Hi all! I'm working on a choice experiment with two unlabelled alternatives and 6 attributes (one with 4 levels, and five with 3 levels). One of the attributes is 'price'.

I'll use the betas for two models afterwards: one that will include the 'price' beta, and another one that won't include the 'price' beta.

I, therefore, need a design that allows me to estimate the betas in both situations (one with 'price' and another without it).

To do so, I am using Stata to create a candidate set that includes overlapping in the "price" attribute.

My question has to do with the creation of the candidate set. I have already the full factorial (944,784 pairs). Should the candidate set include all choice sets overlapping in the "price" attribute, plus 1,000 or 2,000 randomly selected?

I think what I need is to guarantee a minimum number of choice tasks with the overlapping in "price", so as to be able to estimate betas for both models/situations (one with the 'price' beta, and another one without it). I hope the question is not too weird.

I'd appreciate any guidance on this!

Best wishes,

Pamela