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Restricted vs. Public Use Data

With very few exceptions, the public use data files are limited to data presented in aggregate form. Furthermore, all identifiers are removed from public use files. Some data are not useful for analysis without including direct or indirect personal identifiers. On the other hand; restricted use data files include more detailed geographic information, generally to the block level for the Decennial Census and census-tract level for surveys, as well as less restrictive top-coding. These files may be available to qualified researchers on approved projects with authorization to use specific data sets.

Census Demographic Data

Demographic Census and Surveys (Decennial Census, ACS, AHS, CPS, SIP)

The Central Plains Federal Statistical Research Data Center (CPRDC) is a joint project of the U.S. Bureau of the Census and the University of Nebraska-Lincoln, partnering also with the University of Nebraska Medical Center, University of South Dakota, University of Iowa, and Iowa State University to enable qualified researchers with approved projects to access unpublished Census data in order to conduct research that benefits Census Bureau programs.

Decennial Census (CEN)

Description: The Decennial Census Long Form Sample is a 1-in-6 sample of all households in the U.S. The questions asked of this sample include age, race, sex, educational attainment, income, place of work, occupation, household relationships, housing unit characteristics, etc. Because these files are large, processing with them can be very time and resource intensive. In cases where there is no valid response for an individual (or household where applicable), the item is filled in using a system of allocation. Allocation consists of using the response of a similar observation to fill in a missing item. A great deal of documentation of the Decennial Census is available on the Census Bureau’s website.



Survey Unit: Combination (household units)
Frequency: Every ten years
Time Periods: 1990 – 2000
Number of Observations: 16.6 million households and 43.5 million individuals most recently
Sponsor: Census Bureau
Data Webpage: http://www.census.gov/main/www/cen2000.html



American Community Survey (ACS)

Description: The American Community Survey (ACS) is a nationwide survey designed to provide communities a fresh look at how they are changing. The ACS collects information from U.S. households similar to what was collected on the Census 2000 long form, such as income, commute time to work, home value, veteran status, and other important data. As with the official U.S. census, information about individuals will remain confidential. The ACS will collect and produce population and housing information every year instead of every ten years. About three million households will be surveyed each year. Collecting data every year will reduce the cost of the official decennial census, and will provide more up-to-date information throughout the decade about trends in the U.S. population at the local community level. A similar program is planned for Puerto Rico. The ACS began in 1996 and has expanded each subsequent year.

Survey Unit: Housing Unit
Frequency: Annual
Time Periods: 1996 - 2011
Number of Observations: 3 million
Sponsor: Census Bureau
Data Webpage: http://www.census.gov/programs-surveys/acs/



American Housing Survey (AHS)

Description: The American Housing Survey (AHS) collects data on the Nation’s housing, including apartments, single-family homes, mobile homes, vacant housing units, household characteristics, income, housing and neighborhood quality, housing costs, equipment and fuels, size of housing unit, and recent movers. National data are collected in odd numbered years, and data for each of 47 selected Metropolitan Areas are collected about every four years, with an average of 12 Metropolitan Areas included each year. The AHS returns to the same housing units year after year to gather data; therefore, this survey is ideal for analyzing the flow of households through housing.

Survey Unit: Housing Unit
Frequency: Annual
Time Periods: 1984-1999, 2001-2005, 2007, 2009, 2011
Number of Observations: The American Housing Survey (AHS-MS) is conducted in 41 metropolitan areas on a rotating basis. Thirteen metropolitan areas are included, with a sample size of approximately 4,800 addresses in each AHS-MS area.
Sponsor: Department of Housing and Urban Development
Data Webpage: http://www.census.gov/programs-surveys/ahs/



Current Population Survey (CPS)

Description: The Current Population Survey - March Supplement (CPS) collects data concerning work experience, several sources of income, migration, household composition, health insurance coverage, and receipt of non-cash benefits.

