Shortening id numbers

[Bahre Kiros]

Dear Stata list,

I have an 18 digit household id number "010101088801601002". I want to shorten it to a 14 digit number "01010101601002" by removing the middle number "8880". How could I do it in Stata? I have been trying with the 'substr' command, but couldn't figure out it yet. Any help? Thank you.

[Øyvind Snilsberg]

if the length of the id and the position of the unwanted substring is fixed you can do,

replace id = substr(id,1,7) + substr(id,12,18)

[Bahre Kiros]

Thanks so much Øyvind Snilsberg. It works well. I have another question: Why do Stata give me different results while I am running the same do-file using the same data on the same PC repeatedly.? Is there a mechanism I can detect this problem? Your usual support is appreciated.

[Nick Cox]

#3 is rather general. One rather general answer is whether anything depends on sorting the dataset, as in some cases that may affect the results you get. I would start a new thread with more information (e.g. examples of what is different).

[Bahre Kiros]

Dear Nick,

Thanks for the feedback. Yes, I use "sort household_id" in each of the sections. Is there anything specific that I need to share here?

[Dimitriy V. Masterov]

Try adding the option

, stable