Matrix results, ESEM, SEM, EFA, CFA

[Paul Lokubal]

Hi Statalist members,

When I try to recreate the results on example 2 from the dataset https://essedunet.nsd.no/cms/data/st...lice_stata.zip on Stata, I get the following error on the output: equation cov(Effective,Procfair) not found.

This is the command/code:

// Fitting the same 2-factor CFA model for 6 items separately for
// each country, and collecting some of the results in a table.
levelsof cntry, clean local(countries)
local n_c: word count `countries'
matrix results = J(`n_c',5,.)
matrix rownames results = `countries'
matrix colnames results = Fcorr pGlob pvEFA RMSEA CFI
// Loop over the countries, and collect results:
local i = 0
foreach c of local countries {
local ++i
display "Country: " "`c'"
// 2-factor CFA model
sem (Effective -> plcpvcr plccbrg plcarcr) ///
(ProcFair -> plcrspc plcfrdc plcexdc) if cntry=="`c'", ///
var(Effective@1 ProcFair@1) method(mlmv) iter(100) ///
nolog satopts(nolog) baseopts(nolog)
matrix b=e(b)
estimates store cfa_mod
estat gof, stats(all)
local converged=e(converged)
if(`converged'==1){
matrix results[`i',1] = _b[cov(Effective,ProcFair):_cons]
matrix results[`i',2] = r(p_ms)
matrix results[`i',4] = r(rmsea)
matrix results[`i',5] = r(cfi)
}
// 2-factor EFA model, for comparison
quietly: sem (Effective -> plcpvcr plccbrg plcarcr ///
(plcrspc,init(0)) (plcfrdc,init(0))) ///
(ProcFair -> (plccbrg,init(0)) (plcarcr,init(0)) ///
plcrspc plcfrdc plcexdc) if cntry=="`c'", ///
var(Effective@1 ProcFair@1) method(mlmv) from(b) iter(100)
local converged=e(converged)
if(`converged'==1){
lrtest cfa_mod .
matrix results[`i',3] = r(p)
}
}
//
matlist results, format(%4.3f)

The problem appears to be the way the "matrix results[`i',1] = _b[cov(Effective,ProcFair):_cons]" and the way the matrix is saved: matrix b = e(b). Everything is fine if I drop the option, "matrix results[`i',1] = _b[cov(Effective,ProcFair):_cons]".

Can someone help me with what could be wrong and how I can save the covariance results in my matrix?

Thank you,
Paul