How to compute Wilcoxon rank-sum test in Stata?

Question

I would like to compute the Wilcoxon rank-sum test in Stata for two countries of my sample with the dummyvalue 3 and 6.

Can anyone give the right code for Stata?

Answer 1

Something like:
. ranksum y if country==3 | country==6, by(country)
or, slightly more concisely,
. ranksum y if inlist(country,3,6), by(country)
(where y is the outcome variable you wish to test).