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Introduction to Categorical Data Analysis

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372 BRIEF SOLUTIONS TO SOME ODD-NUMBERED PROBLEMS<br />

subject are 12.3 times estimated odds of response in those categories for<br />

premarital sex for another randomly selected subject.<br />

b. Estimate of β much larger for GLMM, since a subject-specific estimate and<br />

variance component is large (recall Section 10.1.4).<br />

17. a. At initial time, treatment effect = 0.058 (odds ratio = 1.06), so two groups<br />

have similar response distributions. At follow-up time, the treatment effect =<br />

0.058 + 1.081 = 1.139 (odds ratio = 3.1).<br />

b. LR statistic =−2[−593.0 − (−621.0)] =56. Null distribution is equal<br />

mixture of degenerate at 0 and X 2 1 , and P -value is half that of X2 1 variate,<br />

and is 0 <strong>to</strong> many decimal places.<br />

23. From Section 10.1.4, the effects in marginal models are smaller in absolute value<br />

than effects in GLMMs, with greater difference when ˆσ is larger. Here, the effect<br />

for GLMM is the same for each age group, but diminishes more for the older<br />

age group in the marginal model because the older age group has much larger<br />

ˆσ in GLMM.

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