Hi, I have a question about the path analysis with Mplus. In example 3.11 of Mplus user's guide, there are two variables y1 and y2 fitted by x1, x2, and x3, and then x2, y1, and y2 are defined as independent variables to fit the last variable y3. I am wondering, if there is no variable y3, is this path analysis still available? Meanwhile, the analysis is just stopped by y1 and y2, which are defined as the terminal outcome variables. I tried this program by withdrawing the last line "y3 on y1 y2 x2" in model statement, and still obtained an output. However, I am wondering whether this structure is reasonable to do path analysis. There is no obvious information about whether this model design is available or unavailable while searching on the Internet, so hope I can get some suggestions from here. Any comment is appreciated. Thank you.
THE STANDARD ERRORS OF THE MODEL PARAMETER ESTIMATES MAY NOT BE TRUSTWORTHY FOR SOME PARAMETERS DUE TO A NON-POSITIVE DEFINITE FIRST-ORDER DERIVATIVE PRODUCT MATRIX. THIS MAY BE DUE TO THE STARTING VALUES BUT MAY ALSO BE AN INDICATION OF MODEL NONIDENTIFICATION. THE CONDITION NUMBER IS -0.919D-17. PROBLEM INVOLVING PARAMETER 9.
Is it because my third dependent variable is the interaction of the other two ??