use https://www.bristol.ac.uk/cmm/media/runmlwin/tutorial, clear
reffadjustsim helpfile examples
Examples 1 & 2 assume the path to the MLwiN executable is set in global MLwiN_path; see help runmlwin
Example 1: Two level continuous response model
(see page 59 of the MLwiN User Manual)
- read in data
- fit model using MLwiN via
runmlwin
///
runmlwin normexam cons standlrt, level1(student: cons) level2(school: cons standlrt) batch
--- Begin MLwiN error log ---
MLN - Software for N-level analysis. Mon 20 Oct 2025 08:54:48
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000003
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000007
--- End MLwiN error log ---
Warning: getversion plugin could not be loaded
MLwiN 3.16 multilevel model Number of obs = 4059
Normal response model (hierarchical)
Estimation algorithm: IGLS
-----------------------------------------------------------
| No. of Observations per Group
Level Variable | Groups Minimum Average Maximum
----------------+------------------------------------------
school | 65 2 62.4 198
-----------------------------------------------------------
Run time (seconds) = 0.06
Number of iterations = 4
Log likelihood = -4658.435
Deviance = 9316.87
------------------------------------------------------------------------------
normexam | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
cons | -.0115051 .039783 -0.29 0.772 -.0894783 .066468
standlrt | .5567305 .019937 27.92 0.000 .5176547 .5958062
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects Parameters | Estimate Std. Err. [95% Conf. Interval]
-----------------------------+------------------------------------------------
Level 2: school |
var(cons) | .0904446 .017924 .0553142 .1255749
cov(cons,standlrt) | .0180414 .0067229 .0048649 .031218
var(standlrt) | .0145361 .0044139 .0058851 .0231872
-----------------------------+------------------------------------------------
Level 1: student |
var(cons) | .5536575 .0124818 .5291937 .5781214
------------------------------------------------------------------------------
/nogui option ignored
ECHO 0
Execution completed
- report coefficient as median with 2.5 & 97.5 percentiles
seed(12345) reffadjustsim cons standlrt, eqn(RP2)
------------------------------------------------------------------------------
cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
standlrt | 1.242541 .4311653 2.607229
------------------------------------------------------------------------------
- report coefficient as mean & Wald-type confidence interval
- Warning: mean and Wald-type confidence are inaccurate in this example
seed(12345) waldtype reffadjustsim cons standlrt, eqn(RP2)
------------------------------------------------------------------------------
cons | Coef. Std. Err. [95% Conf. Interval]
-------------+----------------------------------------------------------------
standlrt | 1.319134 1.22225 -1.076431 3.7147
------------------------------------------------------------------------------
Warning: Coef. & Wald-type conf. interval limits may be inaccurate.
Please compare with default output which reports median & centiles.
- compare with delta-method confidence interval (first refit model)
///
runmlwin normexam cons standlrt, level1(student: cons)
level2(school: cons standlrt) batch
reffadjust4nlcom cons standlrt, eqn(RP2)nlcom `r(beta_standlrt)'
--- Begin MLwiN error log ---
MLN - Software for N-level analysis. Mon 20 Oct 2025 08:54:48
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000004
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000008
--- End MLwiN error log ---
Warning: getversion plugin could not be loaded
MLwiN 3.16 multilevel model Number of obs = 4059
Normal response model (hierarchical)
Estimation algorithm: IGLS
-----------------------------------------------------------
| No. of Observations per Group
Level Variable | Groups Minimum Average Maximum
----------------+------------------------------------------
school | 65 2 62.4 198
-----------------------------------------------------------
Run time (seconds) = 0.04
Number of iterations = 4
Log likelihood = -4658.435
Deviance = 9316.87
------------------------------------------------------------------------------
normexam | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
cons | -.0115051 .039783 -0.29 0.772 -.0894783 .066468
standlrt | .5567305 .019937 27.92 0.000 .5176547 .5958062
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects Parameters | Estimate Std. Err. [95% Conf. Interval]
-----------------------------+------------------------------------------------
Level 2: school |
var(cons) | .0904446 .017924 .0553142 .1255749
cov(cons,standlrt) | .0180414 .0067229 .0048649 .031218
var(standlrt) | .0145361 .0044139 .0058851 .0231872
-----------------------------+------------------------------------------------
Level 1: student |
var(cons) | .5536575 .0124818 .5291937 .5781214
------------------------------------------------------------------------------
_nl_1: [RP2]cov(cons\standlrt)/[RP2]var(standlrt)
------------------------------------------------------------------------------
| Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
_nl_1 | 1.241144 .4275471 2.90 0.004 .4031675 2.079121
------------------------------------------------------------------------------
/nogui option ignored
ECHO 0
Execution completed
- compare with Bayesian posterior distribution
///
runmlwin normexam cons standlrt, level1(student: cons) on) initsprevious seed(121211)
level2(school: cons standlrt) batch mcmc(
mcmcsum, getchains reffadjustsim cons standlrt, eqn(RP2) mcmcsum
/nogui option ignored
ECHO 0
BURNING IN...
