It only asked me for my name (not citizenship, residency, or address), so not sure if they cross check with a citizens directory or something, but the UK didn't require citizenship to answer a public consultation on the kinds of causes their international aid should go towards so it seems like they just allow anyone to give input. 

Done, thanks for posting this! Concrete ways to take action in a high-impact, low-input way are really nice to see on the forum!

Just sent a letter. This post was what pushed me to do it-- I am a CA voter and have never written a letter urging the governor to take action on legislation before, and I believe I wouldn't have done so without 1. reading this post and 2. reading Will MacAskill's comment on this post. So that's counterfactual impact on your part, nice one!

I'd love to see this with select US states (like California) included as their own bars. This is super interesting, thanks for making it!

Nice, just donated my $31.23 worth of Mana to GiveWell! Wouldn't have known to do that otherwise, and took about 30 seconds. Thanks for the post :)

This is very exciting! Can't wait to CE's successful formula applied to new high-impact areas & programs.

Big +1 to making weighted factor model spreadsheets for decisions! They're soooo good (for small decisions too). Plus, once you've made one, you can reuse the template :) All great advice Alexandra, thanks for writing this up!

Great idea! This could be a great way to think of gift ideas and get more people to donate around holidays/special events. I wonder if there's room to expand/proliferate projects like this...

I'm so sorry to hear this news. I'm glad that this community can be a place of remembrance and to honor Sebastian's commitment to impact and giving. I especially wish strength and peace for Sebastian's family. 

Very interesting write-up, thank you for it.

As pointed out in an earlier comment, raising the compensation for challenge trials and/or seeking out participants with lower 'willing participation price' seems promising as a way to get enough participants.

I would be interested to see an analysis on the "donation equivalent" of participation.

E.G. if it would cost 10k to pay a willing participant, and an EA were willing to do it for free for social good, is this the "equivalent" of a 10k donation to an effective health cause? If not, approximately how much would it be worth? Putting a number on this would be interesting, and could help individuals decide whether to participate (comparing to their opportunity costs, etc).

Heck, maybe if we had a number, individuals who track donations could even log challenge participation as a number amount towards their donation goal (e.g. for those who donate 10% of their incomes), though that's probably a whole different conversation.