Given an intervention of value v, you should be willing to pay for it if the cost c satisfies c≤v (with indifference at equality).
If your budget constraint is binding, then you allocate it across causes so as to maximize utility.
Given an intervention of value v, you should be willing to pay for it if the cost c satisfies c≤v (with indifference at equality).
If your budget constraint is binding, then you allocate it across causes so as to maximize utility.