Willingness to Accept and price variable in relative terms

[Insa]

Hello,
Some time ago I conducted a Discrete Choice Expermiment among farmers about their willingness to use an emission reduction technology.
At that time, we decided to use a cost share in % as a price variable, as the costs of the examined procedure could not be clearly quantified (hypothetical market).

The attributes in the choice sets are emission reduction in %, cost share in %, reliefs on the German fertilizer ordinance (dummies).

A colleague of mine raised the question of whether the Willingness to Accept can be calculated at all with a price variable in percentage points (cost share offered).I assumed at the time that it was possible, since it only describes the relationship between two marginal effects. Nevertheless, I would like to clarify this and I would be glad if you could help me, since I could not find anything in the literature.
Regards Insa

[Michiel Bliemer]

If you use price in $ (or another currency) as an attribute then you can compute the WTA in terms of the amount of money. If you use a price deviation in percentage then I think you are computinh the WTA in terms of the percentage of cost sharing, so it is not expressed in the amount of money but rather a percentage. If that is what you are looking for, then it is fine. If you need WTA expressed in money, then you probably need to assume a base level in S and convert the percentages into amount of money. But this may only be possible if the respondents were aware of this base level.

Michiel

[Insa]

Thank you very much, this helps a lot!