Agricultural land redistribution is a type of agrarian reform in which large farms are broken up and distributed to tenants or landless peasants. Land redistribution typically requires exceptional circumstances to succeed. Past redistributive efforts have been most successful in the aftermath of revolution, war, or independence. When redistribution has succeeded, it has been accompanied by extensive agricultural support, such as rural infrastructure development, subsidies for fertilizers and high-yield seeds, agronomic training, and cheap credit. The main value of redistribution appears to be improved agricultural yields, but redistribution is neither a necessary nor sufficient condition for improved yields.

The value of charter cities can be divided into three main buckets: (1) direct benefits from providing an engine of growth that increase the incomes and wellbeing of people living in and around the city, (2) domestic indirect benefits from scaling up successful charter city policies across the host country, and (3) global indirect benefits from providing a laboratory to experiment with new policies, regulations, and governance structures. We think it is unlikely that charter cities will be more cost-effective than GiveWell top charities in terms of directly improving wellbeing.

Lead exposure is a large problem with social costs on the order of $5-10 trillion annually, most of which come through neurological damages and losses in IQ causing lost income later in life. Lead exposure is diverse both in terms of sources and geography, with there being many different pathways for environmental lead to enter the human body and exposure being common across nearly all low- and middle-income countries. Although the proportion of the lead burden attributable to different sources is unclear, important exposure pathways include informal recycling of lead acid batteries, residential use of lead-based paint, consumption of lead-adulterated foodstuffs, and cookware manufactured with scrap lead. Rough initial cost-effectiveness estimates suggest that some strategies for dealing with lead exposure could be as or more cost-effective than GiveWell top charities.

Are there differences in the characteristic intensity ranges of valenced experience across species? This question is important because the answer to it could affect the way we wish to spend our scarce resources helping different types of animals, including humans. For example, if the pains and pleasures of trout and salmon are but pale reflections of the pains and pleasures of cows and pigs, then in many instances we may be able to do more good helping mammals rather than fish.

Differences in the intensity range of valenced experience across species may affect how we ought to allocate resources to help different types of animals. Humans and other mammals likely share a roughly similar intensity range. It is unlikely that any species of animal possesses an intensity range that is exclusively extraordinarily mild. Some aspects of cognitive sophistication appear to be positively correlated with intensity range; other aspects of cognitive sophistication appear to be negatively correlated with intensity range. Affective complexity generally appears to be positively correlated with intensity range. There is as yet no good objective measure of valence intensity, though there is much interesting work ongoing in this area.

Considering differences in the subjective experience of time may affect the proportion of resources we wish to allocate to different species. I’ve recently written two pieces on the subject. Counting somewhat conservatively, the two posts total more than 23,000 words. In this (much shorter) post I attempt to succinctly introduce the topic and convey my main conclusions. The aim is to create a digestible overview of my current thinking that imposes a smaller time burden on readers.

The subjective experience of time is a morally significant aspect of well-being. Critical flicker-fusion frequency (CFF) has occasionally been suggested as a proxy for the subjective experience of time. CFF, a measure of visual temporal resolution, is the threshold at which a rapidly flickering light appears to glow steadily. CFF thresholds have been measured in more than 70 different species across 30+ orders and 3 phyla. Values range from ~7 Hz to ~200 Hz. Putatively similar animals sometimes possess very different CFF thresholds. I tentatively estimate there is a ~40% chance that CFF values roughly track the subjective experience of time under ideal conditions.

The subjective experience of time refers to how slow or fast time appears to pass for an individual. Animals with faster rates of subjective experience undergo more subjective moments per objective unit of time than animals with slower rates of subjective experience. Roughly speaking, animals with faster rates of subjective experience perceive the world as if it were slowed down compared to the perceptions of animals with slower rates of subjective experience. Based on human reports of alterations in the subjective experience of time, as well as general differences in behavior, neurology, and temporal resolution across animals, I estimate there is a ~70% chance that there exist morally relevant differences in the subjective experience of time across species.

An animal’s capacity for welfare is how good or bad its life can go. An animal’s moral status is the degree to which an animal’s experiences or interests matter morally. It’s plausible that animals differ in their capacity for welfare and/or their moral status. These differences could affect the way we ought to allocate resources across interventions and/or cause areas. Unfortunately, measuring capacity for welfare and moral status is tremendously difficult. When donors or researchers choose to focus on cause areas or interventions that target certain species rather than others, they are often implicitly making judgments about the comparative value of different animals (including humans). Without a model for quantifying differences in comparative value, such judgments are apt to be guided by imperfect and likely unreliable heuristics.

