The Bicentennial Census New Directions for Methodology in 1990: 30th Anniversary Edition (2015) / Chapter Skim
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8 Measuring the Completeness of the 1990 Census
8 Measuring the Completeness of the 1990 Census
Pages 283-318
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From page 283... ...
We later suggest a fifth method for coverage evaluation, which we call systematic observation. Systematic observation is a close relative of ethnographic studies, or resident observation.
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From page 284... ...
Through 1970, the ensus C B ureau's judgment was that demographic analysis provided the best estimates of undercoverage, and these estimates were generally used in discussions of the undercount. Subsequent events, particularly the large level of presumed undocumented immigration, caused the Census Bureau to anticipate that this would no longer be true in 1980 and to rely on the PEP for coverage evaluation of the 1980 census.
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From page 285... ...
Then follows a description and assessment of a recent Census Bureau position paper, by Kirk Wolter, on plans for coverage evaluation and adjustment in the 1990 decennial census. Current Program for Testing and Research of Coverage Evaluation 1985 Pretest of Post-Enumeration Survey Methodology The Census Bureau experienced a number of problems in conducting the 1980 Post-Enumeration Program, and it is planning a pretest in 1985 on post-enumeration survey (PES)
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From page 286... ...
As a result of the panel's recommendations, the Census Bureau decided to focus its pretest of Post-Enumeration Survey Methodology on the areas of computer matching and nonresponse. 1 Rules on whether the current or the listed resident should be enumerated in the PES refer to the problem of movers and whether new residents or the residents listed as present on Census Day are counted.
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From page 287... ...
Other lists, for example, police blotters or records of local hospital admissions. Since this pretest will not form a composite list, there will be no testing of this important component of administrative list-based coverage evaluation programs.
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From page 288... ...
The panel feels that the Forward Trace Study is likely to yield useful information as to the feasibility of using a reverse record check to evaluate the completeness of coverage of the 1990 decennial census, and therefore should be completed.
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From page 289... ...
Restrictions come with the use of the Current Population Survey, including the sampling design, the timing of the survey, the type of interviewing and follow-up used, the questions asked, etc. A survey dedicated to coverage evaluation will give the Census Bureau the opportunity to consider many possibilities, including: (1)
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From page 290... ...
iii. Wolter strongly puts forward the post-enumeration survey as the key element of the 1990 coverage evaluation program, to the ex clusion of methods such as administrative records, reverse record checks, and systematic observation.
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From page 291... ...
Reverse record checks, administrative list methods, and systematic observation are real possibilities for measuring undercount for these groups. The panel feels that the exclusive reliance on a post-enumeration survey methodology for coverage evaluation in 1990 is, at this time, premature.
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From page 292... ...
The Census Bureau has completed a number of studies based on the 1980 census that, when summarized, promise to provide useful information pertaining to coverage evaluation and possible adjustment of future censuses. There are a number of other studies as yet uncompleted or un reported that would also yield important information on strategies for coverage evaluation.
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From page 293... ...
THE 1990 DEMOGRAPHIC ANALYSIS PROGRAM: POSSIBLE IMPROVEMENTS Demographic analysis requires data from sources, independent of the current census, to estimate the number of persons in a given age-race-sex category. The corresponding number recorded in the census can be evaluated by comparison with the demographic approximation.
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From page 294... ...
Thus, it no longer provided reasonable measures of the differential undercount by race. A useful modification of the procedure seems to be to apply demographic analysis separately to persons born in the United States and to the foreign born, provided the reliability of reporting of country of birth is high enough.
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From page 295... ...
A portion of this movement could be inferred from immigration information from other countries. Estimates of emigration could also be derived, as a by-product, from a reverse record check, if one is carried out in conjunction with the 1990 census, or perhaps by a multiplicity-sampling approach incorporated in the Current Population Survey.
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From page 296... ...
(5) The reverse record check provides a direct estimate of the number of emigrants since the last census, which can be used to overcome one of the significant data gaps of demographic estimation -- both to evaluate the current census and as a benchmark for its inter censal population estimation.
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From page 297... ...
As indicated in Recommendation 8.1, the panel is concerned that a reverse record check be given more attention as a potential coverage evaluation methodology in 1990. Assuming that Recommendation 8.1 is persuasive and the decision is made to proceed in 1990 with a reverse record check in either a testing mode or as a primary coverage evaluation program, it is then necessary to know very soon which of the three versions of tracing will be used.
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From page 298... ...
Although the sampling frame for the Current Population Survey is not independent of the decennial census, it undergoes sufficient changes over the intercensal period so that the listing of addresses used is fairly distinct from that of the decennial census (see Bureau of the Census, 1978a)
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From page 299... ...
