percent for short-form and long-form mail returns and 11.7 percent and 11.3 percent for short-form and long-form enumerator-filled returns.
In an analysis of the 1990 PES for 1,392 poststrata, Ericksen et al. (1991:Table 1) found that both the gross omission rate and the gross erroneous enumeration rate were inversely related to the “mailback rate” (equivalent to the mail response rate) for PES cases grouped by mailback rate category.1 The relationship was stronger for omissions than for erroneous enumerations—the omission rate was 3 percent in the highest mailback rate category and 19 percent in the lowest mailback rate category, compared with 4 percent and 10 percent, respectively, for the erroneous enumeration rate. Consequently, the net undercount rate also varied inversely with the mailback rate.
Using data from the original Accuracy and Coverage Evaluation (A.C.E.) P-sample and E-sample, we carried out several analyses of the relationship between mail returns and population coverage for 2000. The analyses are not as comparable as we would have liked to the 1990 analyses summarized above: not only are there differences between the PES and the A.C.E., but also it is difficult a decade later to determine exactly how the 1990 analyses were performed. Nonetheless, the work is sufficiently similar that we are confident that the findings, which largely confirm the 1990 results, are valid.
We linked P-sample and E-sample records in the same housing units to provide a basis for calculating rates of within-household omissions for 2000 that could be compared to the 1990 rates from Siegel (1993). We also developed other classifications of linked P-sample and E-sample households.
Table D.1 shows our results: E-sample mail returns received before the cutoff for determining the nonresponse follow-up workload