dresses that do not indicate street name and house number. Consequently, when the Census Bureau receives an updated DSF that has more addresses than are currently listed on the MAF for a rural area, it is not easy to determine which addresses are new. (Research is under way to determine if there are effective ways to use the DSF for address updates in rural areas.)
The identification of CAUS counties for listing is based on an algorithm that considers the address characteristics of existing MAF records for the county, changes in postcensal housing unit estimates for the county, and changes in the DSF tallies for the county. A second stage takes the counties identified for some potential CAUS listings and identifies blocks that would be expected to yield the most new units. Two ACS sources are used to identify CAUS-eligible blocks. One is blocks with addresses in which ACS fieldwork returned numerous outcomes such as “unable to locate” or “address nonexistent.” The other is blocks with a high percentage of addresses that were unmailable from the ACS mailout operation because they lacked a house number/street name/ZIP code address. A third source is from field representatives who identify blocks needing updating while they are in the field completing other block listing assignments. The number of selected blocks from those ranked highly by the algorithm is dictated by budget and operational constraints.
Dean and Peterson (2005) conducted the first evaluation of CAUS. They examined the CAUS listings completed between September 2003 and August 2004 to evaluate the targeting of blocks for CAUS work, review the quality of the CAUS listings, and find out if other Census Bureau operations would have captured the address updates or if CAUS was the only means to collect the information. The study found that CAUS was successful in adding addresses to the MAF that would not have been added by other means, but the study was limited in scope and did not address the issue of addresses that are missed because of constraints on the CAUS operation. No further evaluation has been conducted of CAUS.
Recommendation 4-1: Given the centrality of the MAF to the ACS, the Census Bureau should ensure that adequate resources are provided to attain the highest possible completeness and accuracy of MAF address information on a continuous basis.
Recommendation 4-2: The Census Bureau should plan now for programs to follow the 2010 census to ensure that the MAF is updated on a continuous basis more completely than is being done prior to 2010. These programs should include not only the current updates from the DSF and the CAUS but also such initiatives as continuing local review,