Animals currently make up the vast majority of sentient beings. As many as 2.8 trillion animals might be killed for food each year, and there are many more animals in the wild (Reese 2016). Although many experts agree that animals display some signs of sentience, it remains an open question which animals are sentient, and how we should compare welfare between species. Nevertheless, the welfare of animals is potentially a hugely important issue.
Despite its importance, this focus area is highly neglected: animal charities receive only 3% of charitable donations, and 99% of that money is focused on pets, who make up less than 0.1% of all domesticated animals (Reese 2016).
The area also appears to be somewhat tractable. Animal Charity Evaluators estimates that leafleting campaigns can spare about three years of suffering in factory farms per dollar donated (Animal Charity Evaluators 2016), while the Open Philanthropy Project, in turn, estimates that past corporate cage-free campaigns have spared about 120 years of suffering in battery cages per dollar donated (Bollard 2016).
Some have argued that, if one takes the view that future beings matter morally, interventions that seek to reduce short-term animal suffering may not be as cost-effective as interventions that seek to influence the far future. In response, others have argued that animal welfare will also have strong beneficial effects on the far future (Reese 2016). An objection to that argument is that it would be remarkable if an intervention selected for its short-term effects just happened to have better long-run consequences than all other interventions (Lewis 2016). In addition, critics have noted that there are theoretical reasons for expecting human interventions to have better long-run effects than animal interventions (Cotton-Barratt 2014). The considerations bearing on this issue are numerous, complex, and hard to assess, and the debate is currently unresolved (Tomasik 2016).
Centre for Effective Altruism. Cause profile: Animal welfare
Animal Charity Evaluators. 2016. Impact calculator. An interactive app that calculates the impact of leafleting and online ads on animal welfare, given various assumptions.
Bollard, Lewis. 2016. Initial grants to support corporate cage-free reforms. A report estimating the cost-effectiveness of corporate cage-free reforms.
Cotton-Barratt, Owen. 2014. Human and animal interventions: the long-term view. A blog post outlining some considerations for thinking that human interventions are more effective than animal interventions.
Lewis, Gregory. 2016. Beware suspicious and surprising convergence. A blog post arguing that we should be skeptical of arguments concluding that some intervention best attains some goal, when this intervention was chosen because it was perceived to be optimal in attaining a different, unrelated goal.
Reese, Jacy. 2016. Why animals matter for effective altruism. An essay making the case for animal welfare as a top focus area of the effective altruism community.
Tomasik, Brian. 2016. Risks of astronomical future suffering. A discussion of the long-run future, with some discussion of animal issues.