I’m not sure if the arguments for diversification in investments actually apply to charity. You want to diversify your investments because you’re risk averse. I would not, for example, bet $1000 on a coin flip; losing $1000 is more painful to me than gaining $1000 is pleasurable. In other words, your utility is not linear in money in your bank account.
However, for charity, I think it makes perfect sense to have linear utility in money donated to charity. If you value saving two lives twice as much as saving one, and the cost per life saved is constant, then you should value each dollar given to charity as much as the last. Given that, you shouldn’t really care about variance; you can focus on expected returns. As such, I don’t think you should diversify charity donations at any scale, personal or on a worldwide scale; just donate to the most efficient charity, and then when that charity becomes less efficient, donate to the newest most efficient.
I’m not sure if the arguments for diversification in investments actually apply to charity. You want to diversify your investments because you’re risk averse. I would not, for example, bet $1000 on a coin flip; losing $1000 is more painful to me than gaining $1000 is pleasurable. In other words, your utility is not linear in money in your bank account.
However, for charity, I think it makes perfect sense to have linear utility in money donated to charity. If you value saving two lives twice as much as saving one, and the cost per life saved is constant, then you should value each dollar given to charity as much as the last. Given that, you shouldn’t really care about variance; you can focus on expected returns. As such, I don’t think you should diversify charity donations at any scale, personal or on a worldwide scale; just donate to the most efficient charity, and then when that charity becomes less efficient, donate to the newest most efficient.