Burning in for 50 iterations out of 500
Burning in for 100 iterations out of 500
Burning in for 150 iterations out of 500
Burning in for 200 iterations out of 500
Burning in for 250 iterations out of 500
Burning in for 300 iterations out of 500
Burning in for 350 iterations out of 500
Burning in for 400 iterations out of 500
Burning in for 450 iterations out of 500
Burning in for 500 iterations out of 500
Actual update 50 of 5000, Stored update 50 of 5000
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Actual update 4800 of 5000, Stored update 4800 of 5000
--- Begin MLwiN error log ---
MLN - Software for N-level analysis. Mon 20 Oct 2025 08:54:48
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000006
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.00000a
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000004
--- End MLwiN error log ---
Actual update 4850 of 5000, Stored update 4850 of 5000
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Actual update 4950 of 5000, Stored update 4950 of 5000
Actual update 5000 of 5000, Stored update 5000 of 5000
Execution completed
Warning: getversion plugin could not be loaded
MLwiN 3.16 multilevel model Number of obs = 4059
Normal response model (hierarchical)
Estimation algorithm: MCMC
-----------------------------------------------------------
| No. of Observations per Group
Level Variable | Groups Minimum Average Maximum
----------------+------------------------------------------
school | 65 2 62.4 198
-----------------------------------------------------------
Burnin = 500
Chain = 5000
Thinning = 1
Run time (seconds) = .627
Deviance (dbar) = 9122.42
Deviance (thetabar) = 9031.09
Effective no. of pars (pd) = 91.34
Bayesian DIC = 9213.76
------------------------------------------------------------------------------
normexam | Mean Std. Dev. ESS P [95% Cred. Interval]
-------------+----------------------------------------------------------------
cons | -.010594 .040224 189 0.395 -.0908355 .0678323
standlrt | .5568075 .0200344 839 0.000 .5167302 .5960792
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects Parameters | Mean Std. Dev. ESS [95% Cred. Int]
-----------------------------+------------------------------------------------
Level 2: school |
var(cons) | .0961163 .0199991 2715 .0644542 .1421674
cov(cons,standlrt) | .0190683 .0072205 1713 .0065699 .034989
var(standlrt) | .0153485 .0046893 978 .0078805 .0261361
-----------------------------+------------------------------------------------
Level 1: student |
var(cons) | .5542075 .0123209 4645 .5309043 .578929
------------------------------------------------------------------------------
------------------------------------------------------------------------------
cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
standlrt | 1.266334 .4572121 2.281147
------------------------------------------------------------------------------
Example 2: Multivariate response model
(see page 214 of the MLwiN User Manual)
- read in data
use https://www.bristol.ac.uk/cmm/media/runmlwin/gcsemv1, clear
- fit model using MLwiN via
runmlwin
eq(1)) (csework cons female, eq(2)), ///
runmlwin (written cons female, eq(1)) (cons, eq(2))) ///
level1(student: (cons, eq(1)) (cons, eq(2))) ///
level2(school: (cons, batch
--- Begin MLwiN error log ---
MLN - Software for N-level analysis. Mon 20 Oct 2025 08:54:50
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000005
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000009
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.00000a
--- End MLwiN error log ---
Warning: getversion plugin could not be loaded
MLwiN 3.16 multilevel model Number of obs = 1905
Multivariate response model (hierarchical)
Estimation algorithm: IGLS
-----------------------------------------------------------
| No. of Observations per Group
Level Variable | Groups Minimum Average Maximum
----------------+------------------------------------------
school | 73 2 26.1 104
-----------------------------------------------------------
Run time (seconds) = 0.12
Number of iterations = 4
Log likelihood = -13400.244
Deviance = 26800.488
------------------------------------------------------------------------------
| Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
written |
cons_1 | 49.45213 .9338433 52.96 0.000 47.62183 51.28243
female_1 | -2.50295 .5607219 -4.46 0.000 -3.601945 -1.403955
-------------+----------------------------------------------------------------
