CPANEL Procedure

The RESTRICT statement specifies linear equality restrictions on the parameters in the previous MODEL statement. There can be as many unique restrictions as the number of parameters in the preceding MODEL statement. Multiple RESTRICT statements are understood as joint restrictions on a model’s parameters. Restrictions on the intercept are obtained by the use of the INTERCEPT keyword. RESTRICT statements before the first MODEL statement are automatically associated with the first MODEL statement, in addition to any RESTRICT statements that follow it but precede subsequent MODEL statements.

Currently, only linear equality restrictions are permitted in PROC CPANEL. Tests and restriction expressions can be composed of only algebraic operations that involve the addition symbol (+), subtraction symbol (–), and multiplication symbol (*).

The following statements illustrate the use of the RESTRICT statement:

proc cpanel data =  mylib.a;
   id csid tsid;
   model y = x1 x2 x3;
   restrict x1 = 0, x2 * .5 + 2 * x3 = 0;
   restrict intercept = 1;
run;

If you are fitting a dynamic panel model, you can place restrictions on lags of the dependent variable by referencing the name of the dependent variable, followed by an underscore and the lag order. For example:

proc cpanel data =  mylib.a;
   model sales = price / dyndiff;
   restrict sales_1 = 0.5;
run;

Note that a RESTRICT statement cannot include a division sign in its formulation.