# PS6.11 for Example 6.8
open data6-4
logs WAGE  
ols l_WAGE const EDUC EXPER AGE 
genr ut = $uhat
square EDUC EXPER AGE  
ols ut const EDUC EXPER AGE sq_EDUC sq_EXPER sq_AGE  
genr LM = $nrsq
pvalue X 3 LM
