DOI: 10.6077/stjy-3357
title: American Community Survey, 2008: 1-year Public Use Microdata Sample

description: &lt;p&gt;The American Community Survey (ACS) is a part of the Decennial Census Program, and is designed to produce critical information about the characteristics of local communities. The ACS publishes social, housing, and economic characteristics for demographic groups covering a broad spectrum of geographic areas in the United States and Puerto Rico. The Public Use Microdata Sample files, or PUMS, are a sample of the actual responses to the American Community Survey and include most population and housing characteristics. The PUMS will allow users to tabulate data to their own specifications. The 2008 ACS 1-Year PUMS currently contains data for the nation, states, Puerto Rico, and Public Use Micro Data Sample Areas (PUMAs). PUMAs are special nonoverlapping areas that partition a state, and each PUMA contains a population of about 100,000. State governments drew the PUMA boundaries at the time of the 2000 Census.&lt;/p&gt;
description: American Community Survey: Public Use Microdata Sample
description: collection_notes: The 2008 PUMS was designed to sample one percent of the housing units and one percent of the GQ persons in the United States, District of Columbia, and Puerto Rico. The PUMS sample sizes were based on the Population Estimates Program estimates for housing units and GQ persons.

Tables 1 and 2 show PUMS sample sizes next to the corresponding ACS estimates by state, D.C. and P.R. Table 1 shows housing units and Table 2 shows GQ persons. (See pums_accuracy_2008.pdf for tables)

The PUMS sample was selected for HUs and GQ persons separately. The PUMS sample of persons in households was selected by keeping all persons in PUMS HUs. The systematic sampling method used sampling intervals chosen to yield the sample sizes given in Tables 1 and 2. The sampling interval for each state and HU/GQ sample is the ratio of the number of records available for sampling and the required sample size (sampling intervals are not rounded to integers).

The sampling for HUs was performed on ACS sample of HUs as follows:

1. Records of HUs were sorted by: PUMA, ACS weighting area, interview mode, type of vacant, tenure, building type, household type, householder demographics (race, Hispanic origin, sex and age), county, tract, and housing unit weight.
2. Systematic sampling was applied as described below:
 a. Within each state, a random number is chosen between zero and the sampling interval. A counter is initialized with the random number.
 b. At each record, the value of the counter is incremented by one and compared to the sampling interval.
 i. If the counter’s new value is greater than the sampling interval, the record is selected for the PUMS. The counter is decreased by the sampling interval with the new value passed to the next record.
 ii. If the counter is less than the sampling interval, the record is not selected for the PUMS and the value of the counter is passed to the next record without altering its value.
3. All HUs selected for PUMS were placed in the PUMS HU sample file.
4. The PUMS HU sample file was matched to the ACS sample of persons. All persons in
selected HUs were placed in the PUMS person sample.

The sampling for GQs was performed on the ACS sample of GQ persons as follows:
1. GQ persons were sorted by size of GQ (large vs. small), type of GQ, PUMA, demographics (race, Hispanic origin, sex and age), county, tract, and GQ person weight.
2. Systematic sampling was applied as described above under HUs.
3. All selected GQ persons were added to the PUMS person sample. A placeholder record was also placed in the PUMS HU file for each PUMS GQ person.

Collection mode varied, CATI and CAPI phases followed mailings.