st: Speaking Stata: by varlist

[Zhehui Luo <luozhehu@msu.edu>]

Dear Statalisters,

In Stata, the

bysort varlist: list varlist if _N>1

is supposed to find duplicates with respect to the bysort varlist.

I have a data set, and I know by the ID variable there is no duplicates, 
because if I use

bys ID: gen count=_N
tab count

I get count all equal to 1.

However, if I use

bys ID: list varlist if N>1

Stata starts to list every observation from the top.

Why is this happening?

Thanks.

Luo


tab count


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