README.md

In davidthaler/PUMSutils: Computes Point Estimates and Standard Errors on the ACS PUMS Data

PUMSutils

ACS PUMS Data

The American Community Survey (ACS) is an annual survey conducted by the U.S. Census Bureau, covering many of the same topics as the decennial census. It is a 1% sample, and it comes in 2 parts: a housing survey of household units and a population survey of people. ACS data is available in several forms. Online, you can get tabulated results from American FactFinder, or look at censusreporter.org for a friendlier web interface. Microdata is available through the Public Use Microdata Sample, or PUMS. This contains actual responses to the ACS, one per row. This allows essentially any query to be formed, not just those provided by AFF. However, the data is harder to work with, since every query requires doing tabulation.

The most important thing to know about the ACS PUMS data is that it is a weighted sample. Each row has an expansion weight indicating the number of households or people represented by this row. This complicates estimation, especially of standard errors. The PUMSutils package reduces the required computation to function calls. It has functions for computing estimates and standard errors for counts, proportions, and means, as well as computing tables and point estimates for medians and quantiles. It also contains utility functions for loading PUMS datasets, renaming the numerous integer-coded categorical variables in the PUMS data, and other common operations on this dataset.

Usage

The PUMSutils package includes a sample data set called wa.house16. Its documentation is available in R with ?wa.house16. We compute some example statistics about Washington State housing using this data and the functions in PUMSutils below.

Estimate count, standard error and 90% margin-of-error for the total number of housing units in Washington State

line.estimate(wa.house16, estimate)

Compute counts, standard errors and 90% margin-of-error for rented, owned and vacant housing in Washington State, renaming the integer coded categorical variable TEN:

wa.house16$Own.Rent <- acs.translate(wa.house16, 'TEN', c(1:4, NA), c('own', 'own', 'rent', 'rent', 'vacant'))    
group.count(wa.house16, 'Own.Rent')

In the PUMS data, the variable TEN denotes housing tenure. It is an integer-coded categorical variable. It has the levels: 1 = Owned with mortgage, 2 = Owned free and clear, 3 = Rented for cash, 4 = Occupied without rent, NA = Vacant. This description can be found at the technical documentation page for the ACS. The technical documentation page also has ground-truth values for these calculations. A portion of that data, for the 2016 ACS housing data for Washington, is included in this package as wa.gold16. The example above corresponds to rows 1, 3, 4, and 9 in wa.gold16.

The ACS data includes hundreds of variables, each with its own definition. This package includes the data dictionary for the 2016 1-year ACS data in the variable data.dict16 and a function for querying it for information.

acs.describe(data.dict16, 'TEN')

Integer-coded categorical fields, common in the ACS data, can be automatically rewritten to have text labels in place of the integers using acs.recode.

wa.pop16$employment <- acs.recode(wa.pop16, 'ESR', data.dict16, 40)
group.count(wa.pop16, 'employment')

The ACS PUMS data is a weighted sample and that complicates plotting. PUMSutils includes functions for making quick plots using the sample weights. See the vignette for more on plotting.

vignette("PlottingPUMS")

For other functions, see the package docs.

Installation

This package can be installed from github using devtools:

devtools::install_github('davidthaler/PUMSutils')

References

See the PUMS data dictionary for field definitions.

The ACS PUMS technical documentation page has more information about using the expansion weights.

Contributing

Feel free to raise an issue if you find a bug, or have a feature request. Pull requests are also welcome if you fix a bug or have new functionality that you think should be included.

davidthaler/PUMSutils documentation built on July 13, 2019, 9:58 a.m.