Mplus Users Guide v6.. - Muthén & Muthén

Special Modeling IssuesObs Coh HD17 HD18 HD19 HD20 HD22 HD23 HD24 HD25 HD261 63 * * 3 4 * * 5 * 64 63 * * 5 7 * * 6 * 35 63 * * 5 8 * * 7 * 96 64 * 3 6 * * 5 * 9 *8 64 * 4 9 * * 8 * 6 *10 64 * 3 9 * * 8 * 5 *12 65 6 5 * * 5 * 5 * *13 65 5 5 * * 5 * 5 * *14 65 4 5 * * 6 * 7 * *15 65 4 5 * * 5 * 4 * *The model is specified in the MODEL command using the new variableshd17 through hd26 instead of the original variables hd82, hd83, hd87,and hd89. Note that there is no hd21 because no combination of surveyyear and birth cohort represents this age. The data are analyzed usingthe missing by design feature.CATEGORICAL MEDIATING VARIABLESThe treatment of categorical mediating variables in model estimationdiffers depending on the estimator being used. Consider the followingmodel:x -> u -> ywhere u is a categorical variable. The issue is how is u treated when it isa dependent variable predicted by x and how is it treated when it is anindependent variable predicting y. With weighted least squaresestimation, a probit regression coefficient is estimated in the regressionof u on x. In the regression of y on u, the continuous latent responsevariable u* is used as the covariate. With maximum likelihoodestimation, either a logistic or probit regression coefficient is estimatedin the regression of u on x. In the regression of y on u, the observedvariable u is used as the covariate. With Bayesian estimation, a probitregression coefficient is estimated in the regression of u on x. In theregression of y on u, either the observed variable u or the latent responsevariable u* can be used as the covariate using the MEDIATOR option ofthe ANALYSIS command.439