Hey everybody-
I have been trying to replicate other researchers' factor analysis
measurement model (estimating the relationship between three observed
variables and one latent factor). They ran the model using LISREL. I have tried running the same model, using the same data, using the structural equation modeling feature of Stata 12.
But I get different results.
Here's the code I'm using:
sem (LNC5 -> perprescmc) (LNC5 -> travalonmc) (LNC5 -> chspklngmc) ///
(perprescmc <- _cons@0) (travalonmc <- _cons@0) (chspklngmc <- _cons@0), ///
covstructure(e.perprescmc e.travalonmc e.chspklngmc, zero) nocons ///
trace iterate(400) latent(LNC5) vce(cluster clustid2) ///
var(e.chspklngmc, init(0.125)) ///
var(e.travalonmc, init(0.8)) ///
var(e.perprescmc, init(4))
I emailed the authors, and they suggested the differing results may
be due to the the possibility that a) Stata 12 calculates its standard
errors differently from LISREL and b) LISREL does not use the delta
method, while Stata 12 might use it. Another friend suggested it might
due to the different rotation methods used by the two programs.
Does this sound correct - could these differences between LISREL
and Stata 12 be what's causing me to get different results? If not, are
there other differences between the two programs that might be causing
this?
Thank you for your consideration.
Brent
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