21.06.2014 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

6.2.4.3 Constraints on Hot-Deck Neighborhoods <strong>and</strong> Assignment of Imputed<br />

Values<br />

If possible, donor pairs in the hot-deck step of PMN were chosen with predicted means<br />

within delta 17 of the recipient pair's predicted mean(s), where the value(s) of delta varied<br />

depending upon the value of the predicted means. In this case, delta was defined as 5 percent of<br />

the predicted probability if the probability was less than 0.5, <strong>and</strong> 5 percent of 1 minus the<br />

predicted probability if the probability was greater than 0.5. This allowed a looser delta for<br />

predicted probabilities close to 0.5 <strong>and</strong> a tighter delta for predicted probabilities close to 0 or 1.<br />

The range of values for delta across various predicted probabilities is shown in Table 6.8. If no<br />

donor pairs were available with predicted means within delta of the recipient pair's predicted<br />

mean, the neighborhood was ab<strong>and</strong>oned, <strong>and</strong> the donor pair with the closest predicted mean was<br />

chosen.<br />

Table 6.8 Values of Delta for Various Predicted Probabilities<br />

Predicted Probability (p)<br />

Delta<br />

p < 0.5<br />

0.05*p<br />

p > 0.5<br />

0.05*(1-p)<br />

In general, the members of the neighborhoods were restricted to satisfy two types of<br />

constraints: "logical constraints" <strong>and</strong> "likeness constraints." Constraints that made the imputed<br />

values consistent with preexisting values of other variables were called logical constraints <strong>and</strong><br />

were required for the c<strong>and</strong>idate donor pair to be a member of the neighborhood. Likeness<br />

constraints were implemented to make donor pairs <strong>and</strong> recipient pairs as much alike as possible.<br />

Although logical constraints could not have been loosened, likeness constraints could have been<br />

loosened if they had forced the donor pool to be too sparse. Details of these imputation<br />

procedures are provided in Appendix N.<br />

In addition to the likeness constraint defined by delta, other likeness constraints also were<br />

included in the neighborhoods. These constraints follow:<br />

Older pair member age constraint, 26+-year-old pair members. The 26+ age group,<br />

associated with age group pairs 7 through 10, was split up into three groups: 26 to 34, 35 to 49,<br />

<strong>and</strong> 50+. This was most useful to delineate child-parent pairs.<br />

Marital status constraints. Each respondent's marital status, as entered in the core section<br />

of the questionnaire, was closely related to the relationship between the pair members. 18 This<br />

marital status variable had four levels among respondents aged 15 or older: married, widowed,<br />

separated or divorced, <strong>and</strong> never married. Marital status likeness constraints combined the<br />

information from this variable for both pair members, where the levels were collapsed in<br />

17 "Delta" refers to the value that defined the neighborhood of donor pairs that were "close" to the recipient<br />

pair. The difference between the predicted mean of the recipient pair <strong>and</strong> the predicted means of the donor pairs<br />

must have been less than delta. See Appendix N for more details.<br />

18 <strong>Pair</strong>s that included a pair member with an imputed marital status were not eligible to be donor pairs. If a<br />

recipient pair had a pair member with an imputed marital status, then donor pairs had any marital status, unless one<br />

of the pair members in the recipient pair had a nonimputed marital status indicating married, widowed, or divorced.<br />

42

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!