csework |
cons_2 | 69.67166 1.171786 59.46 0.000 67.375 71.96831
female_2 | 6.751393 .6706493 10.07 0.000 5.436944 8.065841
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects Parameters | Estimate Std. Err. [95% Conf. Interval]
-----------------------------+------------------------------------------------
Level 2: school |
var(cons_1) | 46.81298 9.18733 28.80615 64.81982
cov(cons_1,cons_2) | 24.87783 8.880358 7.47265 42.28301
var(cons_2) | 75.16623 14.56485 46.61965 103.7128
-----------------------------+------------------------------------------------
Level 1: student |
var(cons_1) | 124.6343 4.349834 116.1088 133.1598
cov(cons_1,cons_2) | 73.00323 4.17829 64.81393 81.19252
var(cons_2) | 180.0982 6.245801 167.8566 192.3397
------------------------------------------------------------------------------
/nogui option ignored
ECHO 0
Execution completed
- report coefficient as median with 2.5 and 97.5 percentiles
seed(12345) reffadjustsim cons_1 cons_2, eqn(RP2)
------------------------------------------------------------------------------
cons_1 | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
cons_2 | .3308853 .1231026 .5395364
------------------------------------------------------------------------------
- report coefficient as mean with Wald-type confidence interval
seed(12345) waldtype reffadjustsim cons_1 cons_2, eqn(RP2)
------------------------------------------------------------------------------
cons_1 | Coef. Std. Err. [95% Conf. Interval]
-------------+----------------------------------------------------------------
cons_2 | .330939 .1065639 .1220777 .5398003
------------------------------------------------------------------------------
Warning: Coef. & Wald-type conf. interval limits may be inaccurate.
Please compare with default output which reports median & centiles.
- compare with delta-method confidence interval (first refit model)
eq(1)) (csework cons female, eq(2)), ///
runmlwin (written cons female, eq(1)) (cons, eq(2))) ///
level1(student: (cons, eq(1)) (cons, eq(2))) ///
level2(school: (cons,
batch
reffadjust4nlcom cons_1 cons_2, eqn(RP2)nlcom `r(beta_cons_2)'
--- Begin MLwiN error log ---
MLN - Software for N-level analysis. Mon 20 Oct 2025 08:54:50
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.000006
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.00000a
/var/folders/1l/w0qjrymd3hb44s3skrzn4w4w0000gn/T//St94086.00000b
--- End MLwiN error log ---
Warning: getversion plugin could not be loaded
MLwiN 3.16 multilevel model Number of obs = 1905
Multivariate response model (hierarchical)
Estimation algorithm: IGLS
-----------------------------------------------------------
| No. of Observations per Group
Level Variable | Groups Minimum Average Maximum
----------------+------------------------------------------
school | 73 2 26.1 104
-----------------------------------------------------------
Run time (seconds) = 0.10
Number of iterations = 4
Log likelihood = -13400.244
Deviance = 26800.488
------------------------------------------------------------------------------
| Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
written |
cons_1 | 49.45213 .9338433 52.96 0.000 47.62183 51.28243
female_1 | -2.50295 .5607219 -4.46 0.000 -3.601945 -1.403955
-------------+----------------------------------------------------------------
csework |
cons_2 | 69.67166 1.171786 59.46 0.000 67.375 71.96831
female_2 | 6.751393 .6706493 10.07 0.000 5.436944 8.065841
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects Parameters | Estimate Std. Err. [95% Conf. Interval]
-----------------------------+------------------------------------------------
Level 2: school |
var(cons_1) | 46.81298 9.18733 28.80615 64.81982
cov(cons_1,cons_2) | 24.87783 8.880358 7.47265 42.28301
var(cons_2) | 75.16623 14.56485 46.61965 103.7128
-----------------------------+------------------------------------------------
Level 1: student |
var(cons_1) | 124.6343 4.349834 116.1088 133.1598
cov(cons_1,cons_2) | 73.00323 4.17829 64.81393 81.19252
var(cons_2) | 180.0982 6.245801 167.8566 192.3397
------------------------------------------------------------------------------
_nl_1: [RP2]cov(cons_1\cons_2)/[RP2]var(cons_2)
------------------------------------------------------------------------------
| Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
_nl_1 | .3309709 .0986417 3.36 0.001 .1376367 .5243051
------------------------------------------------------------------------------
