2000115-Strengthening-Communities-with-Neighborhood-Data

Progress in Data and Technology 83
than those obtained with the higher sampling rate used in the Decennial
Census long form. For the first ACS release of census tract–level data
based on surveys collected from 2005 to 2009, the sampled households
represented only 11 percent of all households, compared with about
17 percent in the 2000 Decennial Census (Hefter 2010). This difference
resulted in coefficients of variation for ACS estimates that were roughly
1.5 to 2 times larger than their census sample counterparts (Beaghen
et al. 2012). Starting in 2011, the Census Bureau increased the annual target
sample from 3 million addresses to 3.54 million, which will improve the
sample coverage somewhat over time.
The Census Bureau now prominently publishes the upper and lower
limits alongside the estimate value. Even so, the estimates are generally
presented in news articles or community analysis without regard to margin
of errors. For analysis purposes, the larger margins of error make it
more difficult to confidently differentiate among conditions in different
geographies in a given year, or across years for a given geography. More
troubling is that the reliability of the estimates is not constant across different
types of neighborhoods. The coefficients of variation are higher
for census tracts that have lower median household income and greater
shares of nonwhite population, creating particular challenges for the
study of vulnerable neighborhoods (Spielman et al. 2014).
Recognizing the difficulty users would have transitioning to the ACS,
the Census Bureau produced the Compass products, a set of educational
materials produced by Bureau staff and contractors. These materials
include several handbooks for different audiences (e.g., researchers,
journalists), presentations on a variety of topics, and an e-tutorial (US
Census Bureau n.d.). In addition, the Census Bureau funded the Population
Reference Bureau in early 2013 to launch an ACS user’s group,
which will provide training at academic conferences and establish an
online community platform where users can exchange questions and
resources. In addition, several Census Information Centers and NNIP
partners have developed training for their nontechnical audiences on
using and understanding the ACS.
State and Local Government Data
Chapter 2 provides an introduction to administrative data generated
by state and local government operations and record keeping, as well
as the increased internal use of the systems to improve efficiency and