A theory that tells you the reverse is not a moral theory though.

His argument is valid because, whether he realises it or not, its based upon some assumed values. If you value everyone equally then his argument is pretty good (outside of the faults I already mentioned). However, if you dont have that value then his argument simply doesnt apply to you. Values are perspective based, and so the conclusions of moral arguments are aswell. This is true whether or not he personally thinks of his argument this way, I dont know his position nor care. — Ourora Aureis

Of course, if you reject a key premiss of the argument, you will reject it, on the grounds that it is unsound, rather than invalid. I get that.
But I don't reject that premiss. I think that it is badly formulated and wrong for that reason. I'm not sure whether that means the argument is invalid or unsound and that's a secondary issue. But I expect you won't care about that.

quote="Count Timothy von Icarus;917606"]There is a sort of reverse collective action problem here (I am blanking on the proper term). The argument might work for an individual or family. It can't work for everyone. If everyone stops all "unnecessary" economic activity in the developed world those economies will collapse, massively affecting global trade, agricultural production, vaccine production and development, etc. This would probably also reduce global stability and security. And then this would probably have a net negative impact on the developing world, both in the short and long term[/quote]
So the term you are looking for might be "negative feed-back cycle", perhaps?

You say that as if it's a bad thing. All the positive things modern societies can produce are already largely displaced by economic activity that is deemed more profitable (vaccines vs. erection pills, ending world hunger vs. over-processed foods, etc. etc.). — Benkei

There's no easy answer to this. There's no difficult answer either. But it is clear where we need to look. Start with the difference between "the positive things that modern societies can do" and "economic activity that is deemed more profitable". You "deemed" identifies the problem, or part of the problem. One can recognize that positive activity may not be profitable. But one can also recognize that making a profit can also be positive.
The misalignment bites because money is not just an accounting measure, but a proxy for resources. Whoever controls money, controls resources. If the profit and positivity were aligned properly, our resources could be directed properly . See, for example Happiness index - Wikipedia

This is not a perfect definition of the problem, but it is a start.

‘Even if we act to erase material poverty,’ Kennedy said, ‘there is another greater task. It is to confront the poverty of satisfaction….. that afflicts us all.’ Americans have given themselves over to ‘the mere accumulation of things.’
‘Our Gross National Product now is over 800 billion dollars a year. But that Gross National Product counts air pollution and cigarette advertising, and ambulances to clear our highways of carnage. It counts special locks for our doors and the jails for the people who break them. It counts the destruction of the redwood and the loss of our natural wonder in chaotic sprawl. It counts napalm and counts nuclear warheads and armoured cars for the police to fight the riots in our cities. It counts . . . . the television programs which glorify violence in order to sell toys to our children. Yet the Gross National Product does not allow for the health of our children, the quality of their education or the joy of their play. It does not include the beauty of our poetry or the strength of our marriages, the intelligence of our public debate or the integrity of our public officials. It measures neither our wit nor our courage, neither our wisdom nor our learning, neither our compassion nor our devotion to our country. It measures everything, in short, except that which makes life worthwhile. And it can tell us everything about America except why we are proud to be Americans.’ — Robert F. Kennedy, Remarks at the University of Kansas, March 18, 1968

There's no easy answer to this. There's no difficult answer either. But it is clear where we need to look. Start with the difference between "the positive things that modern societies can do" and "economic activity that is deemed more profitable". You "deemed" identifies the problem, or part of the problem. One can recognize that positive activity may not be profitable. But one can also recognize that making a profit can also be positive.
The misalignment bites because money is not just an accounting measure, but a proxy for resources. Whoever controls money, controls resources. If the profit and positivity were aligned properly, our resources could be directed properly . — Ludwig V

Profit and "positivity" are perfectly aligned in crisis, which is why the rich get richer in every crisis. Alignment doesn't resolve anything.

My objection is based on 4 points: 1) the limited view of causation 2) what the argument actually does in reality 3) lack of focus on the power players. These are not distinct areas. 4) ill-defined category: need.

The connection between these criticisms could be put in a question: Who is going to listen to this argument and what does that entail?