/nogui option ignored
ECHO 0
Execution completed
- compare with Bayesian posterior distribution
runmlwin (written cons female, eq(1)) (csework cons female, eq(2)), /// level1(student: (cons, eq(1)) (cons, eq(2))) /// level2(school: (cons, eq(1)) (cons, eq(2))) /// batch mcmc(on) initsprevious seed(121211) mcmcsum, getchains reffadjustsim cons_1 cons_2, eqn(RP2) mcmcsum
## Example 3: based on xtmixed helpfile
::: {#915cc68e .cell execution_count=13}
``` {.stata .cell-code}
webuse nlswork, clear
version 12: xtmixed ln_w grade age c.age#c.age ttl_exp tenure c.tenure#c.tenure || ///
idcode: tenure, cov(uns) var
version 12: reffadjustsim _cons tenure, eqn(idcode) seed(12345)
(National Longitudinal Survey of Young Women, 14-24 years old in 1968)
Performing EM optimization:
Performing gradient-based optimization:
Iteration 0: Log likelihood = -8985.3816
Iteration 1: Log likelihood = -8966.2878
Iteration 2: Log likelihood = -8965.819
Iteration 3: Log likelihood = -8965.819
Computing standard errors:
Mixed-effects ML regression Number of obs = 28,099
Group variable: idcode Number of groups = 4,697
Obs per group:
min = 1
avg = 6.0
max = 15
Wald chi2(6) = 6767.13
Log likelihood = -8965.819 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
ln_wage | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
grade | .0690318 .0017885 38.60 0.000 .0655264 .0725372
age | .0321872 .0027908 11.53 0.000 .0267174 .037657
|
c.age#c.age | -.0006574 .0000466 -14.09 0.000 -.0007488 -.000566
|
ttl_exp | .0350762 .0011352 30.90 0.000 .0328513 .037301
tenure | .0393576 .0017198 22.88 0.000 .0359868 .0427284
|
c.tenure#|
c.tenure | -.0019926 .0001232 -16.18 0.000 -.0022341 -.0017512
|
_cons | .162264 .044888 3.61 0.000 .0742851 .2502429
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(tenure) | .0005174 .0000566 .0004176 .0006411
var(_cons) | .0632497 .0020808 .0593001 .0674624
cov(tenure,_cons) | .0007165 .0002809 .0001658 .0012671
-----------------------------+------------------------------------------------
var(Residual) | .0815016 .0007978 .0799529 .0830803
------------------------------------------------------------------------------
LR test vs. linear model: chi2(3) = 9168.36 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
tenure | 1.377053 .2240176 2.619103
------------------------------------------------------------------------------
:::
///
mixed ln_w grade age c.age#c.age ttl_exp tenure c.tenure#c.tenure ||
idcode: tenure, cov(uns)_cons tenure, eqn(idcode) seed(12345) reffadjustsim
Performing EM optimization ...
Performing gradient-based optimization:
Iteration 0: Log likelihood = -8985.3816
Iteration 1: Log likelihood = -8966.3961
Iteration 2: Log likelihood = -8965.819
Iteration 3: Log likelihood = -8965.819
Computing standard errors ...
Mixed-effects ML regression Number of obs = 28,099
Group variable: idcode Number of groups = 4,697
Obs per group:
min = 1
avg = 6.0
max = 15
Wald chi2(6) = 6767.13
Log likelihood = -8965.819 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
ln_wage | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
grade | .0690318 .0017885 38.60 0.000 .0655264 .0725372
age | .0321872 .0027908 11.53 0.000 .0267174 .037657
|
c.age#c.age | -.0006574 .0000466 -14.09 0.000 -.0007488 -.000566
|
ttl_exp | .0350762 .0011352 30.90 0.000 .0328513 .037301
tenure | .0393576 .0017198 22.88 0.000 .0359868 .0427284
|
c.tenure#|
c.tenure | -.0019926 .0001232 -16.18 0.000 -.0022341 -.0017512
|
_cons | .162264 .044888 3.61 0.000 .0742851 .2502429
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(tenure) | .0005174 .0000566 .0004176 .0006411
var(_cons) | .0632497 .0020808 .0593001 .0674624
cov(tenure,_cons) | .0007165 .0002809 .0001658 .0012671
-----------------------------+------------------------------------------------
var(Residual) | .0815016 .0007978 .0799529 .0830803
------------------------------------------------------------------------------
LR test vs. linear model: chi2(3) = 9168.36 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
tenure | 1.377053 .224019 2.619103
------------------------------------------------------------------------------
Example 4: based on xtmelogit helpfile
webuse bangladesh, clear
version 12: xtmelogit c_use urban age child* || district: urban , ///
var
cov(uns) version 12: reffadjustsim _cons urban, eqn(district) seed(12345)
(Bangladesh Fertility Survey, 1989)
note: children omitted because of collinearity.
