Questionnaire Dwelling Unit-Level and Person Pair-Level Sampling ...

If the attempt to reconcile differences in the household-level person counts between pair
members was unsuccessful, upper and lower bounds within which the imputed value must reside
were determined from the counts for each pair member and the counts for the screener.
6.4.3 Creation of Imputation-Revised Household-Level Person Count Variables
Because of the difficulty in definitively determining household-level counts in many
cases, imputation was not an uncommon proposition. As with the imputation of pair relationships
and multiplicities, the imputation was conducted using the PMN method described in Appendix
N. In this section, the application of PMN to the imputation of household-level person counts is
described. Since only the household-level person count in the third stage was imputed for each
household, the imputation was univariate in the sense that no sequential models were necessary.
However, in some cases several variables were associated with a single model, as described
below.
6.4.3.1 Setup for Model Building
Household-level person counts of the domains listed in the introduction to Section 6.4
were defined for all respondents, regardless of what pair they belonged to, or even whether they
were within a pair at all. Moreover, since a nonzero count did not depend upon the respondent
being within the relevant age range, no logical constraints on age were necessary. However, the
age of the respondent did have an impact on the final count. The biggest difference in the
presence or absence of particular domains in a household was the presence of youths younger
than 18. This was especially true if there were two or more youths in a household, in which case
the household-level person counts would be considerably different from situations where this
was not the case. As a result, both the pair and single-respondent samples were split by age. For
the pairs, both pair members in one sample were younger than 18, and the remainder of pairs
were in the other sample. For the single respondents, one sample consisted of respondents
younger than 18, and the other consisted of the remainder. Separate imputations were conducted
in the two samples.
Four separate imputations were conducted for the sibling-sibling domains, arising from
four separate models. Unlike the multiplicity counts, no imputations were conducted for the
younger focus sibling-sibling domains. Hence, only two of the sibling-sibling domains had
household-level person counts imputed. However, four separate imputations were required since
the sample was split into two subsamples for both pairs and single respondents.
The parent-child domains were hierarchical, so as with the multiplicities, the imputations
could not have been conducted independently if consistency was to be maintained. Hence, like
the multiplicities, only two models were fitted to the child-parent pairs using just the counts for
children (12- to 20-year-olds). One set of models was for the number of the children who had at
least one parent, and the other set was for the number of parents who had a child aged 12 to 20.
Using the predicted means from these models, a single donor pair was selected from which the
household-level person counts were determined for 12-to-14, 12-to-17, and 12-to-20 child-parent
pair domains. (The household-level person counts for the 15-to-17 child-parent domains were
not determined but could be easily derived.) Since the household-level person counts for specific
domains were not dependent upon the pair relationship, it was not necessary to impute the
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