The HPCOUNTREG Procedure

OUTPUT Statement

  • OUTPUT <output-options> ;

The OUTPUT statement creates a new SAS data set that includes variables created by the output-options. These variables include the estimates of $\mathbf{x}_{i}’\bbeta $, the expected value of the response variable, and the probability of the response variable taking on the current value. Furthermore, if a zero-inflated model was fit, you can request that the output data set contain the estimates of $\mathbf{z}_{i}’\bgamma $ and the probability that the response is zero as a result of the zero-generating process. These statistics can be computed for all observations in which the regressors are not missing, even if the response is missing. By adding observations that have missing response values to the input data set, you can compute these statistics for new observations or for settings of the regressors that are not present in the data without affecting the model fit.

You can specify only one OUTPUT statement. You can specify the following output-options:

OUT=SAS-data-set

names the output data set

COPYVAR=SAS-variable-names
COPYVARS=SAS-variable-names

adds SAS variables to the output data set.

PRED=name

names the variable to contain the predicted value of the response variable.

PROB=name

names the variable to contain the probability that the response variable will take the actual value, Pr($Y=y_ i$).

PROBCOUNT(value1 <value2 …>)

outputs the probability that the response variable will take particular values. Each value should be a nonnegative integer. Nonintegers are rounded to the nearest integer. For value, you can also specify a list of the form X TO Y BY Z. For example, PROBCOUNT(0 1 2 TO 10 BY 2 15) requests predicted probabilities for the counts 0, 1, 2, 4, 5, 6, 8, 10, and 15. This option is not available for the fixed- and random-effects panel models.

PROBZERO=name

names the variable to contain the value of $\varphi _{i}$, which is the probability that the response variable will take the value of 0 as a result of the zero-generating process. This variable is written to the output file only if the model is zero-inflated.

XBETA=name

names the variable to contain estimates of $\mathbf{x}_{i}’\bbeta $.

ZGAMMA=name

names the variable to contain estimates of $\mathbf{z}_{i}’\bgamma $.