Elsewhere in his article, Parfit discusses probability discounting, which Parfit demonstrates does not always correlate with time-based discounting. I think probability discounting is closer to the intuition you have regarding the irrelevance of Cleopatra’s spending on dessert vs whether cures for cancer exist now.
Parfit’s example involving Cleopatra is meant to show that, for example, spending on Cleopatra’s dessert would be ranked by a policy-maker of her government as having higher value than spending whose higher value (curing cancer) would not accrue until presumably thousand’s of years later, if the policymaker used temporal discounting to make the comparison .
Your line of argument against longtermism, that today’s actions have increasingly uncertain far-future outcomes, might coincide with the belief that probability discounting is a good thing even though time-based discounting is, as Parfit claims, nonsense. However, I see a dilemma in that, assuming that Cleopatra’s government expected her empire to continue indefinitely, its policymakers could allocate money during Cleopatra’s time toward identifying and curing human disease over the long-term. It would be a reasonable expectation on the policymakers’ part that the empire’s chances of discovering cures for cancer would go up, not down, over a few thousand years.
Agreed, “probability discounting” is the most accurate term for this. Also, I struck out the part about Cleopatra in the original post, now that I understand the point behind it!
Interesting write-up, thanks!
Elsewhere in his article, Parfit discusses probability discounting, which Parfit demonstrates does not always correlate with time-based discounting. I think probability discounting is closer to the intuition you have regarding the irrelevance of Cleopatra’s spending on dessert vs whether cures for cancer exist now.
Parfit’s example involving Cleopatra is meant to show that, for example, spending on Cleopatra’s dessert would be ranked by a policy-maker of her government as having higher value than spending whose higher value (curing cancer) would not accrue until presumably thousand’s of years later, if the policymaker used temporal discounting to make the comparison .
Your line of argument against longtermism, that today’s actions have increasingly uncertain far-future outcomes, might coincide with the belief that probability discounting is a good thing even though time-based discounting is, as Parfit claims, nonsense. However, I see a dilemma in that, assuming that Cleopatra’s government expected her empire to continue indefinitely, its policymakers could allocate money during Cleopatra’s time toward identifying and curing human disease over the long-term. It would be a reasonable expectation on the policymakers’ part that the empire’s chances of discovering cures for cancer would go up, not down, over a few thousand years.
Agreed, “probability discounting” is the most accurate term for this. Also, I struck out the part about Cleopatra in the original post, now that I understand the point behind it!