Rethink Priorities hosted the “Dimensions of Pain” workshop in April 2023 with experts in pain research. The goal was to identify empirical methods to test whether brief but severe pains (e.g. botched slaughter) or milder but longer pains (e.g. lameness) have a greater overall negative impact on farmed animals' welfare. This report summarizes the results and our researchers' updated conclusions.

This is the fifth post in the Moral Weight Project Sequence, which provides an overview of the research Rethink Priorities conducted between May 2021 and October 2022 on making resource allocation decisions across species. This post assesses the hypothesis that brains have many conscious subsystems, which could affect how we ought to make tradeoffs between members of different species.

This is the fourth post 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 summarize our full report on the use of neuron counts as proxies for moral weights.

This report is a postscript to "The relative Importance of the severity and duration of pain,” and addresses whether the order of negative and positive experiences matter. For example, is pain worse if it occurs at the end of an individual’s life?

How should effective altruists decide whether to prioritize interventions that alleviate severe but relatively brief suffering or instead those that alleviate longer-lasting but less severe suffering? When one pain is longer-lasting but less intense than a second pain, the most straightforward way to compare how much disutility they cause is to multiply how much longer by how much less severe the first pain is than the second pain. This report investigates whether this mathematical approach is sufficient for making cause prioritization decisions, requires some amendments, or is fundamentally flawed.