(* PS6.12  using DATA6-1 for Ramsey's RESET test - Example 6.9 *)
ols UNITCOST const OUTPUT INPCOST 
(* generate estimated Y and its powers *)
genr yhat1=UNITCOST-uhat
genr yhat2 = yhat1*yhat1
genr yhat3=yhat1*yhat2
genr yhat4=yhat2*yhat2
list
(* estimated model with new variables *)
ols UNITCOST const OUTPUT INPCOST yhat2 yhat3 yhat4  
omit yhat2 yhat3 yhat4  
(* Repeat example with the square of OUTPUT added to the model *)
square OUTPUT 
ols UNITCOST const OUTPUT INPCOST sq_OUTPU 
genr yhat5=UNITCOST-uhat
genr yhat6 = yhat5*yhat5
genr yhat7=yhat5*yhat6
genr yhat8=yhat6*yhat6
list
ols UNITCOST const OUTPUT INPCOST sq_OUTPU yhat6 yhat7 yhat8  
omit yhat6 yhat7 yhat8  
