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Re: st: Odd SEM Results
From
Anders Alexandersson <[email protected]>
To
[email protected]
Subject
Re: st: Odd SEM Results
Date
Mon, 5 Aug 2013 11:13:48 -0400
Hi Joe, only the first model from the SEM builder specifies the
options "latent(Intercept Slope ) nocapslatent" which, I guess, might
be why this model has chi2(45) instead of chi2(43) and no output for
_cons in the structural model. What happens if you instead use the
default?
Anders Alexandersson
[email protected]
On Sat, Aug 3, 2013 at 12:38 PM, Joseph Trubisz <[email protected]> wrote:
> Greetings...
>
> I probably am just missing something, but I don't know what.
> I'm attempting to use sembuilder to create the diagram from Acock's SEM book, specifically the example
> as shown on p.188.
>
> If I use sembuilder, it generates the following output:
>
> . sem (Intercept@1 -> bmi01) (Intercept@1 -> bmi02) (Intercept@1 -> bmi03) (Intercept@1 -> bmi05) (Interc
>> ept@1 -> bmi06) (Intercept@1 -> bmi07) (Intercept@1 -> bmi08) (Intercept@1 -> bmi09) (Slope@0 -> bmi01)
>> (Slope@1 -> bmi02) (Slope@2 -> bmi03) (Slope@4 -> bmi05) (Slope@5 -> bmi06) (Slope@6 -> bmi07) (Slope@
>> 7 -> bmi08) (Slope@8 -> bmi09) (_cons -> Intercept) (_cons -> Slope) (male -> Intercept) (male -> Slope
>> ) (wgtc -> Intercept) (wgtc -> Slope) if bmi01!=.|bmi02!=.|bmi03!=.|bmi05!=.|bmi06!=.|bmi07!=.|bmi08!=.
>> |bmi09!=., method(mlmv) latent(Intercept Slope ) var( e.Intercept*e.Slope) nocapslatent noconstant
> note: Missing values found in observed exogenous variables. Using the noxconditional behavior. Specify
> the forcexconditional option to override this behavior.
> Endogenous variables
>
> Measurement: bmi01 bmi02 bmi03 bmi05 bmi06 bmi07 bmi08 bmi09
> Latent: Intercept Slope
>
> Exogenous variables
>
> Observed: male wgtc
>
> Fitting saturated model:
>
> Iteration 0: log likelihood = -30162.223
> Iteration 1: log likelihood = -29297.714
> Iteration 2: log likelihood = -28707.587
> Iteration 3: log likelihood = -28564.929
> Iteration 4: log likelihood = -28557.353
> Iteration 5: log likelihood = -28557.204
> Iteration 6: log likelihood = -28557.204
>
> Fitting baseline model:
>
> Iteration 0: log likelihood = -36523.419
> Iteration 1: log likelihood = -36520.845
> Iteration 2: log likelihood = -36520.836
> Iteration 3: log likelihood = -36520.836
>
> Fitting target model:
>
> Iteration 0: log likelihood = -52919.48 (not concave)
> Iteration 1: log likelihood = -52675.161 (not concave)
> Iteration 2: log likelihood = -52171.219 (not concave)
> Iteration 3: log likelihood = -49397.835 (not concave)
> Iteration 4: log likelihood = -42220.623 (not concave)
> Iteration 5: log likelihood = -39274.796
> Iteration 6: log likelihood = -38652.54
> Iteration 7: log likelihood = -34772.666
> Iteration 8: log likelihood = -32169.128
> Iteration 9: log likelihood = -31367.639
> Iteration 10: log likelihood = -30934.922
> Iteration 11: log likelihood = -30910.018
> Iteration 12: log likelihood = -30909.236
> Iteration 13: log likelihood = -30909.234
>
> Structural equation model Number of obs = 1581
> Estimation method = mlmv
> Log likelihood = -30909.234
>
> ( 1) [bmi01]Intercept = 1
> ( 2) [bmi02]Intercept = 1
> ( 3) [bmi02]Slope = 1
> ( 4) [bmi03]Intercept = 1
> ( 5) [bmi03]Slope = 2
> ( 6) [bmi05]Intercept = 1
> ( 7) [bmi05]Slope = 4
> ( 8) [bmi06]Intercept = 1
> ( 9) [bmi06]Slope = 5
> (10) [bmi07]Intercept = 1
> (11) [bmi07]Slope = 6
> (12) [bmi08]Intercept = 1
> (13) [bmi08]Slope = 7
> (14) [bmi09]Intercept = 1
> (15) [bmi09]Slope = 8
> (16) [bmi01]_cons = 0
> (17) [bmi02]_cons = 0
> (18) [bmi03]_cons = 0
> (19) [bmi05]_cons = 0
