EA - An Introduction to the Moral Weight Project by Bob Fischer

Link to original articleWelcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: An Introduction to the Moral Weight Project, published by Bob Fischer on October 31, 2022 on The Effective Altruism Forum.Key TakeawaysOur objective: provide “moral weights” for 11 farmed species.To make this tractable, we made four assumptions: utilitarianism, hedonism, valence symmetry, and unitarianism.Given these assumptions, an animal’s “moral weight” is that animal’s capacity for welfare—the total amount of welfare that the animal could realize.Capacity for welfare = welfare range (the difference between the best and worst welfare states the individual can realize at a time) × lifespan.Given welfare ranges, we can convert welfare improvements into DALY-equivalents averted, making cross-species cost-effectiveness analyses possible.An Introduction to the Moral Weight ProjectIf we want to do as much good as possible, we have to compare all the ways of doing good—including ways that involve helping members of different species. But do benefits to humans count the same as benefits to chickens? What about chickens vs. carp? Carp vs. honey bees? In 2020, Rethink Priorities published the Moral Weight Series—a collection of five reports about these and related questions. The first introduces different theories of welfare and moral status and their interrelationships. The second compares two ways of estimating differences in capacity for welfare and moral status. The third explores the rate of subjective experience, its importance, and potential variation in the rate of subjective experience across taxa. The fourth considers critical flicker-fusion frequency as a proxy for the rate of subjective experience. The fifth assesses whether there’s variation in the intensity ranges of valenced experiences from species to species.In May 2021, Rethink Priorities launched the Moral Weight Project, which extended and implemented the research program that those initial reports discussed. This post is the first in the Moral Weight Project Sequence. The aim of the sequence is to provide an overview of the research that Rethink Priorities conducted between May 2021 and October 2022 on interspecific cause prioritization—i.e., making resource allocation decisions across species. The aim of this post is to introduce the project and explain how EAs could use its results.DALYs-averted and “moral weight discounts”If we want to do the most good per dollar spent—that is, if we want to maximize cost-effectiveness—we need a common currency for comparing very different interventions. GiveWell, Founders Pledge, Open Philanthropy, and many other EA organizations currently have one: namely, the number of “disability-adjusted life years (DALYs) averted.” A DALY is a health measure with two parts: years of human life lost and years of human life lost to disability. The former measures the extent to which a condition shortens a human’s life; the latter measures the health impact of living with a condition in terms of years of life lost. Together, these values represent the overall burden of the condition. So, averting a DALY is averting a loss—namely, the loss of a single year of human life that’s lived at full health.Historically, some EAs used a “moral weight discount” to convert changes in animals’ welfare levels directly into DALYs-averted. That is, they understood the basic question to be:At what point should we be indifferent between (say) improving chickens’ welfare and preventing the loss of a year of healthy human life?Then, the task is to identify the correct “moral weight discount rate” to apply to the value of some quantity of chicken welfare to make it equal to the value of averting a DALY.This framing makes it tempting to think in terms of the value that (certain groups of) people assign to chicken welfare (or the welfare of the members of whatever species) relative to the ...