Most people will not listen to the argument, some will. Who will those people be? Well, people who tend to feel guilt, compassion, religious duty. Will the power players, who promote consumption, profit off of it and frame the way markets work be affected? Not much, I think. Yes, if a grassroots movement arose, corporations would have to adapt, but given their control of media and focus, I think this is unlikely. What happens when people who tend to have compassion are the mains ones affected? They give up their digital devices, cars if they can, live more simply, have less resources and, I think this leads to them having less effects on the world. What does that lead to? I don't know. But we can't pretend the causation is limited to the moment money goes one way or the other. What is need? (it's ad hom to focus on Singer, but he does have three children. That third child, before he or she existed, had no needs, and all the future expense of that child could have supported at the very least a number of needy, starving already existing children. Did PS need that child? Now that's ad hom and he could have a great argument and not quite follow it, but it did lead nicely to what I think is haziness around need - and then in addition limits around what the effects of the argument, should it be widely effective, would be. Can any Westerner really justify having a child or another child? At least if we look at it in the argument's choice moment money goes here or there approach.

One other effect of the argument generally not thought of is that those who hear the argument, but for whatever reason do not follow it, may well feel guilt. One can argue that, well, they should. But 1) people feel guilt not just from useful/valid arguments 2) this addition of guilt isn't helping anyone, and that guilt is not going to bite on the power players and sociopaths. It may even have detrimental effects when decent people feel worse about themselves.

One could argue this is a deserved side effect and will be outweighed by the positive effects of the argument. I just don't think that's the case.

The argument it seems to me functions as a kind of guilt trip, I think, and affects the wrong people.

We often look at the truth of an argument as what truths it contains. A little along the lines of Reddy's conduit metaphor idea, where we see communication as a kind of container/conduit for truth. I think it is important to look at what arguments do, not just analyze them in terms of what they contain. And to not just consider the effects that are easy to track as if less easy effects don't exist so we don't need to mention them.

Of course my sense of what it will do is speculative. But then, so would postive evaluations.

Profit and "positivity" are perfectly aligned in crisis, which is why the rich get richer in every crisis. Alignment doesn't resolve anything. — Benkei

I'm sorry. I wasn't clear enough about what I meant by "profit" and "positivity". Alignment doesn't, of itself, resolve anything. The issue is what alignment will produce correct results. Note the the alignment is produced by how you define profit and how you define positivity. (Both of the concepts are, of course, value-based).
As they are conventionally defined, the search for "profit" is defined in such a way that it tends to produce results that are, from one perspective, positive, but are negative (not positive) from other perspectives. The depth of this problem is clear when we remember that money is only worth what you can do with it. I'm sure there are many places that make the point, but I like this one:-

...that Gross National Product counts air pollution and cigarette advertising, and ambulances to clear our highways of carnage. It counts special locks for our doors and the jails for the people who break them. It counts the destruction of the redwood and the loss of our natural wonder in chaotic sprawl. It counts napalm and counts nuclear warheads and armoured cars for the police to fight the riots in our cities. It counts . . . . the television programs which glorify violence in order to sell toys to our children. Yet the Gross National Product does not allow for the health of our children, the quality of their education or the joy of their play. It does not include the beauty of our poetry or the strength of our marriages, the intelligence of our public debate or the integrity of our public officials. It measures neither our wit nor our courage, neither our wisdom nor our learning, neither our compassion nor our devotion to our country. It measures everything, in short, except that which makes life worthwhile. — Robert F. Kennedy, Remarks at the University of Kansas, March 18, 1968

In order to improve matters, we just need to make sure that profit is defined in such a way that maximizing profit also maximizes the things that make life worth-while.

BTW, I think, if you look more closely, that in a crisis, some rich people will make money, but not all of them. I agree, though, that turning a profit in a famine seems like an unacceptably callous thing to do.

In order to improve matters, we just need to make sure that profit is defined in such a way that maximizing profit also maximizes the things that make life worth-while. — Ludwig V

That's quite easy yet barely anyone is prepared to do it.

Yes. I'm afraid it's a pipe dream. The Happiness indexes are a step in the right direction.

Zakaat is in principle not enforced by government (even though in some countries it loosely is) but by religious self-discipline. If you don't want to do it, then you obviously don't. However, it is inculcated from a young age that it is a moral obligation, surrounded by quite a bit of social pressure. — Tarskian

H'm. Then it seems to be somewhere in between a tax and a charity.

Yes, I am in agreement with everything. The two philosophers' psychology just could be behind their motivation to devise an ethical theory alternative to the preceding ethics, which placed a lot of value on virtue. Virtue, pursuing a golden mean, requires common sense.

I think it’s absurd to believe that people should live miserable, spartan lives and wear hairshirts because other people in the world have bad lives until everyone has a good life. It’s the duty of those who wield the actual power in society (the state and the wealthy) to address the fundamental injustices and inequities that plague us. Not average citizens who have a right to recreation, entertainment and creature comforts. We have more than enough resources to give every person in the world a basically good life. It’s just a matter of ideology and unwillingness as to why it isn’t done.