I propose to use new terms: Importance, Implementability, Ignoredness. So three I's, with the I of Impact. 

Equation: 

Impact = Importance x Implementability x Ignoredness

In Dutch these are the three O's: Omvangrijk, Oplosbaar, Onderbelicht

the fact that mind is determined by a physical system not necessarily entail epiphenomenalism. My best analogy is the difference between the object language and the metalanguage. In mathematics (number theory, Godel's theorem), the metalanguage is embedded in the object language. https://en.wikipedia.org/wiki/Metalanguage#Embedded In this sense, the metalanguage supervenes on (and is determined by) the object language, but is not an epiphenomenon (and not eliminated either). 

What I meant was that from all public outreach, this deep questioning is one of the most cost-effective. If deep questioning is much less cost-effective than other strategies, then surely public outreach in general does not belong to the top effective strategies.

Which opportunity costs were not explored?

I think deep questioning should be done as an ancillary activity which people can do in their free time

Some grassroots animal rights organizations that do a lot of public outreach with volunteers, could perhaps switch to deep questioning, or encourage their volunteers to do so.

Please let me know how I could have earned extra money at those times when I do deep questioning ;-) I think it's really difficult, if you have some spare time today, to say: I'm going to earn some extra money. But I can imagine spending that spare time to learn some new skills and then use those acquired skill to switch career to a higher paying job. But to me, that's a difficult strategy. So to me, deep questioning public outreach seems to have a low opportunity cost.

That 0.6$ seems to me very low. The annual revenue of THL is almost $20M, so THL neutralizes the harm caused by 30 million people?

One conservative estimate of the effectiveness of deep questioning

-10% of people reduce meat consumption after the conversation

-for those reducers: 10% reduction of animal products (especially from the small animals)

-reduction fades out after 10 years.

So 10 conversations reduces the harm caused to farmed animals by the annual food consumption of a random person.

I did a small follow up study in my early days of deep questioning, around 2016. I mailed the people I spoke with on the street, a few months after our conversation. 50% responded to my mail, 20% of those respondents said they reduced their meat consumption since our conversation. That could mean 10% of people change their behavior. That seems pretty effective for the difference making risk averse person: it requires only 5 conversations with couples to make some difference. In my recent conversations, at the end of the conversation, roughly half of people say they really intend to reduce their meat consumption, try new meat alternatives. The other half is not interested that much. 

I often mention fish, eggs and shrimp, and especially mention that there is more suffering involved with smaller animals. I often mention that it is not good to replace chicken meat with eggs or fish.

Thanks for the questions, David. Insects are not really ignored. When I refer to small animals, that includes insects. The transition can happen in many ways, both legally (regulations that decrease chicken farming), economically (taxing chicken meat). Farmers can be asked to sell the land to the government, who turns it into grassland habitat. Social norms could be the major obstacle. Individual consumers can always resist social norms and decrease their consumption of products from small animals, even if that goes against the social norms. And we could of course change social norms. Also, there may be social norms about meat consumption in general, but not about chicken meat consumption. The ask is to reduce chicken meat consumption, which is more feasible than going vegan.  

thanks Vasco! Good comments. I added some things about people preferring a world with fewer higher welfare animals above a world with many more animals that have a higher probability of having a very negative welfare. Many people are risk averse, favor an asymmetric population axiology, favor avoiding suffering over creating happiness. 

I also added that we should do more research on wild animal welfare and turn the grassland into forests if research shows that animal welfare in forests is sufficiently higher. 

Wild animal welfare research and movement building is surely very good, but here I wanted to present something specific that people could actually choose to do right now, instead of "looking for what we could do in the future". 

Participants could see the title of the survey in their mail, before opening the survey. The participants get rewarded with a small value coupon when completing the survey, so I don't expect a pro-animal welfare selection bias. There was a question about active involvement level on animal welfare issues. Half of the respondents indicated to are not involved with animal welfare at all, 4% indicated high involvement, meaning e.g. eating no meat. Others had involvements like occasionally signing animal welfare petition. These statistics seem to be right, representative to the Belgian population. The survey was short, so not much difference between completion times. No significant differences in welfare range estimates were observed between people with more or less involvement, men or women,... Only relevant (statistically significant) difference: people with less active involvement had smaller negative estimates of broiler chicken welfare. I expect this to be a fluke, but again this indicates that the survey does not really have a pro animal welfare bias. Could be some social desirability bias, although I expect this to be small in anonymous online surveys of members of a marketing research company panel.

Good criticism, David. Although not entirely clear to me yet, especially the part in brackets. I'd say if we give up the assumptions of valence symmetry and scale linearity, matters are even worse for the chickens, because I expect most people to have a more negative skewed welfare scale (i.e. the negative side of the scale having a wider range than the positive side). If negative experiences can be 10 times as intense as positive experiences, a -3 welfare of a chicken would actually be a -30, i.e. 10 times larger in magnitude than a +3 welfare of a human. Also the answer options of the animal welfare range are skewed in favor of animals having a welfare range lower than 1. Hence, many aspects of the survey indicate that the suffering of broiler chickens is underestimated.

I don't think the revealed preferences of consumers are good indicators of people's estimates of the welfare levels of farmed animals, because of many reasons

1. Cognitive dissonance: see the meat paradox and the mind denial bias of meat eaters. Consumers simply don't think and don't want to think about the suffering of the animals they eat. Also, almost 10% of respondents say the survey makes them want to eat less meat. This is in line with personal experience I have with conversations with people on the streets. Just asking them whether they believe a chicken has a positive or negative welfare makes them more inclined to say they want to reduce their meat consumption.
2. The revealed preference is not only dependent on the estimated welfare level of an animal, but also on the moral weight one gives to animal welfare and other things unrelated to animal welfare. Perhaps a person beliefs that farmed animals suffer a lot, but doesn't consider animal suffering as important when it comes to food choices. Or the person believes that eating meat is necessary and one is allowed to eat meat at all cost, no matter how high the animal suffering is (comparable to the belief that Israel has an absolute right to self-defense and is allowed to defend itself against Hamas terrorism by attacking Gaza, no matter how high the cost to Palestinians).

I just conducted a survey (representative sample Belgian adult population), according to which most people believe the welfare range of a bird is equal to the welfare range of a human, and the welfare level of a broiler chicken is negative. https://forum.effectivealtruism.org/posts/MP4rNBu6ftG4QE3nL/the-suffering-of-a-farmed-animal-is-equal-in-size-to-the

Hence, Kyle's estimates of the welfare of farmed animals, based on Rethink Priorities median welfare range estimates, are underestimated according to most people (in Belgium). Most people would have to come to the conclusion that net global welfare is even more negative and more declining than what Kyle's calculation suggests.