Hey,

I am running a regression with categorical variables. But I am quite confused why it only shows the second group result?

Code:
gen byte agegroup = 0 if age>=60 & age<.
replace agegroup = 1 if age>=50 & age<60
replace agegroup = 2 if age<50

reg cash_etr i.agegroup tenure lev PPE cash net_CF size tobin roa sales_growth capx xrd cf_vol for_income ch_nol nol for_op ffi_* fyear_* if age<=50, r
outreg2 using main_regression_age.xls, excel stats(coef tstat) bdec(3) tdec(2) symbol(***, **, *) label cti(Cash_ETR) replace addtext(Industry and year effects, YES) nonotes drop(cash_etr fyear_* ffi_* o.*) adjr2

reg gaap_etr i.agegroup tenure lev PPE cash net_CF size tobin roa sales_growth capx xrd cf_vol for_income ch_nol nol for_op ffi_* fyear_*, r
outreg2 using main_regression_age.xls, excel stats(coef tstat) bdec(3) tdec(2) symbol(***, **, *) label cti(GAAP_ETR) append addtext(Industry and year effects, YES) nonotes drop(gaap_etr fyear_* ffi_* o.*) adjr2

reg pbtd i.agegroup tenure lev PPE cash net_CF size tobin roa sales_growth capx xrd cf_vol for_income ch_nol nol for_op ffi_* fyear_*, r
outreg2 using main_regression_age.xls, excel stats(coef tstat) bdec(3) tdec(2) symbol(***, **, *) label cti(PBTD) append addtext(Industry and year effects, YES) nonotes drop(pbtd fyear_* ffi_* o.*) adjr2