name conflict error after running collapse command

[Nader Mehri]

Hi,
After running the below collapse command, I got an error on the name conflict (pasted below). Why is this for?

foreach v of varlist TLE_ HLE_ PLE_ trim* exceeds* {
local l "`l' (count) count`v'=`v' (mean) mean`v'=`v' (min) min`v'=`v' (max) max`v'=`v' "
}

collapse `l', by(Age_Group_ sample_label)

error:
countTLE_ = (count) TLE_
countTLE_ = (count) TLE_
name conflict

[Nick Cox]

Try blanking the local macro before the loop:

local l

Otherwise any previous content will just be carried forward.

[Nader Mehri]

Great! Thanks. I have a quickly related question. How does the collapse command treat the missing values? I recall that one of the stata commands, treat them as 0 but not sure if it was collapse.

[Phil Bromiley]

As the documentation says:

Create dataset containing the percentage of observations in each year where the totals are weighted counts of nonmissing gpa and hours
. collapse (percent) gpa hour [fw=number], by(year)

Collapse treats missing data as missing just like almost all other Stata procedures.

The idea of treating missing data as zeros is one of the weird things I find in Excel sometimes.