Survey Unit: Household
Frequency: Annual
Time Periods: 1967-2011
Number of Observations: 72,000
Sponsor: Census Bureau and Bureau of Labor Statistics
Data Webpage: http://www.census.gov/programs-surveys/cps.html



National Crime Victimization Survey (NCVS)

Description: NCVS is the Nation’s primary source of information on criminal victimization. Each year, data are obtained from a nationally representative sample of about 40,000 households comprising nearly 75,000 persons on the frequency, characteristics and consequences of criminal victimization in the United States. Each household is interviewed twice during the year. The survey enables BJS to estimate the likelihood of victimization by rape, sexual assault, robbery, assault, theft, household burglary, and motor vehicle theft for the population as a whole as well as for segments of the population such as women, the elderly, members of various racial groups, city dwellers, or other groups. The NCVS provides the largest national forum for victims to describe the impact of crime and characteristics of violent offenders.

Survey Unit: Household
Frequency: Annual
Time Periods: 2008-2011
Number of Observations: 40,000 households comprising nearly 75,000 persons
Sponsor: Bureau of Justice Statistics
Data Webpage: http://www.bjs.gov/index.cfm?ty=dcdetail&iid=245



National Longitudinal Survey (NLS)

Description: The National Longitudinal Surveys (NLS), sponsored by the U.S. Bureau of Labor Statistics (BLS), are a set of surveys designed to gather information at multiple points in time on the labor market experiences of groups of men and women. Each of the cohorts has been selected to represent all people living in the United States at the initial interview date and born during a given period. This selection allows weighted conclusions to be drawn about the sample group that can be generalized to represent the experiences of the larger population of U.S. residents born during the same period. Sample design procedures ensure that the labor market experiences of blacks, Hispanics, youths, women, and the economically disadvantaged can be examined. The NLS program also includes surveys of the children born to women who participate in the National Longitudinal Survey of Youth 1979 (NLSY79). Detailed information is gathered biennially on the child’s home environment and cognitive, socioemotional, and physiological development; as they get older, these young adults report on their education, workforce participation, and fertility. This unique set of national surveys offers researchers the opportunity to study large panels of men, women, and children over significant segments of their lives. The primary purpose of the NLS is to collect data on the labor force experiences of adults and young adults. In addition, the surveys have regularly gathered information about a range of factors potentially affecting labor market attachment, including investments in education and training, geographic region of residence, the influence of parents, marital status and family responsibilities, socioeconomic status, work-related attitudes and aspirations, health problems, and job discrimination.

Survey Unit: Individual
Frequency: Annual
Time Periods: 1966-1999
Number of Observations: 5,000
Sponsor: Census Bureau and Bureau of Labor Statistics
Data Webpage: https://www.nlsinfo.org/investigator/pages/login.jsp



National Longitudinal Mortality Survey (NLMS)

Description: The National Longitudinal Mortality Study (NLMS) consists of a database developed for the purpose of studying the effects of demographic and socio-economic characteristics on differentials in U.S. mortality rates. The National Longitudinal Mortality Study (NLMS) is a unique research database based on a random sample of the non-institutionalized population of the United States. It consists of U.S. Census Bureau data from Current Population Surveys, Annual Social and Economic Supplements and a subset of the 1980 Census combined with death certificate information to identify mortality status and cause of death. The cohorts begin at various dates from 1973 through 1998 matched to death records dating through 1998. The survey includes demographic data, employment status, death records, and geographic information.

Survey Unit: Individual
Frequency: Variable
Time Periods: 1967-2011
Number of Observations: 3 million records total
Sponsors: Census Bureau, National Cancer Institute (NCI), National Center for Health Statistics (NCHS), National Heart, Lung, and Blood Institute (NHLBI), and National Institute on Aging (NIA)



Survey of Income and Program Participation (SIPP) Longitudinal

Description: The Survey of Income and Program Participation (SIPP) collects information on source and amount of income, labor force information, program participation and eligibility data, and general demographic characteristics to measure the effectiveness of existing federal, state, and local programs; to estimate future costs and coverage for government programs, such as food stamps; and to provide improved statistics on the distribution of income in the country. There are three basic elements contained in the overall design of the survey content. The control card is used to record basic social and demographic characteristics for each person in the household at the time of the initial interview. The second major element of the survey content is the core portion of the questionnaire. The core questions are repeated at each interview and cover labor force activity, the types and amounts of income received during the four- month reference period, and participation status in various programs. The third major element is the various supplements or topical modules that will be included during selected household visits. A list of topical modules includes work history, health characteristics (including disability), assets and liabilities, pension plan coverage, housing characteristics, child care, child support agreements, support for nonhousehold members, program participation history, reasons for not working, calendar year income and benefits, taxes, and education and training.

