Hello there !

I am trying to use Stata and check my SEM model for measurement in-variance among two different groups. The issue that i am facing is that my model doesn't concave when i apply NO constrains to it. However as soon as i apply constrains to the measurement intercepts and thereafter to other parameters (e.g. measurement coefficients, structural coefficients) the model concaves. Essentially I would like to assess the model without any constrains and then check for goodness of fit when applying the constrains, however I can't get it to run..What is your idea about that ? I sense that the variability in the measurement intercepts is not "helping" stata to run the model !??


Thanks in advance for your response.
George