Poverty Workshop, Summer 2009

Thursday, June 25, 2009

Technical - Statistical

Statistical Links

Technical Issues (mostly statistical) Associated with the ACS
[PowerPoint presentation]

Appendices associated with each ACS Compass product

SAS code for using Replicate Weights
Statistical packages such as stata can handle replicate weights to produce standard errors and tests of significance. However, for the ACS and CPS, the replicate weights are based on a successive difference model rather than a jack-knife or generalized linear model. No statistical package handles successive difference models as an option.

Thus, one has to go through the actual algorithm to produce standard errors based on the successive difference replicate weights. The following program provides the code for this:

SAS code for using replicate weights

Replicate Weights
Garrett, B. Dale and Michael Starsinic. 2008. "ACS Public Use Microdata Samples of 2005 and 2006 - How to Use Replicate Weights." Presentation at AAPOR Conference, New Orleans, May 16, 2008.

Theoretical basis for successive difference model is:
Fay, R. and Train, G. 1995 "Aspects of Survey and Model-Based Postcensal Estimation of Income and Poverty Characteristics for States and Counties," Proceedings of the Section on Government Statistics, American Statistical Association, pp. 154-159.

Technical - Census Geography

Geography Extras

Creating County level statistics from microdata files

The following document illustrates how one can use microdata files to produce statistics at the county level.

One uses a PUMA equivalency crosswalk to determine which PUMAs to combine for a county and/or which PUMA to associate with multiple counties.

The example uses Illinois as an example, illustrating the percent boomers by PUMA and the percent boomers by county.

Creating County Level Statistics from Microdata Files

Contact me for the programming behind this. The goal is to create a widget that will take PUMA-based statistics as input and output county-based statistics as input. However, all that exists at the moment is a SAS-based program.

PUMA Equivalency File [based on 2000 Census]

The following PUMA equivalency file describes how each PUMA corresponds to counties in the US. The ACS uses the same mapping scheme.

PUMA Equivalency File [Excel]

PUMA Equivalency File [Text]

Tuesday, June 23, 2009

GIS/Thematic Maps

Shape Files

PUMA shapefiles (United States), [zip]

Census tract shapefile (Louisiana), [dbf]

Census tract shapefile (Louisiana), [shp]

Census tract shapefile (Lousisana), [shx]

Posted by lisan at 09:20 AM | Comments (0)

Mapping Resources

Introduction to Mapping [ppt]
Jeff Strickland

ACS Map Making Tutorial
Jennifer Ailshire

GETTING CENSUS DATA for CENSUS 2000: With Emphasis on Mapping Themes from Census 2000
This is a tutorial from the University of Virginia on how to get data into ArcGIS. This is one of the more frustrating steps in making maps. Pay special attention to the bottom of page 2 and top of page 3.

Using ArcGIS
This is a good generic guide to using ArcGIS. It has some specific links to the Yale University library, which developed the resource. Ignore these and use it as a general reference.

Data file for class exercise
Child Poverty [PUMA-based]

Short Guide to Statistical/GIS Resources
Jeff Strickland

Mapping from the Census Bureau website
This is a short description of how to make maps using the Census Bureau website. It requires no GIS skills or software. All of the tools reside on the Census Bureau site. The drawback is the limited flexibility on being able to find a table and/or geography that meets the users' needs.

Sunday, June 21, 2009

Using PDQ Explore

PDQ Explore software

The following is a link to the PDQ-Explore software that you used during the workshop. You will need to download the zip file to the C:\ drive on your PC.
PDQ-Explore

As a reminder of what you need to do to get started, here is the introduction to Using PDQ-Explore, which includes some technical notes.
Introduction to PDQ-Explore

Guides to PDQ Explore
There are about 10 guides that describe in quite a bit of detail how to do many of the procedures covered in the class. If you find you need a reminder, check these out. You will need to scroll down the page to see the guides.