The MODELMATRIX Procedure

MODEL Statement

MODEL dependent = <effects> / <model-options>;

The MODEL statement names the dependent variable and the explanatory effects, including covariates, main effects, interactions, and nested effects. If you omit the explanatory effects, the procedure produces a single column of ones.

After the keyword MODEL, the dependent (response) variable is specified, followed by an equal sign. The explanatory effects follow the equal sign.

For information about constructing the model effects, see the section Specification and Parameterization of Model Effects in Chapter 3: Shared Concepts.

The model-options control other aspects of model formation and inference. Table 13.4 summarizes these options.

Table 13.4: MODEL Statement Options

Option	Description
Model Options
INFORMATIVE	Models missing values by using extra indicator variables
NOINT	Suppresses the intercept

Model Options

You can specify the following model-options in the MODEL statement after a slash (/):

INFORMATIVE: models missing values by using extra model effects. These effects consist of dummy variables that take the value 1 when the value of a continuous model variable involved in the effect is missing, and take the value 0 otherwise. The missing value in the original model effect is replaced by the average value of the effect for the nonmissing values. For continuous-by-class effects, such as A*x, where A is a classification variable and x is a continuous variable, informative missingness creates multiple dummy columns and substitutes the effect mean of x that corresponds to the respective level of A. Missing values for classification variables are treated as valid levels. For more information about informative missingness, see the section Informative Missingness in Chapter 3: Shared Concepts.
NOINT: suppresses the intercept term that is otherwise included in the model.

Last updated: December 21, 2018