On moral value as a linear function of well-being and comparability of SWB measures across different income settings
As you allude to, there are two issues here. If I think person A going from 0⁄10 to 1⁄10 life satisfaction has greater moral value than B going from 9⁄10 to 10⁄10, that might be because (1) you think each has the same increase in well-being, but you want to give extra weight to the worse off. This is the prioritarian point you say you are not making.
The alternative, (2) is that you think A really has had a bigger increase in well-being than B even though both have reported a 1-unit change in life satisfaction. (2) raises a concern about whether the subjective scales are cardinally comparable. This isn’t a moral problem, so much as a scientific one of measurement. Technically, the issue is whether numerical scores from subjective self-reports are cardinally comparable. I’ve got a working paper on this topic (not public apart from this link) where I delve into this and conclude subjective scales are likely cardinally comparable. The basic issue here, I think, is about how people are use language when interpreting survey questions; not much seems to have been written about it. With regards to your point about “comparability of SWB measures across different income settings” the document I linked to provides a rationale for why I suspect they are comparable.
On moral value as a linear function of well-being and comparability of SWB measures across different income settings
As you allude to, there are two issues here. If I think person A going from 0⁄10 to 1⁄10 life satisfaction has greater moral value than B going from 9⁄10 to 10⁄10, that might be because (1) you think each has the same increase in well-being, but you want to give extra weight to the worse off. This is the prioritarian point you say you are not making.
The alternative, (2) is that you think A really has had a bigger increase in well-being than B even though both have reported a 1-unit change in life satisfaction. (2) raises a concern about whether the subjective scales are cardinally comparable. This isn’t a moral problem, so much as a scientific one of measurement. Technically, the issue is whether numerical scores from subjective self-reports are cardinally comparable. I’ve got a working paper on this topic (not public apart from this link) where I delve into this and conclude subjective scales are likely cardinally comparable. The basic issue here, I think, is about how people are use language when interpreting survey questions; not much seems to have been written about it. With regards to your point about “comparability of SWB measures across different income settings” the document I linked to provides a rationale for why I suspect they are comparable.
This is a great summary of what I was and wasn’t saying :)
Thanks for the link—looking forward to reading. Might return to this after reading