Survey Unit: Household
Frequency: Variable
Time Periods: 1984-1988, 1990-1993
Sponsor: Census Bureau
Data Webpage: http://www.census.gov/sipp/



Survey of Income and Program Participation (SIPP) Panels

Description: The Survey of Income and Program Participation (SIPP) collects information on source and amount of income, labor force information, program participation and eligibility data, and general demographic characteristics to measure the effectiveness of existing federal, state, and local programs; to estimate future costs and coverage for government programs, such as food stamps; and to provide improved statistics on the distribution of income in the country. There are three basic elements contained in the overall design of the survey content. The control card is used to record basic social and demographic characteristics for each person in the household at the time of the initial interview. The second major element of the survey content is the core portion of the questionnaire. The core questions are repeated at each interview and cover labor force activity, the types and amounts of income received during the four- month reference period, and participation status in various programs. The third major element is the various supplements or topical modules that will be included during selected household visits. A list of topical modules includes work history, health characteristics (including disability), assets and liabilities, pension plan coverage, housing characteristics, child care, child support agreements, support for nonhousehold members, program participation history, reasons for not working, calendar year income and benefits, taxes, and education and training.

Survey Unit: Household
Frequency: Monthly
Time Periods: 1984, 1990-1993, 1996, 2001, 2004, 2008
Number of Observations: 14,000 - 37,000
Sponsor: Census Bureau
Data Webpage: http://www.census.gov/sipp/

Economic Data

Demographic Census and Surveys (Decennial Census, ACS, AHS, CPS, SIP)

Economic data refer to the Economic Census of establishments and various surveys and data for establishments and firms. With very few exceptions, the public use versions for these files are limited to data presented in aggregate form. Click on the images below to access lists of establishment and firm based data, the survey period, the frequency of data collection, the years of data available at CES, a brief description, and the sponsoring federal agency. Access to these data will only be granted to qualified researchers on approved projects with authorization to use specific data sets.

Economic Data image

Linked Business and Household Data (LEHD)

Linked Business and Household Data (LEHD-ECF, LEHD-ICF, LEHD-QWI)

Longitudinal Employer-Household Dynamics (LEHD)

Overview: Longitudinal Employer–Household Dynamics (LEHD) data are the result of a partnership between the Census Bureau and U.S. states to provide high quality local labor market information and to improve the Census Bureau’s economic and demographic data programs. LEHD data are based on different administrative sources, primarily Unemployment Insurance (UI) earnings data and the Quarterly Census of Employment and Wages (QCEW), and censuses and surveys. Firm and worker information are combined to create job level quarterly earnings history data, data on where workers live and work, and data on firm characteristics, such as industry. Access to these data will only be granted to qualified researchers on approved projects with authorization to use specific data sets. All researcher access to restricted–use data occurs at one of the secure Census Research Data Centers (RDCs). The table below lists person, job and establishment based data available at the RDCs.

All LEHD data files except the Business Register Bridge are by state. A subset of states have data available at the RDCs. The list of states can be found on page 15 of LEHD Infrastructure Files in the Census RDC - Overview. This document provides detailed information about the LEHD data. In general, LEHD data are available from 2000 onwards. The availability of historical data prior to 2000 varies by state and data set. In the Years column of the table below, the start year is the year in which the state(s) with the earliest data has (have) data available for that data set. The latest year of data available at the RDCs is 2008. Some LEHD data contain Federal Tax Information (FTI). Use of LEHD data containing FTI requires approval by the Internal Revenue Service (IRS).

In addition to the restricted-use data available at the RDCs, LEHD creates public-use data sets and online tools. Quarterly Workforce Indicators (QWI) data and the online tools QWI Online and Industry Focus contain workforce statistics by demography, geography, and industry for each state. OnTheMap data and the OnTheMap web application have partially synthetic data on where workers live and work. These data and online tools have statistics for quarters up to about one year ago and include data for all states that have joined the LED Partnership.



Business Register Bridge (BRB)

Description: The LEHD employer-level data are at an establishment-level and can be linked to Census Bureau establishment and firm level micro data (e.g. Economic Censuses and Surveys) via this bridge. The bridge provides a crosswalk at various levels of business-unit aggregation.

