Moral weights

QALYs, DALYs, and WELLBYs help you compare interventions that produce the same type of outcome—different ways to avert deaths, for instance. But what about comparing across outcome types? How do you weigh preventing a child’s death against doubling a family’s income for a year? Or reducing chronic pain against curing blindness?

GiveWell handles this through moral weights—units of value assigned to different outcomes so they can be placed on the same scale. Their current framework uses three outcome types: mortality (preventing deaths), morbidity (reducing suffering from illness or disability), and consumption (increasing people’s ability to buy what they need). As a baseline, they assign a value of 1 to doubling one person’s consumption for one year, and a value of roughly 100 to averting a death.

These numbers aren’t derived from a formula. They’re informed by surveys, philosophical reasoning, and judgement—and they have real consequences. The ratio between “averting a death” and “doubling income” determines whether GiveWell recommends health charities or cash transfer programmes. Small changes in moral weights can flip an entire ranking.

This is worth sitting with. The decision about how much a life is “worth” relative to an increase in income isn’t a technical question—it’s a moral one. And GiveWell is making that decision on behalf of hundreds of millions of dollars in donations. They’re transparent about it, which is admirable. But transparency doesn’t resolve the underlying difficulty.

Read: GiveWell, “Apples, oranges, and outcomes” (10 mins) https://blog.givewell.org/2025/07/17/apples-oranges-and-outcomes/