We are working on an ACBC study and have a few attributes with 1 level. The way we got around this was having spaces to 'trick' sawtooth into thinking that they were different. For example:
3. Free (space space)
We have completed the fieldwork and are in the process of calculating utility estimations. My question is what can we do with these attributes with different levels which are actually the same? I think in another forum post the suggestion was to exclude the attribute from the alternative specific design, but this is not possible for us because one of these attributes is a primary one!