I find that Mplus adds correlations unspecified by my model. In the User's Guide it reads that correlations between exogenous variables are included automatically. Although I do not fully understand the rationale behind this and I wouldn't mind adding these correlations myself, I understand what is going on.
I find, however, that also correlations between exogenous and (latent) endogenous variables are added.
I wonder why this is and what I can do to prevent this, other than setting the loadings @0.
In this part of the input I have fixed all correlations to 0 that aren't between variables/factors in a 'column'. I realize that variables/factors that aren't in the same column can be related, but I prefer thinking of these as causal relationships, indicated by 'on' statements that I plan to add if indicated by the Modification Indices.
model: f1 by y1 y2; f2 by y3 y4; f3 by y5 y6; f4 by y7 y8; f5 by y9 y10; f6 by y11 y12; f7 by y13 y14; f8 by y15 y16; f9 by y17 y18; f1 on x1 x2 x3 x4 x5; f2 on x1 x2 x3 x4 x5; f3 on x1 x2 x3 x4 x5; f4 on x1 x2 x3 x4 x5; f5 on f1 f2 f3 f4; f6 on f1 f2 f3 f4; f7 on f1 f2 f3 f4; f8 on f5 f6 f7; f9 on f8; x1 with x2 x3 x4 x5; x2 with x3 x4 x5; x3 with x4 x5; x4 with x5; f1 with f2 f3 f4; f2 with f3 f4; f3 with f4; f5 with f6 f7; f6 with f7; x1-x5 with f1-f9@0; f1-f4 with f5-f9@0; f5-f7 with f8-f9@0; f8 with f9@0;
When I add one WITH statement between just two variables MPLUS sometimes automatically outputs many WITH statements among other variables in the model. When I remove the WITH statement all the others are no longer included in the output. Is this a bug or something I haven't picked up on? I have version 3.12. Thanks for your help.