Imagine that I can donate to save a life today for $4000. And imagine that I can invest that $4000 and earn 2% (for example) above the rate of inflation. Then in 35 years, I would have $8000, and could save two lives. If those future lives are worth the same as the life today, then of course I should never save a life today, but invest to save twice as many lives 35 years from now. But by the same logic, I shouldn’t save lives then, but keep investing. This leads to the absurd conclusion that I should never donate to save lives, as I could always do more good in the future.
The logical conclusion is that I should discount future good I might do by at least the real rate of investment return. I should value saving a life today twice as much as saving a life in 35 years, assuming my 2% figure.
The logic here seems off. Suppose we discover a new unusually profitable investment that gets you a real rate of return of >100%[1]. Will you suddenly update towards believing that saving a life next year is only half as valuable as saving a life today? More broadly, it seems suspicious that you should peg your (moral) discount rate to be always greater than (empirical) rates of returns, regardless of the facts on the ground. Like surely at some level of investment returns donating later is more valuable than donating now?
The logic here seems off. Suppose we discover a new unusually profitable investment that gets you a real rate of return of >100%[1]. Will you suddenly update towards believing that saving a life next year is only half as valuable as saving a life today? More broadly, it seems suspicious that you should peg your (moral) discount rate to be always greater than (empirical) rates of returns, regardless of the facts on the ground. Like surely at some level of investment returns donating later is more valuable than donating now?
Which is plausible for some human capital interventions, for example getting training for job negotiations.