Once you've decided to compare charities with each other to see which would make the most effective use of your money, can you avoid comparing charitable donation with all the non-charitable uses you might make of your money?

Peter Singer, to take one prominent example, argues that whether you do or not (and most people do), morally you cannot. To buy an expensive pair of shoes (he says) is morally equivalent to killing a child. Yvain has humorously suggested measuring sums of money in dead babies. At least, I think he was being humorous, but he might at the same time be deadly serious.