Re: st: Simultaneous occurance

[Kyle Hood <kyle.hood@yale.edu>]

If the variables are named x1 and x2, could you not just sum them?

. gen x3 = x1 + x2

Then you get 0 when they are both zero, 1 when they differ, and 2 when 
they are both 1.  If you want to return a 1 when x1 = x2, use

. gen x3 = ( x1 == x2 )

egen group will encode all four possible combinations

. egen x3 = group( x1 x2 )

Kyle



On Tue, 18 Mar 2008, Olga Lyashevskaya wrote:


> Dear all,
>
> There are two binary variables in my sample, where 1
> is presence and 0 is absence of the particular
> characteristic. I want to identify those cases where I
> get either both 0's or both 1's
>
> Any suggestions?
>
> Thank you in advance,
> Olga
>
>
>
>
>
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