As you say, there is an issue that some of these things might really be enhancements because they aren’t of a fixed size. This is especially true for those that have instrumental effects on the wellbeing of individuals, as if those effects increase with total population or with the wellbeing level of those individuals, then they can be enhancements. So cases where there is a clearly fixed effect per person and a clearly fixed number of people who benefit would be good candidates.
As are cases where the thing is of intrinsic non-welfarist value. Though there is also an issue that I don’t know how intrinsic value of art, environmental preservation, species types existing, or knowledge is supposed to interact with time. Is it twice as good to have a masterpiece or landscape or species or piece of knowledge for twice as long? It plausibly is. So at least on accounts of value where things scale like that, there is the possibility of acting like a gain.
Another issue is if the effects don’t truly scale with the duration of our future. For example, on the longest futures that seem possible (lasting far beyond the lifetime of the Sun), even a well preserved site may have faded long before our end point. So many candidates might act like gains on some durations of our future, but not others.
As you say, there is an issue that some of these things might really be enhancements because they aren’t of a fixed size. This is especially true for those that have instrumental effects on the wellbeing of individuals, as if those effects increase with total population or with the wellbeing level of those individuals, then they can be enhancements. So cases where there is a clearly fixed effect per person and a clearly fixed number of people who benefit would be good candidates.
As are cases where the thing is of intrinsic non-welfarist value. Though there is also an issue that I don’t know how intrinsic value of art, environmental preservation, species types existing, or knowledge is supposed to interact with time. Is it twice as good to have a masterpiece or landscape or species or piece of knowledge for twice as long? It plausibly is. So at least on accounts of value where things scale like that, there is the possibility of acting like a gain.
Another issue is if the effects don’t truly scale with the duration of our future. For example, on the longest futures that seem possible (lasting far beyond the lifetime of the Sun), even a well preserved site may have faded long before our end point. So many candidates might act like gains on some durations of our future, but not others.