13.37. A recent study8 examined the role of family structure in the financial support parents provide for their children’s college education. Using data for 5070 children from 1519 families from the Health and Retirement Study, one aspect of the study modeled the parents’ financial support of tuition costs. Access the article at www.ncbi.nlm.nih.gov/pmc/articles/PMC3461181. Consider the results shown in Table 2 of the article, for this response variable.

(a) Identify the explanatory variables that seem especially relevant, and describe the direction of their estimated effects.

(b) Explain why this analysis used a linear mixed model with random effects. Report the estimated standard deviation of those random effects.

(c) Using the estimated standard deviations in Table 2, find the intraclass correlation. Interpret.