*
* Example from section 16.4.3, page 433
*
open data cola.dat
data(format=free,org=columns) 1 5466 id choice price feature display
*
* Define a variable which shows which drink this row describes. (%clock(n,m) is a
* modulo operator that maps to 1,...,m rather than 0,...,m-1)
*
set drink   = %clock(t,3)
*
* Define dummies for Pepsi and SevenUp.
*
set pepsi   = drink==1
set sevenup = drink==2
*
ddv(type=conditional,indiv=id,mode=drink) choice
# price pepsi sevenup
*
* These are the three scenarios examined for predicting probabilities. The base
* has the original settings of $1 for Pepsi, $1.25 for SevenUp and $1.10 for Coke.
* You have to make sure that you set the correct values for the two dummy
* variables.
*
dec rect base(3,3)
input base
 1.00 1 0
 1.25 0 1
 1.10 0 0
*
* Same as base except for the price on Pepsi (the (1,1) element).
*
dec rect case1(3,3)
input case1
 1.10 1 0
 1.25 0 1
 1.10 0 0
*
* Same as base except for the price on Coke (the (3,1) element).
*
dec rect case2(3,3)
input case2
 1.00 1 0
 1.25 0 1
 1.15 0 0
*
@PRJConditional(title="Base Probabilities",attrib=base,labels=||"Pepsi","SevenUp","Coke"||)
@PRJConditional(title="With Higher Pepsi",attrib=case1,labels=||"Pepsi","SevenUp","Coke"||)
@PRJConditional(title="With Higher Coke",attrib=case2,labels=||"Pepsi","SevenUp","Coke"||)