Hey everyone,

I am new to stata and CE and I hope some one can help me how to include opt-out options in my choice experiment.

I created a Choice Set (16x2 resulting in 32 options) with an Opt-Out Option and now I am struggling with including this opt out option in my data and my mixed logit model.
I found a comment of Arne Hole in a discussion forum:

If you code the variables as missing for the opt-out alternative you will effectively remove this alternative from the choice set. Another option is to code the variables as zeroes and include an alternative-specific constant for the opt-out alternative.

I coded the opt out options as 0. For the alternative specific constant (ASC), I found literature which say that they include this constant and code it as ASC=1 if its Option A or B and ASC=0 if its the opt out option.

Unfortunately, I don't know how to further proceed.

Would that mean for me that I would simply add another column "ASC" to my dataset in the Excel file and add the corresponding encoding (1 or 0)? Would I then have to change something in my code in the do file accordingly, for example simply enumerate ASC with the other attributes in the code?

Thank you
Charlotte