> (20) [bmi06]_cons = 0
> (21) [bmi07]_cons = 0
> (22) [bmi08]_cons = 0
> (23) [bmi09]_cons = 0
> --------------------------------------------------------------------------------
> | OIM
> | Coef. Std. Err. z P>|z| [95% Conf. Interval]
> ---------------+----------------------------------------------------------------
> Structural |
> Intercept <- |
> male | 26.90551 .6496371 41.42 0.000 25.63225 28.17878
> wgtc | 6.996785 .6003745 11.65 0.000 5.820072 8.173497
> -------------+----------------------------------------------------------------
> Slope <- |
> male | .3657208 .02104 17.38 0.000 .3244831 .4069584
> wgtc | .0889063 .0194718 4.57 0.000 .0507423 .1270703
> ---------------+----------------------------------------------------------------
> Measurement |
> bmi01 <- |
> Intercept | 1 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi02 <- |
> Intercept | 1 (constrained)
> Slope | 1 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi03 <- |
> Intercept | 1 (constrained)
> Slope | 2 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi05 <- |
> Intercept | 1 (constrained)
> Slope | 4 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi06 <- |
> Intercept | 1 (constrained)
> Slope | 5 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi07 <- |
> Intercept | 1 (constrained)
> Slope | 6 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi08 <- |
> Intercept | 1 (constrained)
> Slope | 7 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi09 <- |
> Intercept | 1 (constrained)
> Slope | 8 (constrained)
> _cons | 0 (constrained)
> ---------------+----------------------------------------------------------------
> Mean |
> male | .4990512 .0125749 39.69 0.000 .474405 .5236975
> wgtc | -.0001655 .0192488 -0.01 0.993 -.0378925 .0375614
> ---------------+----------------------------------------------------------------
> Variance |
> e.bmi01 | 2.618815 .2046736 2.246876 3.052323
> e.bmi02 | 4.086149 .2175673 3.681222 4.535619
> e.bmi03 | 4.674361 .2320231 4.241024 5.151974
> e.bmi05 | 5.778033 .2604252 5.289505 6.311681
> e.bmi06 | 8.181968 .3511234 7.521926 8.899928
> e.bmi07 | 3.794672 .1906747 3.438769 4.187409
> e.bmi08 | 2.92201 .1689406 2.608965 3.272618
> e.bmi09 | 3.308288 .2088301 2.923295 3.743984
> e.Intercept | 324.2532 11.61219 302.2741 347.8304
> e.Slope | .2448578 .0117764 .2228311 .269062
> male | .2499991 .0088918 .2331651 .2680484
> wgtc | .5851282 .0208269 .5456996 .6274057
> ---------------+----------------------------------------------------------------
> Covariance |
> e.Intercept |
> e.Slope | 4.109434 .280162 14.67 0.000 3.560327 4.658542
> -------------+----------------------------------------------------------------
> male |
> wgtc | -.0751429 .0098082 -7.66 0.000 -.0943666 -.0559193
> --------------------------------------------------------------------------------
> LR test of model vs. saturated: chi2(45) = 4704.06, Prob > chi2 = 0.0000
>
>
> However, the output is nothing like what's in the book. However, if I type in
> exactly what's in the book (p.188), I get the correct results as shown below:
>
> . sem (Intercept@1 Slope@0->bmi01) (Intercept@1 Slope@1->bmi02) (Intercept@1 Slope@2->bmi03) (Intercept@1
>> Slope@4->bmi05)(Intercept@1 Slope@5->bmi06)(Intercept@1 Slope@6->bmi07)(Intercept@1 Slope@7->bmi08)(In
>> tercept@1 Slope@8->bmi09) (Intercept Slope<-male wgtc _cons) if bmi01!=.|bmi02!=.|bmi03!=.|bmi05!=.|bmi
>> 06!=.|bmi07!=.|bmi08!=.|bmi09!=.,var(e.Intercept*e.Slope) method(mlmv) noconstant
> note: Missing values found in observed exogenous variables. Using the noxconditional behavior. Specify
> the forcexconditional option to override this behavior.