Refining starting values:
Iteration 0: Log likelihood = -1215.8594 (not concave)
Iteration 1: Log likelihood = -1204.0802
Iteration 2: Log likelihood = -1199.7968
Performing gradient-based optimization:
Iteration 0: Log likelihood = -1199.7968
Iteration 1: Log likelihood = -1199.4726
Iteration 2: Log likelihood = -1199.3158
Iteration 3: Log likelihood = -1199.315
Iteration 4: Log likelihood = -1199.315
Mixed-effects logistic regression Number of obs = 1,934
Group variable: district Number of groups = 60
Obs per group:
min = 2
avg = 32.2
max = 118
Integration points = 7 Wald chi2(5) = 97.50
Log likelihood = -1199.315 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
c_use | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
urban | .8157872 .1715519 4.76 0.000 .4795516 1.152023
age | -.026415 .008023 -3.29 0.001 -.0421398 -.0106902
child1 | 1.13252 .1603285 7.06 0.000 .818282 1.446758
child2 | 1.357739 .1770522 7.67 0.000 1.010724 1.704755
child3 | 1.353827 .1828801 7.40 0.000 .9953882 1.712265
children | 0 (omitted)
_cons | -1.71165 .1605617 -10.66 0.000 -2.026345 -1.396954
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
district: Unstructured |
var(urban) | .6663221 .3224714 .2580709 1.7204
var(_cons) | .3897434 .1292458 .2034723 .7465387
cov(urban,_cons) | -.4058846 .1755418 -.7499402 -.0618289
------------------------------------------------------------------------------
LR test vs. logistic model: chi2(3) = 58.42 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
urban | -.5931825 -.9623632 -.2892334
------------------------------------------------------------------------------
webuse bangladesh, clear
meqrlogit c_use urban age child* || district: urban, cov(uns)_cons urban, eqn(district) seed(12345) reffadjustsim
(Bangladesh Fertility Survey, 1989)
note: children omitted because of collinearity.
Refining starting values:
Iteration 0: Log likelihood = -1215.8594 (not concave)
Iteration 1: Log likelihood = -1204.0802
Iteration 2: Log likelihood = -1199.7968
Performing gradient-based optimization:
Iteration 0: Log likelihood = -1199.7968
Iteration 1: Log likelihood = -1199.4726
Iteration 2: Log likelihood = -1199.3158
Iteration 3: Log likelihood = -1199.315
Iteration 4: Log likelihood = -1199.315
Mixed-effects logistic regression Number of obs = 1,934
Group variable: district Number of groups = 60
Obs per group:
min = 2
avg = 32.2
max = 118
Integration points = 7 Wald chi2(5) = 97.50
Log likelihood = -1199.315 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
c_use | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
urban | .8157872 .1715519 4.76 0.000 .4795516 1.152023
age | -.026415 .008023 -3.29 0.001 -.0421398 -.0106902
child1 | 1.13252 .1603285 7.06 0.000 .818282 1.446758
child2 | 1.357739 .1770522 7.67 0.000 1.010724 1.704755
child3 | 1.353827 .1828801 7.40 0.000 .9953882 1.712265
children | 0 (omitted)
_cons | -1.71165 .1605617 -10.66 0.000 -2.026345 -1.396954
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
district: Unstructured |
var(urban) | .6663221 .3224714 .2580709 1.7204
var(_cons) | .3897434 .1292458 .2034723 .7465387
cov(urban,_cons) | -.4058846 .1755418 -.7499402 -.0618289
------------------------------------------------------------------------------
LR test vs. logistic model: chi2(3) = 58.42 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
urban | -.5931825 -.9623632 -.2892334
------------------------------------------------------------------------------
Example 5: based on xtmepoisson helpfile
webuse epilepsy, clear
version 12: xtmepoisson seizures treat lbas lbas_trt lage visit || ///
var intpoints(9)
subject: visit, cov(uns) version 12: reffadjustsim _cons visit, eqn(subject) seed(12345)
(Epilepsy data; progabide drug treatment)
Refining starting values:
Iteration 0: Log likelihood = -672.17188 (not concave)
Iteration 1: Log likelihood = -660.46056
Iteration 2: Log likelihood = -655.86888
Performing gradient-based optimization:
Iteration 0: Log likelihood = -655.86888
Iteration 1: Log likelihood = -655.68217
Iteration 2: Log likelihood = -655.68103
Iteration 3: Log likelihood = -655.68103
