The OUTEST= data set contains all the parameters that are estimated in a MODEL statement. The OUTEST= option can be used when the PROC MDC call contains one MODEL statement. There are additional restrictions. For the HEV and multinomial probit models, you need to specify exactly all possible elements of the choice set, since additional parameters (for example, SCALE1 or STD1) are generated automatically in the MDC procedure. Therefore, the following SAS statements are not valid when the OUTEST= option is specified:
proc mdc data=a outest=e;
model y = x / type=hev choice=(alter);
run;
You need to specify all possible choices in the CHOICE= option since the OUTEST= option is specified as follows:
proc mdc data=a outest=e;
model y = x / type=hev choice=(alter 1 2 3);
run;
When the NCHOICE= option is specified, no additional information about possible choices is required. Therefore, the following SAS statements are correct:
proc mdc data=a outest=e;
model y = x / type=mprobit nchoice=3;
run;
The nested logit model does not produce the OUTEST= data set unless the NEST statement is specified.
Each parameter contains the estimate for the corresponding parameter in the corresponding model. In addition, the OUTEST= data set contains the following variables:
the name of the dependent variable
the estimation method
the label of the MODEL statement if one is specified, or blank otherwise
a character variable that indicates whether the optimization process reached convergence or failed to converge: 0 indicates that the convergence was reached, 1 indicates that the maximum number of iterations allowed was exceeded, 2 indicates a failure to improve the function value, and 3 indicates a failure to converge because the objective function or its derivatives could not be evaluated or improved, or linear constraints were dependent, or the algorithm failed to return to feasible region, or the number of iterations was greater than prespecified.
the name of the row of the covariance matrix for the parameter estimate, if the COVOUT option is specified, or blank otherwise
the log-likelihood value
standard error of the parameter estimate, if the COVOUT option is specified
PARMS for observations that contain parameter estimates, or COV for observations that contain covariance matrix elements
The OUTEST= data set contains one observation for the MODEL statement giving the parameter estimates for that model. If the COVOUT option is specified, the OUTEST= data set includes additional observations for the MODEL statement giving the rows of the covariance matrix of parameter estimates. For covariance observations, the value of the _TYPE_ variable is COV, and the _NAME_ variable identifies the parameter associated with that row of the covariance matrix.