Participants & Presenters
Participant List
New Questions and Modifications in the ACS (2009)
Information for each of the new questions that were added to the 2009 ACS: health insurance coverage, Bachelor's field of degree, disability, marital history, and other new tables. Additionally, modifications were performed on food stamps tables and other tables.
http://www.census.gov/acs/www/data_documentation/2009_product_changes/
Question by Question Fact Sheets
The fact sheets have ACS question(s), how long the question has been in use, a description of how the federal government uses the data and how those uses translate into community benefits.
http://www.census.gov/acs/www/about_the_survey/questions_and_why_we_ask/
ACS Questionnaires
On this page are examples of the current materials mailed to the sample addresses in the housing unit (HU) sample, and examples of the current materials used in the group quarters (GQ) interviewing. Also included are the HU and GQ questionnaires from prior years, and summary documents showing the changes in the questionnaires from year to year.
http://www.census.gov/acs/www/SBasics/SQuest/SQuest1.htm
Technical Appendix
Technical Appendix from the ACS Compass Products
Data Collection & Processing
http://www.census.gov/acs/www/Downloads/survey_methodology/acs_design_methodology_ch13.pdf
Chapter 13 of the ACS Design and Methodology Report discusses how aggregated data products and PUMS are prepared. For more help, see the entire report, or other individual chapters, at this link:
http://www.census.gov/acs/www/methodology/methodology_main/
Group Quarters Definitions
http://www.census.gov/acs/www/data_documentation/documentation_main/
What the ACS can tell us about Mixed Mode Surveys
http://www.psc.isr.umich.edu/dis/workshop/references/ISRMixedMode.pdf
This is a presentation given by Deborah Griffin, Census Bureau, at a joint SRC/PSC brownbag. It has a great deal of information on the details of the different modes of data collection (mail, phone, in-person); differences in response across the country; mode effects, etc.
Sample size information for years prior to 2007 will remain on the ACS website and will not be added to AFF.
Accuracy of the Data
http://www.census.gov/acs/www/UseData/Accuracy/Accuracy1.htm
These documents provide data users with a basic understanding of the sample design, estimation methodology, and accuracy of the data.
Also note that there is a direct link to the Design and Methodology report (http://www.census.gov/acs/www/Downloads/survey_methodology/acs_design_methodology.pdf)
Quality of the Data
http://www.census.gov/acs/www/methodology/sample_size_and_data_quality/
These quality measures are produced annually to accompany each ACS data release and describe the quality of those data. The quality measures are available at national and state levels. Clicking on "definitions" will provide additional information on each of these measures, including why the measure is important and how it was calculated.
Guidance on Comparing ACS data to Other Sources
http://www.census.gov/acs/www/guidance_for_data_users/comparing_data/
The Census Bureau encourages users to compare ACS data with data from other sources. Guidance is needed before drawing conclusions because in some instances comparisons could be misleading due to differences in questions or methods. This page provides three forms of guidance - general guidance, item-specific guidance, and examples. For all comparisons of differing time periods, users should take into consideration that geographic boundaries for the area of interest may have changed
"College town 'poverty' exposed: Low-income students help win grant money"
Stephen Koff and Bill Sloat | Cleveland Plain Dealer
September 17, 2006
Data from the Summary File Exercises
Poverty rates for places [Excel]
Vacancy data for Cleveland census tracts (Census 2000) [Excel]
Median Income for zip codes (Census 2000) [Excel]
Additional PDQ-Explore Examples
Using data from Census 2000
Using ACS and Census data
Looking at change over time
Additional Resources for PDQ-Explore
Indexing for Cost of Living
Variable Names across the Census, CPS, and IPUMS
Guide to Variables
Selected variables from IPUMS with PUMS, ACS, and CPS equivalent names
Register to use IPUMS
(required for making an extract)
Instructions for using the IPUMS Data Extraction System
Instructions for opening data on PC
Making an Extract of the ACS 3-year data from IPUMS
[ppt] [pdf]
Extract
(zipped)
Extract
(not zipped)
SAS program Stata program SPSS program
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.
Guide to Variables
Selected variables from IPUMS with PUMS, ACS, and CPS equivalent names
Register to use IPUMS
(required for making an extract)
Instructions for using the IPUMS Data Extraction System
Instructions for opening data on PC
Making an Extract of the ACS 3-year data from IPUMS
[presentation]
Extract
(zipped)
Extract
(not zipped)
SAS program
Social Explorer
This site provides easy access to interactive maps based on census data. One is limited to the items they make available, particularly if you use the "free" version. Many universities have subscriptions to the full service.
CensusScope
CensusScope provides access to charts & trends, maps, rankings, and segregation scores based on Census 2000 data (and soon to be Census 2010 and ACS products). For the most part, the maps are at the state or county level, not lower levels of geography like census tracts.
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.