Mixed-effects Poisson regression Number of obs = 236
Group variable: subject Number of groups = 59
Obs per group:
min = 4
avg = 4.0
max = 4
Integration points = 9 Wald chi2(5) = 115.56
Log likelihood = -655.68103 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
seizures | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
treat | -.9286588 .4021638 -2.31 0.021 -1.716885 -.1404323
lbas | .8849767 .1312519 6.74 0.000 .6277277 1.142226
lbas_trt | .3379757 .2044442 1.65 0.098 -.0627276 .738679
lage | .4767192 .353622 1.35 0.178 -.2163672 1.169806
visit | -.2664098 .1647096 -1.62 0.106 -.5892347 .0564151
_cons | 2.099555 .2203709 9.53 0.000 1.667636 2.531474
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
subject: Unstructured |
var(visit) | .5314808 .2293851 .2280931 1.238406
var(_cons) | .2514928 .0587892 .1590552 .3976522
cov(visit,_cons) | .0028715 .0887018 -.1709808 .1767238
------------------------------------------------------------------------------
LR test vs. Poisson model: chi2(3) = 324.54 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
visit | .0044339 -.3128618 .3397986
------------------------------------------------------------------------------
///
meqrpoisson seizures treat lbas lbas_trt lage visit || subject: visit, intpoints(9)
cov(uns) _cons visit, eqn(subject) seed(12345) reffadjustsim
Refining starting values:
Iteration 0: Log likelihood = -672.17188 (not concave)
Iteration 1: Log likelihood = -660.46056
Iteration 2: Log likelihood = -655.86888
Performing gradient-based optimization:
Iteration 0: Log likelihood = -655.86888
Iteration 1: Log likelihood = -655.68217
Iteration 2: Log likelihood = -655.68103
Iteration 3: Log likelihood = -655.68103
Mixed-effects Poisson regression Number of obs = 236
Group variable: subject Number of groups = 59
Obs per group:
min = 4
avg = 4.0
max = 4
Integration points = 9 Wald chi2(5) = 115.56
Log likelihood = -655.68103 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
seizures | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
treat | -.9286588 .4021638 -2.31 0.021 -1.716885 -.1404323
lbas | .8849767 .1312519 6.74 0.000 .6277277 1.142226
lbas_trt | .3379757 .2044442 1.65 0.098 -.0627276 .738679
lage | .4767192 .353622 1.35 0.178 -.2163672 1.169806
visit | -.2664098 .1647096 -1.62 0.106 -.5892347 .0564151
_cons | 2.099555 .2203709 9.53 0.000 1.667636 2.531474
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
subject: Unstructured |
var(visit) | .5314808 .2293851 .2280931 1.238406
var(_cons) | .2514928 .0587892 .1590552 .3976522
cov(visit,_cons) | .0028715 .0887018 -.1709808 .1767238
------------------------------------------------------------------------------
LR test vs. Poisson model: chi2(3) = 324.54 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
_cons | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
visit | .0044339 -.3128618 .3397986
------------------------------------------------------------------------------
Example 6: repeated group variable
webuse nlswork, clear
version 12: xtmixed ln_w grade age || idcode: tenure union, cov(uns) || ///
var
idcode: race, cov(uns) version 12: reffadjustsim tenure union, eqn(idcode) sub(1) seed(12345)
version 12: reffadjustsim race _cons, eqn(idcode) sub(2) seed(12345)
(National Longitudinal Survey of Young Women, 14-24 years old in 1968)
Performing EM optimization:
Performing gradient-based optimization:
Iteration 0: Log likelihood = -5208.9293
Iteration 1: Log likelihood = -5196.8989 (not concave)
Iteration 2: Log likelihood = -5176.1013
Iteration 3: Log likelihood = -5174.4196
Iteration 4: Log likelihood = -5171.2001
Iteration 5: Log likelihood = -5171.0595
Iteration 6: Log likelihood = -5171.0493
Iteration 7: Log likelihood = -5171.0492
Computing standard errors:
Mixed-effects ML regression Number of obs = 19,008
Group variable: idcode Number of groups = 4,132
Obs per group:
min = 1
avg = 4.6
max = 12
Wald chi2(2) = 2164.18
Log likelihood = -5171.0492 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
ln_wage | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
grade | .083625 .0022067 37.90 0.000 .0793 .08795
