For me it’s a question of competing ethical behaviors. Yes, giving money to alleviate human suffering is an ethical good. I’m not sure anyone is actually positing that it’s not ethical to give money that could be spent on luxuries to help alleviate human suffering.
However, neither is it ethical for me to strip my life of all “luxury” items in order to give every cent over and above basic subsistence to any cause, no matter how worthy. For several reasons. First, because I’m aware of the affect that would have on my own personal morale. And it wouldn’t be pretty. Not because I’m a bad person for feeling the urge to eat well (as opposed to subsisting on 15 for a dollar top ramen so that I may send the remainder of my grocery budget to a charity of my choice), but because I have ethical qualms about treating anyone in a shabby fashion, including myself. Second, any changes I make in my lifestyle do not affect only myself - I have my SO to consider and one day soon I’ll have my children to consider. Is it ethical to deprive them of luxuries so that we may POSSIBLY benefit someone else? Third, I have duties and responsibilities other than to do everything in my power to alleviate human suffering. Fourth, because I’m not convinced of the utility of donating money in the cause of alleviating human suffering.
To elaborate on the fourth point: As has been pointed out a couple of times previously in this thread, a sizeable proportion of human suffering is taking place under circumstances such that mere application of fundage will not actually serve to alleviate the suffering. Given my income, geographic location, lack of skills that would be of service to alleviate suffering (no medical training, agricultural expertise, etc) and aforementioned other commitments and responsibilities, the only feasible way for me to translate the cash that would be spent on “luxury” items into alleviation of human suffering is through the time-honored medium of donating it to the charity of my choice. According to the American Institute of Philanthropy, in order to make their top grade for efficiency (the amount of cash actually getting to the intended recipients as opposed to being chewed up in administrative fees and expenses) you must get 75 cents on the dollar to the intended recipient. That’s the stat for the United States, where infrastructure isn’t a problem, where internal warfare isn’t a problem, where distribution mechanisms are at their best. I’d venture to say that most of the world’s suffering is taking place in locales who lack infrastructure, distribution mechanisms and peace. So at BEST in the US, only 75% of my charity dollars are hitting target - and that percentage starts dropping out of the US (where the suffering is more prevalent in my opinion).
Also weighing in is my knowledge that in many cases, there is already more than sufficient fundage if not to totally end suffering, then to drastically reduce it. The problem isn’t lack of money - it’s lack of other things. Giving my money to charities serving those needs is WASTE. They have the money they need! What they need is an end to warfare. Or possibly infrastructure (roads, for example!). Potentially a distribution scheme to get the materials to the people who need them. More money won’t solve the problem. Stripping my life of luxuries only to provide essentially futile contributions (in the sense that lack of funds isn’t the baseline issue in many cases) isn’t an ethical good for me. It’s wasteful.
Quite a lot of this is also a question of scale. If it’s a question of foregoing a gourmet dinner in favor of giving someone the money they need to have lifesaving medication, it’s a no brainer. Show me where to sign up! But the problem with this as an ethical question is that as you scale it up from a specific case to a general case, the question doesn’t travel well. There are ethical questions that scale up and down easily (Is murder ever ethical, is it ever ethical to cheat on your wife, etc etc etc). This isn’t one of them. The mere knowledge that there are people suffering (starving, dying of easily cured disease, etc) does not render spending decisions ethical or unethical on their face. There will ALWAYS be people suffering. There will always be people who starve. Or die of easily treatable diseases. There will probably always be war. The mere fact that there are people suffering does not per se make my decisions to purchase luxury items unethical. Just like the knowledge that there are people dying from treatable disease does not make my decision NOT to pursue a career in medicine unethical. While I agree that being a doctor is a fine, ethical choice, that does not make a decision NOT to pursue a career as a doctor an unethical choice.
Basically, it’s not an all or nothing proposition. Giving money to charities does not make the decision to use some money for a luxury item per se unethical.