I haven't thought about this enough to come to a conclusion personally, but the argument phrased non-horribly would be:
"I would be ambivalent between living 1 year in a first world country, then dying, and living 3 years in a 3rd world country, then dying. If I treat everyone the same as myself, then I should be ambivalent between 3 years of life for someone in the first world and 1 year for someone in the third world."
However, one huge problem with this is you're taking your own morality and imposing it on others.
ETA: Re-reading the original post, it doesn't look like it's saying that first world is worth 3 times third world. It's saying that assume that you don't value your personal life more than 3x a random other person's, which is an entirely different argument.
In my last post I wrote about how Peter Singer’s implicit past claim that [one can save a child’s life for the cost of a pair of shoes] is misleading.
Having said that, it’s important to highlight that if one ignores indirect effects, funding bed net distribution to save lives is an extremely good opportunity for people in the developed world to increase the number of valuable years of life that people experience.
The situation is probably completely different when one considers indirect effects. I’ll postpone discussion of indirect effects to a later date.
Consider the question of what the quality of life is in the developing world. The GiveWell blog post Quality of life in the developing world reads:
The reader can draw his or her own conclusion from this. It seems likely to me that the average life in the developing world is worth living, and that the value of an average year of life in the developing world is no more than 3x lower than the value of an average year of life in the developed world.
In my last post, I wrote about how the explicit estimate for Against Malaria Foundation’s marginal cost per life saved is $2k, and the fact that the actual cost could be significantly higher owing to Bayesian regression.
Note: I formerly worked as a research analyst at GiveWell. All views are my own.