Reduction in the Level of Survey Nonresponse Like any sample survey, the survey used for the Post-Enumeration Program will suffer from an imperfect sampling frame and interview refusals. As mentioned in Chapter 4, over 4 percent of the Current Population Survey interviews in April 1980 were refusals.
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From page 300... ...
Should a separate survey be used, it might still be highly desirable to employ experienced Current Population Survey interviewers during the non-CPS weeks. Reduction in the Percentage of Unresolved Matches In the 1980 Post-Enumeration Program, after completing a Current Population Survey interview, Census Bureau staff geocoded the address of each sample residence to determine the enumeration district in which that residence should have been placed in the 1980 decennial census.
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From page 301... ...
Fractional matching is therefore merely a model relating match status to likelihoods from some model, for example, the Fellegi-Sunter model. Assuming a computer matching success rate of 60-70 percent -- perhaps an optimistic rate -- this, without clerical assistance, would result in a massive imputation of match status.
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From page 302... ...
It was also used to offset the Current Population Survey sample cases that could not be matched to the census within the local area to which matching was restricted, often as a result of faulty determination of census geography, or indistinct addresses. As described above in Chapter 4, the form of the dual-system estimate used in the 1980 Post-Enumeration Program for a particular demographic stratum was as follows (see Cowan and Fay, 1984)
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From page 303... ...
. The idea is to use an independent survey in the Post-Enumeration Program in place of the Current Population Survey.
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From page 304... ...
Estimation of the Degree of Independence Between Survey and Census A major and untested assumption of the 1980 Post-Enumeration Program is that, for each person, the events of being included in the census and the Current Population Survey are independent. However, there is evidence supporting the belief that many of the types of individuals missed in the census are also missed disproportionately by the Current Population Survey and, for that matter, by any type of household survey technique.
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From page 305... ...
Therefore, an important factor is the gathering of information for individuals missed by both the census and the post-enumeration survey. A method that should be tested for its potential to count some of the individuals who typically escape the counting method used by censuses and surveys is the reverse record check.
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From page 306... ...
It has been suggested that earlier months of the Current Population Survey could be used, which would be ready for matching at the time of the decennial census. The January through March Current Population Surveys would be possibilities, with March having the additional advantage of containing a wealth of characteristics information that could be used for purposes of content evaluation and possibly modeling.
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From page 307... ...
Of key importance from the point of view of coverage evaluation are attempts to generate, very early on, machine-readable records of the basic identification of enumerated persons and households, adequate for computer matching. In order to exploit the potential existence, at an early date, of both census and post-enumeration survey records in machine-readable form, effective computer matching algorithms have to be developed.
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From page 308... ...
Of course stochastic response errors in both the census and the post-enumeration survey will undoubtedly induce some matching variance. The estimation of this variance is technically feasible but would probably introduce serious operational difficulties when superimposed on the other rigorous requirements of a coverage evaluation program.
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From page 309... ...
The different objectives of the proposed study require the use of a term different from the anthropological one of resident observers. We have adopted the term systematic observers.
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From page 310... ...
The identification of the reason for noncompliance, especially with respect to different population subgroups, is vital for understanding how coverage improvement and coverage evaluation might be improved to help minimize the problem of differential undercoverage. Observers of this type could be placed in a number of different types of localities.
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From page 311... ...
As full-time employees of the Census Bureau, they would be instructed in procedures for data collection and in the techniques of systematic observation. At some point in the census procedure, presumably a few weeks before Census Day, the systematic observers would prepare a listing of households in their designated area, and indicate the household composition.
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From page 312... ...
Systematic observer studies are expensive, but the total cost of including in the census a broad sample of the type described might be comparable to many of the activities used in the 1980 census to increase coverage. The cost of a large systematic observer study is also on the same order of magnitude as the post-enumeration studies being considered as a part of a census evaluation and adjustment program.
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From page 313... ...
provided a lower bound for the estimates of illegal migrants by estimating all those who were counted during the 1980 census. Their final figure of about 2 million is reasonably close to other estimates of total illegal migrants residing in the United States during the 1970s.
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From page 314... ...
of Mexican illegal migrants. Range of estimates: For 1978, 1.1 1.7 million of Mexican illegal migrants (net)
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From page 315... ...
. Analogous procedures have been used through the matching of different sources of information such as the United States census, the Current Population Survey, and a variety of administrative records (Lancaster and Scheuren, 1978)
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From page 316... ...
However, even in the latter case, some methods of census coverage evaluation (e.g., demographic methods and reverse record checks) are affected by errors that vary directly with concentration of illegal residents, since migration records and statistics do not include illegal migrants.
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From page 317... ...
Based on these assumptions, a study containing 400 resident observers would yield a coefficient of variation for the sample mean miss rate of about 5 percent. If the cost per systematic observer were $12,000, the direct cost of the systematic observers for 400 sampling units would be approximately 4.8 million dollars.
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