where option represents one of the following: display-optiontest-setand test-set represents one of the following:set-name = [ regions ] set-name = regions where set-name is the name of the set of Lagrange multiplier (LM) tests defined by the regions that follow after the equal sign and regions are keywords denoting specific sets of parameters in the model.
You can use the LMTESTS statement to set display-options or to customize the test-sets for the LM tests. The LMTESTS statement is one of the model analysis statements. It can be used within the scope of the CALIS statement so that the options will apply to all models. It can also be used within the scope of each MODEL statement so that the options will apply only locally. Therefore, different models within a CALIS run can have very different LMTESTS options.
The LM Tests Display Options
The following are the display-options for the LM tests:
DEFAULT
conducts the default sets of LM tests for freeing fixed parameters in the model.
This option is used when you need to reset the default sets of LM tests in the local model. For example, you might have turned off the default LM tests by using the NODEFAULT option in the LMTESTS statement within the scope of PROC CALIS statement. However, for the model under the scope of a particular MODEL statement, you can use this DEFAULT option in the local LMTESTS statement to turn on the default LM tests again.
MAXRANK
sets the maximum number of rankings within a set of LM tests. The actual number of test rankings
might be smaller because the number of possible LM tests within a set might be smaller than the maximum number requested.
NODEFAULT
turns off the default sets of LM tests for freeing fixed parameters in the model.
As a result, only the customized LM tests defined in the test-sets of the LMTESTS statement are conducted and displayed. Note that the LM tests for equality and active boundary constraints are not turned off by this option. If you specify this option in the LMTESTS statement within the scope of the PROC CALIS statement, it will propagate to all models.
NORANK
turns off the ranking of the LM tests. Ranking of the LM tests is done automatically
when the model modification indices are requested. The NORANK option is ignored if you also set the MAXRANK option.
LMMAT
prints the sets of LM tests in matrix form, in addition to the normal LM
test results.
The Customized Sets of LM Tests: Syntax of the Test-sets
In addition to the display-options, you can define customized sets of LM tests as test-sets in the LMTESTS statement. You can define as many test-sets as you like. Ranking of the LM tests will be done individually for each test-set. For example, the following LMTESTS statement requests that the default sets of LM tests not be conducted by the NODEFAULT option. Instead, two customized test-sets are defined.
The first customized set MyFirstSet pulls all possible parameter locations together for the LM test ranking (ALL keyword). The second customized set MySecondSet pulls only the covariances among exogenous variables (COVEXOG keyword) and among errors (COVERR keyword) together for the LM test ranking.
Two different kinds of regions for LM tests are supported in PROC CALIS: matrix-based or non-matrix-based.
The matrix-based regions can be used if you are familiar with the matrix representations of various types of models. Note that defining test-sets by using matrix-based regions does not mean that LM tests are printed in matrix format. It means only that the parameter locations within the specified matrices are included into the specific test-sets for LM test ranking. For matrix output of LM tests, use the LMMAT option in the LMTESTS statement.
Non-matrix-based regions do not assume the knowledge of the model matrices. They are easier to use in most situations. In addition, non-matrix-based regions can cover special subsets of parameter locations that cannot be defined by model matrices and submatrices. For example, because of the compartmentalization according to independent and dependent variables in the LINEQS model matrices, the sets of LM tests defined by the LINEQS matrix-based regions are limited. For example, you cannot use any matrix-based regions to request LM tests for new paths to existing independent variables in the LINEQS model. Such a matrix does not exist in the original specification. However, you can use the non-matrix based regionNEWENDO to refer to these new paths.
The regions for parameter locations are specified by keywords in the LMTESTS statement. Because the regions are specific to the types of models, they are described separately for each model type in the following.
The LM Test Regions for COSAN Models
ALLMAT
specifies all parameter locations in all matrices.
CENTRAL
specifies all parameter locations in the central covariance matrices in all terms.
specifies the parameter locations in the matrices specified in set-of-matrices.
MEANVEC
specifies all parameter locations in the central mean vectors in all terms.
OUTER
specifies all parameter locations in all matrices except for the central covariance matrices and central mean vectors in all terms.
The LM Test Regions for FACTOR Models
The keywords for the matrix-based regions are associated with the FACTOR model matrices. See the section Summary of Matrices in the FACTOR Model for the definitions and properties of these matrices.
Keywords for Matrix-Based Regions
_FACTERRV_ | FACTERRV
specifies the error variances.
_FACTFCOV_ | FACTFCOV
specifies the covariances among factors.
_FACTINTE_ | FACTINTE
specifies the intercepts.
_FACTLOAD_ | FACTLOAD
specifies the factor loadings.
_FACTMEAN_ | FACTMEAN
specifies the factor means.
Keywords for Non-Matrix-Based Regions
ALL
specifies all parameter locations.
COV
specifies the covariances among factors.
COVERR
specifies the covariances among errors.
COVFACT | COVLV
specifies the covariances among factors.
FIRSTMOMENTS
specifies the means of factors and the intercepts.
specifies the effects of independent variables (excluding errors) on dependent variables. Because effects of errors on dependent variables are restricted to ones in the LINEQS model, LM tests on _EQSGAMMA_ and _EQSGAMMA_SUB_ (submatrix of _EQSGAMMA_) are the same.
_EQSNU_ | _EQSNU_SUB_ | EQSNU | EQSNUSUB
specifies the means of independent variables (excluding errors). Because means of errors are restricted to zero in the LINEQS model, LM tests on _EQSNU_ and _EQSNU_SUB_ (submatrix of _EQSNU_) are the same.
_EQSPHI_ | EQSPHI
specifies variances and covariances among all independent variables, including errors.