Understanding differences in capacity for welfare and moral status could significantly affect the way we wish to allocate resources among interventions and cause areas. For instance, some groups of animals that exhibit tremendous diversity, such as fish or insects, are often treated as if all members of the group have the same moral status and capacity for welfare. Further investigation could compel us to prioritize some of the species in these groups over others. More generally, if further investigation suggested we have been overestimating the moral value of mammals or vertebrates compared to the rest of the animal kingdom, we might be compelled to redirect many resources to invertebrates or non-mammal vertebrates. To understand the importance of these considerations, we must first develop a broad conceptual framework for thinking about this issue.

Ballot initiatives are a form of direct democracy in which citizens can gather signatures to qualify a proposed piece of legislation for the ballot, which is then subject to a binding up-or-down vote by the general electorate. Ballot initiatives are possible in Switzerland, Taiwan, many U.S. states and cities, and elsewhere. Ballot initiatives appear to maintain several advantages over more traditional policy lobbying, including lower barriers to entry and more direct control over the final legislation. However, the ultimate cost-effectiveness of a ballot initiative campaign depends on several factors, many of which are difficult to specify precisely. Although ballot initiatives hold enough promise to warrant additional investigation, it is not yet possible to say to what extent ballot initiative campaigns ought to be pursued by the effective altruism community.

At any given time there are more than a trillion managed honey bees. Globally, the number of managed colonies has risen steadily over the last twenty years and this growth will almost certainly persist, at least in the short term. Increases in demand for honey and (especially) commercial pollination services continue to outpace the increase in supply of managed bees. Asia, especially China and India, hosts the largest populations of managed bees and accounts for much of the recent growth in bee stocks. Commercial beekeeping techniques standardly treat managed bees as a resource from which to maximize the extraction of value. Beekeepers have a financial incentive to maintain the health of their colonies, but they have little reason to look after the welfare of individual bees. Managed bees suffer from a variety of problems, including pesticide exposure, poor nutrition due to inadequate access to natural forage, invasive hive inspections and honey harvest, stress from long-distance transport, and parasite and pathogen spread exacerbated by common management techniques.

In this post, four members of Rethink Priorities’ invertebrates team—Daniela R. Waldhorn, Marcus A. Davis, Peter Hurford, and Jason Schukraft—outline their views on the value, feasibility, and danger of quantitative estimates of invertebrate sentience. Marcus and Peter provide numerical estimates of sentience for each of the taxa we investigated for our invertebrate sentience project, Daniela offers a qualitative ranking of the same taxa, and Jason argues that we are not yet in a position to deliver estimates that are actionable and robust enough to outweigh the (slight but non-negligible) harm that publishing such estimates prematurely might engender.

More than 99.9% of animals are invertebrates. There is modest evidence that some large groups of invertebrates, especially cephalopods and arthropods, are sentient. The effective animal activism community currently allocates less than 1% of total spending to invertebrate welfare. That share should rise so that we can better understand invertebrate sentience and investigate the tractability of improving invertebrate welfare.

In this, the final of three posts on features potentially relevant to invertebrate sentience, we assess 9 learning indicators, 4 navigational skills, and 7 mood state behaviors.

In this, the second of three posts on features potentially relevant to invertebrate sentience, we assess 5 drug responses, 5 motivational tradeoffs, and 5 feats of cognitive sophistication.

In this, the first of three posts on features potentially relevant to invertebrate sentience, we assess 10 anatomical and evolutionary features and 5 types of noxious stimuli reactions.

Rethink Priorities reviewed the scientific literature relevant to invertebrate sentience. We selected 53 features potentially indicative of the capacity for valenced experience and examined the degree to which these features are found throughout 18 representative biological taxa. These data have been compiled into an easily sortable database that will enable animal welfare organizations to better gauge the probability that (various species of) invertebrates have the capacity for valenced experience. This essay details what we’ve done, why, and the strengths and weaknesses of our approach.

Other humans merit moral concern. We think many nonhumans merit moral concern too. But how do we know? And which nonhumans? Chimpanzees? Chickens? Bumblebees? Protozoa? Roombas? Rocks? Where and how do we draw a line?