The A.C.E. survey in 2010 must be large enough to provide estimates of coverage errors that provide the level of precision targeted for the original (March 2001) A.C.E. estimates for population groups and geographic areas. Areas for improvement that should be pursued include:
the estimation of components of gross census error (including types of erroneous enumerations and omissions), as well as net error;
the identification of duplicate enumerations in the E-sample and nonresidents in the P-sample by the use of new matching technology;
the inclusion of group quarters residents in the A.C.E. universe;
improved questionnaire content and interviewing procedures about place of residence;
methods to understand and evaluate the effects of census records that are excluded from the A.C.E. matching (IIs);
a simpler procedure for treating people who moved between Census Day and the A.C.E. interview;
the development of poststrata for estimation of net coverage errors, by using census results and statistical modeling as appropriate; and
the investigation of possible correlation bias adjustments for additional population groups.
Recommendation 6.2: The Census Bureau should strengthen its program to improve demographic analysis estimates, in concert with other statistical agencies that use and provide data inputs to the postcensal population estimates. Work should focus especially on improving estimates of net immigration. Attention should also be paid to quantifying and reporting measures of uncertainty for the demographic estimates.
Recommendation 6.3: Congress should consider moving the deadline to provide block-level census data for legislative redistricting to allow more time for evaluation of the completeness of popula-