Assuming that I precisely know which charity does how much good, I thought for a long time that it is most efficient to spend all my charity budget on this single charity. However, last week I thought that utility can be expressed as a function of how much money every charity has. So rather then spending everything on one charity, I should allocate my money based on the gradient of the utility function in it's current state (provided the utility function is smooth around this state). I would appreciate some (hopefully mathematically not challenging) comment.
Thanks.
Is there some value in dividing your donations among multiple organizations to lessen the risk that any one particular organization turns out to be less impactful than you thought? To me, it seems analogous to how investors divide their money among many companies to lessen the loss they'd suffer if any one company ended up losing money.
A related thought: if you have some level of moral uncertainty (e.g. about the value of human lives vs animal lives or lives saved vs lives improved), is donating to multiple charities together carrying out morally diverse interventions (e.g. animal welfare + global health; increasing consumption of the poor + saving lives) better? It seems like spreading out donations in this way would reduce the risk that you put all your money toward an intervention whose corresponding moral worldview turns out to you later to be less accurate than others.