varlist not allowed

[Zhanghaifan Fu]

Dear all,

I am trying to replicate the code provided from the paper (RACIAL DISCRIMINATION AMONG NBA REFEREES by JOSEPH PRICE AND JUSTIN WOLFERS).
From the code in difference-in-difference, I got the error

varlist not allowed

how should I solve it?
below is the beginning of code and the error :

clear *
set mem 600m
set more off
cap log close
log using logs\diffindiff.log, replace
use "/Users/fuzhanghaifan/Desktop/Data/individual_data.dta", clear
keep if sample==1 & min>0

gen mean=1
reg fouls_rate mean
outreg mean using "Results\DiffinDiff", se coefastr 3aster replace

got the error:

. outreg mean using "Results\DiffinDiff", se coefastr 3aster replace
varlist not allowed
r(101);

end of do-file

r(101);

Best

[Nick Cox]

outreg from SSC or the Stata Journal does not need and indeed does not allow a variable name to be specified. .