Thanks – I appreciate it! As I said before, the draft is very much work in progress so I'm sure these comments will be useful. 

Great work – this looks really useful! 

Minor comment: A few years ago, I looked into estimates of the ratio of animal lives lost to a kilogram of animal protein. One of the facts that were really striking to me was how much the ratio has changed over time in the US for many animal protein products (e.g., dairy cows produce significantly more milk now than they used to). Given how much the ratio has changed over time, it seems likely that there is also a fair bit of heterogeneity between countries. For the OWID charts that display "Animal lives lost per kilogram of product", "Animal lives lost per kilogram of product, including indirect deaths", and "Kilograms of meat produced per animal", it might therefore be worth adding one more sentence in the description clarifying whether the estimates are for the US, the world, or something else. One could of course find this information by clicking on the source, but it may not occur to everyone that the ratios may differ between countries.

Thanks again for posting this!

Thanks for this writeup – I imagine that it will be very helpful to some other EA groups! When I was the president of EA Stockholm University we organised something similar in several welcome fairs at Stockholm University. Some experiences from this:

1. The most important thing that I learned was that it is very useful to have some introductory event planned in the next week or even next few days after the fair, so that one can encourage people to attend that event.
2. For the giving game we used real money, which was laying openly on the table where we were standing. I think this attracted more people to the table than we otherwise would have gotten, so I agree with you that doing this when possible is probably a good idea. If I remember correctly, we had 3000 SEK in 100-bills. Once 30 people had participated, we counted the money in each bucket and then took it out so that the same bills could be used once again. At the end of the game we summed up everything and donated it. Usually we only had something like 50 participants, so it amounted to donating roughly 5000 SEK in total.
3. For one fair we had charities from different cause areas (global development, animal welfare and something else that I can't remember) instead of charities within a cause area. This allows for more discussion about cause selection, but probably invites people to think less critically (i.e., just pick what feels like a good cause to them). 
4. We tried doing speed giving games at some welcome fairs and not doing it at others. Our experience was that doing speed giving games helped attract people to the table, but made it somewhat harder to engage in depth as a lot of the focus of the conversation often revolved around explaining the rules of the giving game as opposed to explaining what EA is and how to get involved. When I was at EA SU, we eventually decided to not do speed giving games at welcome fairs for this reason, but I think we were uncertain whether this was the right decision and it probably depends a lot on the particulars of the welcome fair in question etc.

Again, thanks for writing this up!

Thanks – this is a very important point and I am glad that you raised it! Overall, I think we should be very uncertain about what the long-run population dynamics might be after a catastrophe. I am not sure how much we disagree, but I tried to add some thoughts below (Note: Maya might not necessarily agree with my thoughts on this issue).

As you point out, we write in the paper that Malthusian population dynamics may reemerge in the long run and that evolutionary pressures are one of the main reasons to expect that this might happen. We do not directly argue that such reemergence won’t happen, but in the footnote that follows immediately after that passage you quoted we write:

"In contrast, Arenberg et al. (forthcoming) argue that “empirical facts and models of heritability do not provide reason to conclude that positive population growth is bound to continue via the dynamics of a higher-fertility type making up an ever-increasing share of the global population”.

Here's an attempt to quickly explain Arenberg et al.’s argument: Arenberg et al. point out that we “should not conflate higher fertility within a heterogeneous population with high or above-replacement fertility: it is an empirical question whether future higher-fertility sub-populations will have above replacement fertility”. They then argue that “there is strong historical and global evidence that even higher-fertility groups will eventually trend to near or below replacement fertility”. Drawing on these insights, they introduce a model indicating that “long-term population growth can be negative even with both strong heritability and an above-replacement-fertility sub-population”.

Now, it could reasonably be argued that evolutionary pressures will nonetheless determine fertility rates on 100,000+ year timeframes. However, even if this is correct, such timeframes are only relevant if there is at least a decent probability that humanity will still be around in 100,000 years (conditional on surviving this century). This is not obvious; for instance, if the background probability of human extinction is 1% in each century, then the probability that humanity is still around after 100,000 years is only 0.004%. It is therefore not clear to me that the Malthusian model is correct, so it seems sensible to take other models of fertility seriously.

Thanks again for engaging with the paper!

I just want to second the point that some others have made that it seems more accurate to say only that Harsanyi's result supports utilitarianism (rather than total utilitarianism). Adding the word "total" suggests that the result rules out other version of utilitarianism (e.g. average, critical-level and critical-range utilitarianism), which as you point out is not correct. More generally, I think "utilitarianism" (without the "total") nicely signals that Harsanyi's result concerns fixed-population settings.

It is also worth noting that Harsanyi himself accepted average utilitarianism rather than total utilitarianism in variable-population settings (see the letter exchange between him and Yew-Kwang Ng reported in the appendix of Ng, Y. K. (1983). Some broader issues of social choice. In Contributions to Economic Analysis  (Vol. 145, pp. 151-173). Elsevier.).

Anyway, thanks for this post!

[Edited comment to remove grammatical error]