age | .0104518 .0004215 24.80 0.000 .0096256 .0112779
_cons | .2739857 .0306868 8.93 0.000 .2138407 .3341308
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(tenure) | .0007758 .0000666 .0006556 .0009181
var(union) | .0514475 .0041886 .0438594 .0603483
cov(tenure,union) | .0016667 .0004909 .0007044 .0026289
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(race) | .0202217 .0139137 .0052498 .0778921
var(_cons) | .1578058 .031278 .1070066 .2327211
cov(race,_cons) | -.0401861 .022046 -.0833954 .0030232
-----------------------------+------------------------------------------------
var(Residual) | .0583641 .0007602 .0568929 .0598732
------------------------------------------------------------------------------
LR test vs. linear model: chi2(6) = 10154.21 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
tenure | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
union | .0321253 .0121897 .0521846
------------------------------------------------------------------------------
------------------------------------------------------------------------------
race | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
_cons | -.2544331 -.476558 -.1166022
------------------------------------------------------------------------------
union, cov(uns) || idcode: race, ///
mixed ln_w grade age || idcode: tenure
cov(uns)union, eqn(idcode) sub(1) seed(12345)
reffadjustsim tenure _cons, eqn(idcode) sub(2) seed(12345) reffadjustsim race
Performing EM optimization ...
Performing gradient-based optimization:
Iteration 0: Log likelihood = -5208.9293
Iteration 1: Log likelihood = -5199.2605 (not concave)
Iteration 2: Log likelihood = -5175.53 (not concave)
Iteration 3: Log likelihood = -5173.8245
Iteration 4: Log likelihood = -5171.2707
Iteration 5: Log likelihood = -5171.0525
Iteration 6: Log likelihood = -5171.0492
Iteration 7: Log likelihood = -5171.0492
Computing standard errors ...
Mixed-effects ML regression Number of obs = 19,008
Group variable: idcode Number of groups = 4,132
Obs per group:
min = 1
avg = 4.6
max = 12
Wald chi2(2) = 2164.18
Log likelihood = -5171.0492 Prob > chi2 = 0.0000
------------------------------------------------------------------------------
ln_wage | Coefficient Std. err. z P>|z| [95% conf. interval]
-------------+----------------------------------------------------------------
grade | .083625 .0022067 37.90 0.000 .0793 .08795
age | .0104518 .0004215 24.80 0.000 .0096256 .0112779
_cons | .2739857 .0306868 8.93 0.000 .2138407 .3341307
------------------------------------------------------------------------------
------------------------------------------------------------------------------
Random-effects parameters | Estimate Std. err. [95% conf. interval]
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(tenure) | .0007758 .0000666 .0006556 .0009181
var(union) | .0514475 .0041886 .0438595 .0603483
cov(tenure,union) | .0016667 .0004909 .0007044 .0026289
-----------------------------+------------------------------------------------
idcode: Unstructured |
var(race) | .0202217 .0139134 .0052499 .07789
var(_cons) | .1578059 .0312773 .1070075 .2327191
cov(race,_cons) | -.0401862 .0220455 -.0833945 .0030222
-----------------------------+------------------------------------------------
var(Residual) | .0583641 .0007602 .0568929 .0598732
------------------------------------------------------------------------------
LR test vs. linear model: chi2(6) = 10154.21 Prob > chi2 = 0.0000
Note: LR test is conservative and provided only for reference.
------------------------------------------------------------------------------
tenure | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
union | .0321253 .0121897 .0521846
------------------------------------------------------------------------------
------------------------------------------------------------------------------
race | Median 2.5 Percentile 97.5 Percentile
-------------+----------------------------------------------------------------
_cons | -.2544335 -.4765523 -.1166046
------------------------------------------------------------------------------