In his classic "The Theory of the Leisure Class", published in 1899, he argued that once the basis of social status became wealth itself – rather than, say, wisdom, knowledge, moral integrity, or skill in battle – the rich needed to find ways of spending money that had no other objective than the display of wealth itself. He termed this "conspicuous consumption".
Why Pay More? by Peter Singer - Project Syndicate
We can adapt that judgment to the man or woman who wears a $30,000 watch or buys similar luxury goods, like a $12,000 handbag. Essentially, such a person is saying; “I am either extraordinarily ignorant, or just plain selfish. If I were not ignorant, I would know that children are dying from diarrhea or malaria, because they lack safe drinking water, or mosquito nets, and obviously what I have spent on this watch or handbag would have been enough to help several of them survive; but I care so little about them that I would rather spend my money on something that I wear for ostentation alone.”