Unit of Observation: Establishment

Years: 1990-2008



Employer Characteristics File (ECF)

Description: The Employer Characteristics File (ECF) consolidates most firm level information (size, location, industry, etc.) into two easily accessible files. The firm or SEIN level file contains one record for every YEAR QUARTER a firm is present in either the ES-202 or the UI, with more detailed information available for the establishments of multi-unit firms in the SEIN SEINUNIT file. The SEIN file is built up from the SEINUNIT file and contains no additional information, but should be viewed merely as an easier and/or more efficient way to access firm level data.

Unit of Observation: Establishment - Quarter

Years: 1989-2008



Employment History Files (EHF)

Description: The Employment History Files (EHF) are designed to store the complete in-state work history for each individual that appears in the UI wage records. The EHF for each state contains one record for each employee-employer combination–a job–in that state in each year. Both annual and quarterly earnings variables are available in the EHF.

Unit of Observation: Job (Person-Firm)

Years: 1985-2008



Employer Characteristics File (ECF)

Description: The Employer Characteristics File (ECF) consolidates most firm level information (size, location, industry, etc.) into two easily accessible files. The firm or SEIN level file contains one record for every YEAR QUARTER a firm is present in either the ES-202 or the UI, with more detailed information available for the establishments of multi-unit firms in the SEIN SEINUNIT file. The SEIN file is built up from the SEINUNIT file and contains no additional information, but should be viewed merely as an easier and/or more efficient way to access firm level data.

Unit of Observation: Establishment - Quarter

Years: 1989-2008



Geocoded Address List (GAL)

Description: The Geocoded Address List (GAL) is a data set containing unique commercial and residential addresses in a state geocoded to the Census Block and latitude/longitude coordinates.

Unit of Observation: Establishment

Years: 1990-2008



Individual Characteristics File (ICF)

Description: The Individual Characteristics File (ICF) for each state contains one record for every person who is ever employed in that state over the time period spanned by the state’s unemployment insurance records.

Unit of Observation: Person

Years: 1985-2008



Quarterly Workforce Indicators (QWI)

Description: The QWI are a set of economic indicators – including employment, job creation, wages, and worker turnover that can be queried by different levels of geography (state, county, metro, and workforce investment area) as well as by detailed industry, gender, and age of workers.

Unit of Observation: Establishment - Quarter

Years: 1990-2008



Unit-to-Worker (U2W)

Description: The Unit-to-Worker (U2W) file contains ten imputed establishments for each worker of a multi-unit employer.

Unit of Observation: Job (Person-Establishment)

Years: 1990-2008

Public Health Data

Public Health Data (NHIS, NHANES, MEPS-IC, NSFG)
Public Health Data from Partnering Agencies
NCHS and AHRQ

Data Webpage: http://www.cdc.gov/rdc/B1dataType/dt1222.htm



National Health Care Surveys

National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care
Survey (NHAMCS)

National Hospital Discharge Survey (NHDS)
National Nursing Home Survey (NNHS) and National Nursing Assistant Survey (NNAS)
National Home and Hospice Care Survey (NHHCS) and National Home Health Aide Survey (NHHAS)
National Survey of Residential Care Facilities (NSRCF)
National Study of Long-Term Care Providers (NSLTCP)



National Health Interview Survey (NHIS)



National Survey of Family Growth (NSFG)



State and Local Area Integrated Telephone Survey (SLAITS)

National Survey of Children’s Health (NSCH)
National Survey of Children with Special Health Care Needs (CSHCN)



NCHS Data Linkage Activities

Linked Mortality Data Products
Linked Medicare Enrollment and Claims Files Data
Linked Medicaid Enrollment and Claims Data
Linked Social Security Benefit History Data



National Vital Statistics System (NVSS) Data Release and Access Policy

National Maternal and Infant Health Survey



Agency for Healthcare Research and Quality (AHRQ) - Restricted Use

Household Component-Insurance Component Linked File
Nursing Home Component
Medical Provider Component
Area Resource File
Two-Year, Two-Panel File
Data Webpage: http://www.ahrq.gov/
Restricted Use: http://meps.ahrq.gov/mepsweb/data_stats/onsite_datacenter.jsp