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

parent-focus and child-focus counts separately as was done with the multiplicities. Hence,
although separate models were fit to the parent-focus and child-focus counts, the predicted
values from these models were brought together in a single multivariate imputation.
The spouse-spouse household-level person counts also were hierarchical in that
knowledge of whether a spouse-spouse pair was in the household was required before one could
say that the pair had children. It was somewhat more complicated than the parent-child
hierarchical setup, however, as one model could not represent whether there was a spouse-spouse
pair in the household and whether that pair had children. As a result, the imputations were
conducted in two stages, with the spouse-spouse pair imputations processed first, followed by the
imputations of whether the pairs had children.
The first step for these models was to define respondents, nonrespondents, and the item
response mechanism. For a pair or single respondent to be considered complete, the householdlevel
person counts had to be nonmissing for all the variables being imputed. For the parent-child
pair domains, this meant that the household-level person count had to be nonmissing for the
parent-focus and child-focus 12-to-20 domains. Nonmissing household-level person counts for
these domains automatically guaranteed nonmissing counts for the subset parent-child domains.
A single response propensity adjustment was calculated for all the parent-child domains within
each subsample, and separate response propensity adjustments were calculated for the remainder
of domains. Separate response propensity adjustments were calculated for pairs and single
respondents. For pairs, these adjustments were calculated in order to make the household weights
representative of the entire sample of pairs. For single respondents, household weights also were
used. The adjustments were calculated in order to make the respondent household weights
representative of the entire sample of households that were not part of a pair. Because the
spouse-spouse imputations were conducted in two stages, the response propensity adjustment for
the spouse-spouse-with-children domain adjusted weights to be representative of all spousespouse
pairs. Missing counts for the spouse-spouse-with-children domain were not imputed until
it was known definitively, after the hot-deck step of the PMN imputation, whether a household
had spouse-spouse pairs.
6.4.3.2 Model Building and Determination of Predicted Means
The PMN method is a two-step process. The first step is the modeling step, followed by a
hot-deck step where imputed values replace the missing household-level person counts. The
different attributes of the models are described in this subsection.
Response categories. The response categories for the household-level person count final
response models were simply the household-level person counts, corresponding to each domain,
among the complete data cases. In some cases, two family units were in a household. If these
resulted in unusual household-level person counts, they were excluded from the modeling step,
and were considered nonrespondents for the purposes of weight adjustment. No predicted mean
was calculated in these cases. This occurred with the parent-child parent focus counts and the
spouse-spouse-with-children counts. For the parent-child parent-focus counts, two family units
sometimes resulted in counts of 3 or 4 parents, which were extremely rare levels. The response
categories for the models in the case of the parent-child parent focus counts were, therefore,
limited to 0, 1, or 2 or more. With the spouse-spouse-with-children counts, having two spouse-
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