I couldn't find Uni-dimensional scales to measure ethical consumption in luxury fashion brands. Kindly recommend or suggest any reference having such items or scales.
There is none that I know currently in terms of consumption since is attitudinal and behavioral which cannot be measured because is not static. Individuals change their attitudes for different reasons. Different authors give different dimensions for ethical consumption for luxury fashion. You can check Henniger et al (2017; 2016) for more on luxury fashion. Colon (2019) on ethical brand.
I am not saying it does not exist but I am saying from consumer behaviour point of view it is not unidimensional. As ethical consumption involves saving water and energy, less washing, prolonged use of luxury fashion items, use of non toxic chemicals or detergent for laundry, recycle, downcycle or upcycle to create newer versions, use as classic wear etcetera. Therefore it cannot be unidimensional.