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

spouse pairs with children younger than 18 also was an extremely rare category. The response
categories that resulted for the spouse-spouse-with-children models were, therefore, 0 or 1 or
more. Households with two family units did not need to be excluded from the spouse-spouse
models, since having two spouse-spouse pairs in a household, though not common, was not rare.
Covariates in models. The same pool of covariates that was used for the multiplicity
models also was used for the household-level person counts. The same dual set of models were
fitted according to whether the household composition age count variables existed or not.
Naturally, the final set of covariates differed from the initial pool. The final set of covariates that
were used in the models is provided in Appendix Q.
Building of models. The household-level person counts could have a value of 0, which
distinguished them from the multiplicities from a modeling point of view. For the parent-focus
parent-child and the spouse-spouse domains, the models were fitted as multinomial logistic
models. The spouse-spouse-with-children models had only two levels, so binomial logistic
models were fitted to those data. Poisson regression was used to fit the models for the householdlevel
person counts corresponding to the sibling-sibling domains, as well as the child-focus
parent-child domains. The data were underdispersed for a Poisson distribution so that the data
had to be scaled using the observed variance.
Determination of predicted means. Although models were built using respondent pairs
and single respondents where the household-level person counts were known definitively,
predicted means were required for all pairs and for all respondents who were not part of a pair.
Once the models were fitted, predicted means were determined for respondent pairs and single
respondents, as well as item nonrespondents among pairs and singles, using the parameter
estimates from the models.
6.4.3.3 Constraints on Hot-Deck Neighborhoods and Assignment of Imputed
Values
In the same manner as the multiplicity and the pair relationship variables, donors (among
pairs and single respondents) in the hot-deck step of PMN for the counts associated with this
domain were chosen with predicted means, if possible, within delta of the recipient's (whether a
pair or single respondent) predicted mean. The value of delta varied depending on the value of
the predicted means. The values of delta for predicted probabilities are shown in Table 6.8.
Wherever necessary and feasible, logical and likeness constraints (as defined in Section
6.2.4.3) were placed on the membership in the hot-deck neighborhoods. The hot-deck step and
the accompanying constraints are described separately for each of the variables in turn.
In those instances where an imputed value could not be found after loosening all the
likeness constraints, the imputed value was determined by doing a random imputation within
bounds derived from the household composition. One of the situations where this occurred was
when the household had two or more family units in the household. Even though the counts were
not included in the models, no predicted means were calculated. (This occurred with the parentfocus
parent-child counts, as well as the spouse-spouse-with-children counts.) Hence, instead of
matching donors and recipients using predicted means, the imputed value was determined using
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