I am new in this forum.

My question is because in my PhD I am performing SEM with second order factors. I am using SAS system for analysis.

My model consists in 2 second order factors that each explain 7 first order factors, which those explain 20 manifest variables.

We have fixed one factor loading (one path from one of the first order factors towards one manifest variable) to be at 1. And now my question is about the second order factors. Should I estimate their variances (as I do for errors) or should I fix the variance of those second order factors at 1?

Thank you for your help!!!

Carlota