Target audience for this post: survey methodologists
On Nov 19, I attended an ACS Data Users Group webinar hosted by the Population Reference
Bureau and Sabre Systems. The topic was the Planning Database (PDB), which is a database
at the tract and block group level, focusing on low response. The main objective is to
figure out where the Census will have lower response with the 2020 Census and plan to
implement different techniques to improve response rates in those areas.
The speakers were Nancy Bates and Travis Pape.
The PDB includes the geography (tract and block group), demographic characteristics, and
then, Census operations data, e.g. mail-back, bilingual rates, the 2010 Census Mail return
rate AND the LOW RESPONSE SCORE, based on a model using 5-years of ACS data. The model
includes 25 variables, of which the top 3 variables were: rent (vs own); age ( 18-24),
and female head of household with no husband present. Other variables include household
size, presence and age of children, poverty, education, race and Hispanic origin.
The regression results are R2 of .56 at the block group level, and R2 of .55 at the tract
level. These results are for mail-back returns, and the Census Bureau is planning on
over 60% returns for the 2020 Census using Internet, so the results may be different after
newer ACS results which included Internet response method are incorporated into the
Currently, the 2014 PDB which includes 2008-2012 ACS estimates and 2010 Census operations
data is available, and an updated PDB based on more recent ACS will be available
approximately in March 2015. The files are only available as nationwide files, zipped
CSV format, one file for tracts and one file for block groups. The tract level file is 86
Mb. The Block Group file is 152 Mb.
Bottom line - the model variables seem consistent with the results of non-response to
household travel surveys, so I am thinking that when a large household travel survey is
being planned, these data could also be useful for targeting different approaches to
improve response rates, or oversampling housing unit addresses in low responding areas.
Hope I didn't make any grievous errors in my summary above! If I did, I hope that
someone from the Census Bureau will post corrections.
FHWA Office of Planning
206-220-4460 (in Seattle)