liquidity, wealth, and consumer behavior

The Atlantic has a contribution to the "it's expensive to be poor" genre of article, and one of the things worth noting about this and most other examples is that the benefit here is generally to liquidity rather than net wealth; I think, though am not sure, that the price-discrimination related reasons that it can be more expensive to be wealthy than poor would track more with net wealth than with liquidity; they would probably track consumption more closely than either.