st: Problem using asclogit regression

[Muhammad Akram <aasim548@hotmail.com>]

Dear Stata Users,

I am trying to use asclogit model for my estimation purpose. I use command like this

 

asclogit  val pris menuvariation quetime, case(id) alternative(alternativ123)

 

This command comes out with the error 

"variable alternativ123 has replicate levels for one or more cases; this is not allowed"

 

My variables look like this 

ID     alternative123  val     pris    Menuvariation   quetime   

1          1            1        60           

1          2            0        75

1          3            0        0

1          1            0        90

1          2            1        120

1          3            0        0

2          1            0        75

2          2            1        60

2          3            0         0

2          1            1         0

2          2            0        120

2          3            0         75

3          1            0         0

3          2            0         75

3          3            1         90

3          1            1        120

3          2            0         90

3          3            0         0

 

Actually in a survey question we asked receipent to choose the alternative from group (1) A B C and from group(2) E F G. Every individual was too select an alternative from each group. The dependent variable val is their choice from both groups. If some one can guide me what is actually wrong with this command or some variable error can be.

 

Thanks in Advance

 

Akram 		 	   		  
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