_EQSPHI11_ | EQSPHI11
specifies variances and covariances among independent variables, excluding errors.
_EQSPHI21_ | EQSPHI21
specifies covariances between errors and disturbances with other independent variables.
_EQSPHI22_ | EQSPHI22
specifies variances and covariances among errors and disturbances.
Keywords for Non-Matrix-Based Regions
ALL
specifies all possible parameter locations.
COV
specifies all covariances among independent variables, including errors and disturbances.
COVERR
specifies covariances among errors or disturbances.
COVEXOG
specifies covariances among independent variables, excluding errors and disturbances.
COVEXOGERR
specifies covariances of errors and disturbances with other independent variables.
COVLV | COVFACT
specifies covariances among latent variables (excluding errors and disturbances).
COVMV | COVOV
specifies covariance among independent manifest variables.
EQUATION | EQUATIONS
specifies all possible linear relationships among variables.
FIRSTMOMENTS
specifies means and intercepts.
INTERCEPTS | INTERCEPT
specifies intercepts of dependent variables.
LV==->LV | LV–>LV
specifies all possible effects of latent factors on latent factors.
LV==>MV | LV–>MV | MV<==LV | MV<–LV
specifies all possible effects of latent factors on manifest variables.
LV<==MV | LV<–MV | MV==>LV | MV–>LV
specifies all possible effects of manifest variables on latent factors.
MEANS | MEAN
specifies the means of independent factors.
MV==>MV | MV–>MV
specifies all possible effects of manifest variables on manifest variables.
NEWDEP | NEWENDO
specifies effects of other variables on the independent variables in the original model.
PATHS | PATH
specifies all possible linear relationships among variables.
The LM Test Regions for LISMOD Models
The keywords for the matrix-based regions are associated with the LISMOD model matrices. See the section Model Matrices in the LISMOD Model for the definitions and properties of these matrices.
Keywords for Matrix-Based Regions
_ALPHA_ | ALPHA
specifies the _ALPHA_ matrix.
_BETA_ | BETA
specifies the _BETA_ matrix.
_GAMMA_ | GAMMA
specifies the _GAMMA_ matrix.
_KAPPA_ | KAPPA
specifies the _KAPPA_ matrix.
_LAMBDA_ | LAMBDA
specifies the _LAMBDAX_ and _LAMBDAY_ matrices.
_LAMBDAX_ | LAMBDAX
specifies the _LAMBDAX_ matrix.
_LAMBDAY_ | LAMBDAY
specifies the _LAMBDAY_ matrix.
_NU_ | NU
specifies the _NUX_ and _NUY_ matrices.
_NUX_ | NUX
specifies the _NUX_ matrix.
_NUY_ | NUY
specifies the _NUY_ matrix.
_PHI_ | PHI
specifies the _PHI_ matrix.
_PSI_ | PSI
specifies the _PSI_ matrix.
_THETA_ | THETA
specifies the _THETAX_ and _THETAY_ matrices.
_THETAX_ | THETAX
specifies the _THETAX_ matrix.
_THETAY_ | THETAY
specifies the _THETAY_ matrix.
Keywords for Non-Matrix-Based Regions
ALL
specifies all model matrices.
COV
specifies all covariance parameters in _THETAY_, _THETAX_, _PHI_, and _PSI_.
COVERR
specifies all covariances for errors or disturbances in _THETAY_, _THETAX_, and _PSI_.
COVFACT | COVLV
specifies all covariances among latent factors in _PHI_ when the -variables exist, and in _PSI_ when the -variables exist without the presence of the -variables.
FIRSTMOMENTS
specifies all intercepts and means in _NUY_, _NUX_, _ALPHA_, and _KAPPA_.
INTERCEPTS | INTERCEPT
specifies all intercepts in _NUY_, _NUX_, and _ALPHA_.
LOADING | LOADINGS
specifies the coefficients in _LAMBDAY_ and _LAMBDAX_.
LV==>LV | LV–>LV
specifies the effects of latent variables on latent variables. Depending on the type of LISMOD model, the _BETA_ and _GAMMA_ might be involved.
LV==>MV | LV–>MV | MV<==LV | MV<–LV
specifies the effects of latent variables on manifest variables. Depending on the type of LISMOD model, the _LAMBDAY_, _LAMBDAX_, and _GAMMA_ matrices might be involved.
MEANS | MEAN
specifies the mean parameters. Depending on the type of LISMOD model, the _ALPHA_ and _KAPPA_ matrices might be involved.
MV==>MV | MV–>MV
specifies effects of manifest variables on manifest variables. Depending on the type of LISMOD model, the _BETA_ and _GAMMA_ matrices might be involved.
PATHS | PATH
specifies all path coefficients. Depending on the type of LISMOD model, the _LAMBDAY_, _LAMBDAX_, _BETA_, and _GAMMA_ matrices might be involved.
The LM Test Regions for MSTRUCT Models
The keywords for the matrix-based regions are associated with the MSTRUCT model matrices. See the section Model Matrices in the MSTRUCT Model for the definitions and properties of these matrices.
Keywords for Matrix-Based Regions
_MSTRUCTCOV_ | _COV_ | MSTRUCTCOV
specifies the _MSTRUCTCOV_ or _COV_ matrix.
_MSTRUCTMEAN_ | _MEAN_ | MSTRUCTMEAN
specifies the _MSTRUCTMEAN_ or _MEAN_ vector.
Keywords for Non-Matrix-Based Regions
ALL
specifies the _MSTRUCTCOV_ (or _COV_) and _MSTRUCTMEAN_ (or _MEAN_) matrices.