sysuse auto.dta //Nestreg reg price mpg reg price mpg weight reg price mpg weight length trunk nestreg: reg price (mpg) (weight) (length trunk) nestreg, store(model): reg price (mpg) (weight) (length trunk) estimate restore model1 outreg2 using results.xls,replace estimate restore model2 outreg2 using results.xls,append estimate restore model3 outreg2 using results.xls pcorr price mpg weight length trunk bys foreign: nestreg : reg price (mpg) (weight) (length trunk) //Hireg //ssc install hireg hireg price (mpg) (weight) (length trunk)