This is a good point. I may be misinterpreting the cited research, but if the proposed training increases disclosures of CSA, that will (a) presumably reduce 'costs as a consequence' (which includes a monetised value of the physical and emotional harm suffered) but (b) plausibly increase 'costs in response' (due to increased police, prison, and safeguarding costs)

Considering that immigrants are also cheaper to the state than the native-born, and they outearn the native-born, migrants who arrived 2019-2023 will make a net contribution to British finances.

I do not think that the UK should restrict immigration for fiscal reasons. If the UK does choose to restrict immigration - as it seems inclined to do - it should be clear about why. It is not because immigrants have placed “public services and housing access… under too much pressure” and immigration threatens the welfare state. Rather, it is simply because voters don’t like it very much.

Your analysis seems reasonable. But it's plausible that immigration can both (a) make a net contribution to government finances and (b) place "public services and housing access...under too much pressure" (at least in the short-medium term). This depends on the scale of immigration, and the speed at which additional services, infrastructure, and housing can be developed. Some things can be developed quickly, but others might take decades (e.g. major new transport infrastructure). In recent decades the construction of new housing (and supporting public services) does not seem to have kept pace with the relatively rapid growth in population, mostly driven by immigration. 

I agree that we shouldn't only care about the perspective of humans. But if humans aren't around then much of the potential energy on Earth will simply go unused (unless another technologically advanced species evolves or visits Earth from elsewhere). So yes, this would be a waste.

energy can neither be created nor be destroyed, it is naturally a zero sum game

While energy cannot be created or destroyed at the level of the universe, this doesn't mean it's a zero sum game from the perspective of life on Earth. There is a huge amount of energy available in the form of atomic energy, solar energy, tidal energy etc that is simply going unused. If humans use this, no-one loses out.

The amount is related to the value by some constant, unless you’re implying a time factor

Yes, I and others have explicitly been saying time is a factor, e.g. see my 2 examples above and comments by others. The amount is likely not related to value by some constant. The value that a given amount of money can buy will vary over time. 

but as far as I can see, the timing concern is a red herring, as in my model the pump is already primed and wealthy enough donors are dying in week one. 

I'll be honest, I don't understand this point, or why it means the value of a donation won't change over time. 

I may just be misunderstanding. But I don't think there's much more to say on this, unless e.g. you're able to share your model on Excel or Google sheets.

results in more money per unit time donated within the population, that would seem to be more effective to me

This is still only considering the amount of money donated, not the value of what the money can buy.

No, I don't understand your point. The fact that some people are dying and donating now doesn't answer the question of whether people who are not dying now should donate or invest now.

I don't think it's specifically about the EA population.

The value of donations may change over time. Your model shows that investing results in having more money to donate in the future. But it doesn't seem to take into account the value of that money (or the value of what the money can buy). This might change over time. 

A couple of examples:

• Assume everyone invests now rather than donates.
  • But in the year 2035 humanity is destroyed .
  • The value of the investments then becomes zero. We would have been better off donating to help prevent whatever caused humanity's destruction.
    • (Tobias makes this point in his footnote above - 'If there’s an existential catastrophe, donating at death won’t matter anyway'.)
• Assume the world continues to get richer, and the poorest benefit the most. The world's poorest increase their income from £1000 per year now to £4000 in 20 years time.
  • The value of your investments double in this time, so you are now able to donate £2000 to someone instead of £1000.
  • But donating £2000 in the future to someone who has £4000 is plausibly less valuable than donating £1000 today to someone who only has £1000.
    • This also relates to ogtutzauer and Henry Howard's points - the sooner the recipient receives a donation, the faster they can invest it.

Those are cases where the value of the donation declines. There could be other cases where the value of donation increases - perhaps as a result of new research showing how resources can be used more effectively, or a new treatment etc. In this case, there would be more money in the future (due to returns on investment) and more cost-effective things to spend this money on.

Thanks, this is helpful. I think I was wrong, and as you/Diana suggest scallops actually have a more developed nervous system than mussels

This is a good suggestion.

My (limited) understanding is that scallops might be even better than oysters and mussels as they are typically larger (so fewer are killed to obtain a given quantity of protein) and are possibly even less neurally developed (edit: this seems wrong - see below)

I also wonder about wider ecosystem impacts. As @Vasco Grilo🔸 has suggested, the impact on soil invertebrates may dominate the moral value of farming on the land - but there is huge uncertainty. 

I'd be surprised if there is a similarly large population of aquatic organisms that are impacted by the farming of bivalves (scallops, oysters, mussels). If so, they may be a more morally robust option than any land-derived option, whether animal or plant. But I've not researched this at all (I've tagged Vasco in case this is something he wants to look into!)