panel Longitudinal files using the following match keys: SIPP panel number, sample unit identification number, person number and entry address ID (SIPP-PNL, PP-ID, PP-PNUM and PP-ENTRY). The data were collected using a modified Current Population Survey March questionnaire.

The Survey of Program Dynamics (SPD) interviewed about 30,125 households from retired 1992 and 1993 SIPP panels, which were scientifically selected on the basis of area of residence to represent the nation as a whole.

The SPD provides estimates of the economic status and activities of the population of the United States. The SPD is designed to provide a large amount of detailed and supplementary data. Such data are made available to meet a wide variety of needs.

Information is available from the survey not only for persons currently in the labor force but also for those who are outside the labor force. The characteristics of such persons - whether married women with or without young children, disabled persons, students, older retired workers, etc., can be determined. Information on their current desire for work, their past work experience, and their intentions for job seeking are also available.

The SPD contains basic demographic and labor force data, plus additional data on work experience, income, and noncash benefits.

Subject-Matter Description: The file contains basic demographic, social, and economic characteristics data for calendar year 1996 for each member of the households selected from the 1992 and 1993 SIPP Panels. These include age, sex, race (White; Black; American Indian, Eskimo, and Aleut; Asian or Pacific Islander; and Other), ethnic origin (23 categories including 7 Hispanic origin categories), marital status, household relationship, education, and veteran status. Limited data are provided on housing unit characteristics such as units in structure and tenure.

This file, also known as the SPD Research File, provides monthly labor force data, but in addition, provides supplemental data on work experience, income and noncash benefits. Comprehensive work experience information is given on the employment status, occupation, and industry of persons 15 years old and over. Additional data for persons 15 years old and older are available concerning weeks worked and hours per week worked, reason not working full time, total income and income components. Data on employment and income refer to the preceding year, although demographic data refer to the time of the survey.

This file also contains data covering nine noncash income sources: food stamps, school lunch program, employer-provided group health insurance plan, employer-provided pension plan, personal health insurance, Medicaid, Medicare, CHAMPUS or military health care, and energy assistance.

Geographic Coverage: United States. Codes are included for 41 individual States, although the sample was not designed to produce State estimates. Areas in the SPD sample in nine other States are identified in three groups for confidentiality reasons. Technical Description:

This is a Current Population Survey (CPS) hierarchical file structure, not a standard rectangular flat file.

    File Structure: Hierarchical
    File Size: 148,521 Records

    Record    Logical    Record
    Type       Records   Size
Household   37,830      868 Characters
Family        33,061      868 Characters
Person        77,630      868 Characters

Total         148,521     868 Characters

File Sort Sequence of Sample Units: FIPS state code (GESTFIPS) in its suppressed form.

Reference Materials

Survey of Program Dynamics (SPD) 1997 Technical Documentation. The documentation includes this abstract, the data dictionary, an index to the data dictionary, relevant code lists, questionnaire facsimiles, and general information on SPD.

Survey of Income and Program Participation Users' Guide. The Users' Guide contains a general overview of the file as well as chapters on survey design and content, structure and use of cross-sectional files, linking waves and reliability of the data. A single copy accompanies each technical documentation or tape order. Additional copies are available from Customer Services, Administrative and Customer Services Division, Bureau of the Census, Washington, DC 20233.

Survey of Income and Program Participation Quality Profile. The Quality Profile summarizes the SIPP sample design, sample selection, and data collection procedures. More importantly, the report also summarizes, in convenient form, what is known about the sources and magnitude of errors in estimates from SIPP. Without such summaries, users wanting information about the quality of SIPP estimates would need to search through a large body of literature, some of it not easily accessible. The report covers both sampling and nonsampling error; however, the primary emphasis is on the latter. Copies of this report are available from Customer Services, Administrative and Customer Services Division, Bureau of the Census, Washington, DC 20233.

Related Printed Reports Related printed reports include working papers, compilations of papers presented at annual meetings of the American Statistical Association, articles appearing in the Journal of Economic and Social Measurement, and reports in the P-70 series of the Current Population Reports. See the Users' Guide that accompanies the documentation for ordering information. Some of these reports are also available at the Bureau of the Census homepage on the Internet at http://www.census.gov.
Related Electronic Data Files SIPP 1992 and 1993 Longitudinal files are available from Customer Services, Administrative and Customer Services Division, Bureau of the Census, Washington, D.C. 20233. Extract files may also be downloaded from the SIPP Website under Data Access using either the FERRET or DES extraction systems.
File Availability Files are available on computer tape at 6250 bpi, ASCII or EBCDIC, and standard ANSI labeling. Files are also available on CD-R(compact disc-readable) in ASCII, call 301-763-4100 for price information. Information on some SIPP files may also be accessed on the INTERNET at gov/ftp/pub/mp/www/tape/mstap17c.html. The file may also be made available on IBM 3480 compatible tape cartridge. A machine-readable dictionary is contained at the end of each file. This dictionary is also available separately on one tape reel or cartridge.

Additional information on particular subjects can be obtained by contacting an office listed below.








Contact Phone Number




Demographic Statistical Methods Divison


Survey of Income and Program Participation








Fertility and Family Statistics




Labor Force


Housing and Household Economic Statistics


Labor Force and Transfer Statistics




Income Sources


Housing and Household Economic Statistics


Income Statistics




Program Eligibility


Housing and Household Economic Statistics


Labor Force and Transfer Statistics




Health Care and Insurance


Housing and Household Economic Statistics


Poverty and Health Statistics




The SPD Bridge file was processed using programs for the March Current Population Survey Demographic Supplement. These data have undergone limited editing and review and should be used carefully.

Interim Calendar Year Files

So that the research community can assess the quality of the SPD sample and make some preliminary assessment of the immediate impact of welfare reform, we are issuing this interim file from the 1997 bridge survey. The interim file is identical to the March CPS in format. It repeats the March CPS content and includes additional information from the SPD. This additional information includes panel weights corresponding to the cohort and the following match keys needed to merge SPD and earlier SIPP data:

SIPP Panel Number SIPP_PNL

Sample Unit Identification Number PP_ID

Entry Address ID PP_ENTRY

Person Number PP_PNUM

A note of caution about this interim file. It will appear to be a cross-section snapshot of the population, like the March CPS. It is important to emphasize that it is not because there has been differential nonresponse over the life of the SIPP and SPD Bridge surveys. Weighting compensates for some of the bias, but may not totally eliminate its effect on estimates. It is simply one segment in the array of longitudinal data being produced for SPD. The weights are longitudinal and only valid to estimate 1996 characteristics of the 1992/1993 SIPP cohorts. Children born since the beginning of the SIPP panel do not receive longitudinal weights in this first file so the distribution of population by age will be skewed toward the older population. However, users can construct an approximate weight for these children by assigning the weights of the mother to each child.

Relationship variables

There are several relationship variables on the person record. Only the A_EXPRRP variable has been reviewed and edited. A_EXPRRP is the "edited relationship to reference person." We recommend using A_EXPRRP in your analysis and not using, or using with caution, the following relationship variables:A_FAMREL, A_PFREL, HHDREL, FAMREL, and HHDFMX. These variables will be edited for the forthcoming SPD longitudinal file.

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SPD Data Access

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Contact: (dsd.survey.program.dynamics@census.gov)
URL: http://www.sipp.census.gov/spd/


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