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Niki Su posted on Thursday, February 01, 2018  11:42 pm



I want to run a 111 MSEM with one slope fixed and I don't know how to write the script to estimate the indirect effect. Here is my script: model: %within% m on x(aw); sby on m; scy on x; %between% m on x(ab); y on m(bb); y on x; [sb](bw); 

Niki Su posted on Friday, February 02, 2018  2:01 am



One more question, in my experiment. x is a withinsubject variable with 2 levels. Thus x has no betweengroup variation. Can I estimate the indirecr effect through a model in which x is't claimed as "Within are"? 

Niki Su posted on Friday, February 02, 2018  5:38 am



Following the last question, since x only has withingroup variation, the mediation effect must occur strictly at the withingroup level, and there must be no Between indirect effect though both m and y have betweengroup and withingroup variation. Then the script of the 111 MSEM can be the following: within=x; analysis:type is twolevel random; model: %within% m on x(aw); !The slope is fixed because the correlation of random slope and intercept is 1. sby on m; scy on x; %between% !m on x(ab); The path is commented out because x only has withingroup variation. y on m(bb); !y on x; The path is commented out because x only has withingroup variation. [sb](bw); model constraint: new(indw); indw=aw*bw; Please tell me whether I am right. Thank you very much. 


This is correct. There is no added covariance term for the indirect effect because m on x does not have a random slope. 

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