For one item in my ACBC I used a constructed list so that only 6 of the 18 items are included in the conjoint analysis. When I check the results it shows that also the items that weren’t included in the analysis show very utility scores.
I used the recommended “Inferior to Included Levels” option for HB estimation for levels that have not been included. I checked the results and it seems that one attribute level has an average utility of 132,30 even though no one chose that level to be part of the survey, so it wasn't included in the ACBC. It has the highest utility score of all levels.
It doesn’t really make sense to me that an attribute level that no one chose to be part of the survey has such a high utility.
I also used the setting “Unavailable (Zero Probability of Choice)” with a low part-worth utility of -10. If I do so, the same attribute level has a utility of -53,78.
Do you have any explanation how that is possible?