follow-up (see Section 3-B.3). This plan meant that some people in the P-sample who moved to their present residence after Census Day might be falsely coded as not matching to a census enumeration. This could happen if they did not mail back a questionnaire and their Census Day address was not included in the sample for nonresponse follow-up. The decision not to use PES-B was carried over to the A.C.E.
The 2000 A.C.E. had two objectives: (1) to find out who lived at each P-sample address on Census Day and determine whether they were enumerated or missed in the census at that address and (2) to find out who lived at each P-sample address as of the A.C.E. interview day. This procedure is called PES-C; it results in obtaining information not only for nonmovers and inmovers (interview day residents not resident on Census Day), but also for outmovers (Census Day residents not resident on interview day).
The PES-C procedure involved estimating the P-sample match rate for movers by matching outmovers. At the same time, for most poststrata, the A.C.E. estimated the number of matched movers by applying the outmover match rate to inmovers. The underlying assumption is that inmovers would be more completely reported than outmovers. The advantage of PES-C is that a searching operation for the Census Day residence of inmovers is not required. The drawback is that the quality of the information collected to use in the matching for outmovers may be impaired because their information is always supplied by other people. The decision to use the PES-C procedure added complexity to the A.C.E. estimation. Tests of Integrated Coverage Measurement in 1995 and 1996 used PES-A, in which the goal is to find out who lived at each P-sample residence on Census Day and determine whether they were enumerated or missed in the census. PES-C is similar to PES-A except that PES-C applies the match rate for outmovers to the number of inmovers, instead of using both the match rate and number of outmovers in the DSE estimation (see Liu et al., 2001:1).
Another important change from the 1990 PES concerned the targeted extended search procedure for searching surrounding blocks if a search in the sampled block cluster did not turn up a match for a