(* PS8.4, using DATA8-1, for the White's test of Example 8.5 *)
genr LNSALARY=ln(SALARY)
(* generate squares and cross-products *)
genr YRS2 = YEARS*YEARS
genr YRS3 = YRS2*YEARS
genr YRS4 = YRS2*YRS2
(* estimate log quadratic model *)
ols LNSALARY const YEARS YRS2 
(* save squared residuals *)
genr usq=uhat*uhat
(* auxiliary regression *)
ols usq const YEARS YRS2 YRS3 YRS4 
(* compute LM test statistic and p-value *)
genr LM=$nrsq
pvalue X 4 LM

