The HPCOUNTREG Procedure

The BOUNDS statement imposes simple boundary constraints on the parameter estimates. You can specify any number of BOUNDS statements.

Each bound is composed of parameter names, constants, and inequality operators as follows:

Each item is a constant, a parameter name, or a list of parameter names. Each operator is <, >, <=, or >=. Parameter names are as shown in the Parameter column of the "Parameter Estimates" table. Please refer to the section Parameter Naming Conventions for the RESTRICT, TEST, BOUNDS, and INIT Statements for more information on how parameters are named in the BOUNDS statement.

You can use both the BOUNDS statement and the RESTRICT statement to impose boundary constraints. However, the BOUNDS statement provides a simpler syntax for specifying these kinds of constraints. For more information, see the section RESTRICT Statement.

The following BOUNDS statement illustrates the use of parameter lists to specify boundary constraints. It constrains the estimates of the parameter for z to be negative, the parameters for x1 through x10 to be between 0 and 1, and the parameter for x1 in the zero-inflation model to be less than 1.

   bounds z < 0,
          0 < x1-x10 < 1,
          Inf_x1 < 1;