> Endogenous variables
>
> Measurement: bmi01 bmi02 bmi03 bmi05 bmi06 bmi07 bmi08 bmi09
> Latent: Intercept Slope
>
> Exogenous variables
>
> Observed: male wgtc
>
> Fitting saturated model:
>
> Iteration 0: log likelihood = -30162.223
> Iteration 1: log likelihood = -29297.714
> Iteration 2: log likelihood = -28707.587
> Iteration 3: log likelihood = -28564.929
> Iteration 4: log likelihood = -28557.353
> Iteration 5: log likelihood = -28557.204
> Iteration 6: log likelihood = -28557.204
>
> Fitting baseline model:
>
> Iteration 0: log likelihood = -36523.419
> Iteration 1: log likelihood = -36520.845
> Iteration 2: log likelihood = -36520.836
> Iteration 3: log likelihood = -36520.836
>
> Fitting target model:
>
> Iteration 0: log likelihood = -52919.48 (not concave)
> Iteration 1: log likelihood = -52663.873 (not concave)
> Iteration 2: log likelihood = -52499.164 (not concave)
> Iteration 3: log likelihood = -52371.927 (not concave)
> Iteration 4: log likelihood = -46362.021 (not concave)
> Iteration 5: log likelihood = -34630.285 (not concave)
> Iteration 6: log likelihood = -34303.836 (not concave)
> Iteration 7: log likelihood = -29724.362
> Iteration 8: log likelihood = -29095.8
> Iteration 9: log likelihood = -28787.969
> Iteration 10: log likelihood = -28750.647
> Iteration 11: log likelihood = -28750.02
> Iteration 12: log likelihood = -28750.019
>
> Structural equation model Number of obs = 1581
> Estimation method = mlmv
> Log likelihood = -28750.019
>
> ( 1) [bmi01]Intercept = 1
> ( 2) [bmi02]Intercept = 1
> ( 3) [bmi02]Slope = 1
> ( 4) [bmi03]Intercept = 1
> ( 5) [bmi03]Slope = 2
> ( 6) [bmi05]Intercept = 1
> ( 7) [bmi05]Slope = 4
> ( 8) [bmi06]Intercept = 1
> ( 9) [bmi06]Slope = 5
> (10) [bmi07]Intercept = 1
> (11) [bmi07]Slope = 6
> (12) [bmi08]Intercept = 1
> (13) [bmi08]Slope = 7
> (14) [bmi09]Intercept = 1
> (15) [bmi09]Slope = 8
> (16) [bmi01]_cons = 0
> (17) [bmi02]_cons = 0
> (18) [bmi03]_cons = 0
> (19) [bmi05]_cons = 0
> (20) [bmi06]_cons = 0
> (21) [bmi07]_cons = 0
> (22) [bmi08]_cons = 0
> (23) [bmi09]_cons = 0
> --------------------------------------------------------------------------------
> | OIM
> | Coef. Std. Err. z P>|z| [95% Conf. Interval]
> ---------------+----------------------------------------------------------------
> Structural |
> Intercept <- |
> male | 1.555545 .2436739 6.38 0.000 1.077953 2.033137
> wgtc | 3.759441 .160021 23.49 0.000 3.445806 4.073077
> _cons | 24.85781 .170538 145.76 0.000 24.52356 25.19206
> -------------+----------------------------------------------------------------
> Slope <- |
> male | .0173321 .0271012 0.64 0.522 -.0357853 .0704495
> wgtc | .0459197 .0178505 2.57 0.010 .0109333 .0809062
> _cons | .3430045 .0189564 18.09 0.000 .3058506 .3801584
> ---------------+----------------------------------------------------------------
> Measurement |
> bmi01 <- |
> Intercept | 1 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi02 <- |
> Intercept | 1 (constrained)
> Slope | 1 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi03 <- |
> Intercept | 1 (constrained)
> Slope | 2 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi05 <- |
> Intercept | 1 (constrained)
> Slope | 4 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi06 <- |
> Intercept | 1 (constrained)
> Slope | 5 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi07 <- |
> Intercept | 1 (constrained)
> Slope | 6 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi08 <- |
> Intercept | 1 (constrained)
> Slope | 7 (constrained)
> _cons | 0 (constrained)
> -------------+----------------------------------------------------------------
> bmi09 <- |
> Intercept | 1 (constrained)
> Slope | 8 (constrained)
> _cons | 0 (constrained)
> ---------------+----------------------------------------------------------------
> Mean |
> male | .4990512 .0125749 39.69 0.000 .474405 .5236975
> wgtc | -.0009276 .0192434 -0.05 0.962 -.0386439 .0367888
> ---------------+----------------------------------------------------------------
> Variance |
> e.bmi01 | 2.443884 .191981 2.095144 2.850673
> e.bmi02 | 4.1472 .2157233 3.745229 4.592315
> e.bmi03 | 4.772852 .2325326 4.33818 5.251077
> e.bmi05 | 5.789807 .2596509 5.302625 6.321749
> e.bmi06 | 8.228898 .3520222 7.56708 8.948599
> e.bmi07 | 3.810727 .1909167 3.454322 4.203904
> e.bmi08 | 2.922193 .1687984 2.609396 3.272487
> e.bmi09 | 3.298484 .2089123 2.913418 3.734444
> e.Intercept | 20.5145 .8043478 18.99706 22.15315
> e.Slope | .189059 .0097265 .170925 .2091168
> male | .2499991 .0088918 .2331651 .2680484
> wgtc | .5849257 .0208131 .5455228 .6271748
> ---------------+----------------------------------------------------------------
> Covariance |
> e.Intercept |
> e.Slope | -.0272943 .0635517 -0.43 0.668 -.1518533 .0972647
> -------------+----------------------------------------------------------------
> male |
> wgtc | -.0747626 .0098037 -7.63 0.000 -.0939775 -.0555478
> --------------------------------------------------------------------------------
> LR test of model vs. saturated: chi2(43) = 385.63, Prob > chi2 = 0.0000
>
> Problem: I look at the command not working and comparing it to the command that does
> work and I don't see the difference.
>
> Can anyone point out to me where I might be going wrong?
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