Why the poor pay more for toilet paper and just about everything else

Clarification, for the benefit of the sibling comments: inflation screws the poor because

(1) the poor are most likely to be on either fixed incomes, or incomes where cost-of-living adjustments are substantially time-delayed relative to the increased cost of living, and

(2) they're least likely to have any sort of hedge against inflation or sudden shocks to the system, such as having a paid-off house, a fixed-rate mortgage, adequate savings to handle an emergency, or investments in assets other than plain ol' US Dollars That Only Come In On The First And Fifteenth.

The middle class weather inflation just fine -- they're likely to get yearly raises that outpace inflation, to have savings to be able to handle unexpected price increases, and to have at least some assets that keep up with inflation even if their liquid accounts don't. And the wealthy benefit from inflation, because their factories keep producing widgets but their labor costs go down relative to the price of widgets.

The poor buy toilet paper? When I was a dirt poor student, it was assumed that one would simply take two or three or etc doses extra, whenever one was in a public bathroom.

Having actual tangible wealth is not necessary. One can opt to join the army and fund college via the GI Bill, for instance.

And generally, opportunity cost tends not to be super high when you don't have skills or an education.

But the Vimes theory was being offered to explain socioeconomic inequality within a society and depends on the "poor" options being more expensive per unit, while the microfinance successes happen mainly via investment of from richer countries into poorer ones, where they have lower prices per unit. (i.e. a dollar buys a lot more stuff in the third world).

IOW, to the extent that microfinance has successes, it's in situations that have the opposite dynamic of the Vimes example and do not count as an implication of the theory.

I have three people I point to for how different the experience can be.

One friend was living on disability (about $570/month) and food stamps (about $140/month), in a group home. His one "luxury" was he'd buy GI-Joe figurines every month, for about $20. At one point he asked me to take him to the store because he wasn't going to be able to walk the 10+ blocks that day. As he was shopping, I realized he had something like 30 pounds of meat in his cart and almost nothing else. I told him to put half of it back and add a bag of potatoes, and that whenever he wanted to cook meat, cook half as much as he normally would and replace the rest with potatoes. It was life-changing for him -- he was able to eat every day, and had enough money left over to start buying things like toilet paper in bulk. I've since lost track of him, and I'm sure he's still poor, but he's a more secure grade of poor than he had been.

Another friend was a divorced mom, recently remarried to a disabled man. She's unable to handle a full-time job, but works a few days a week as a substitute teacher. Between disability, child support, and work she makes maybe $1500 a month. She's always bought in bulk, usually splitting orders with her parents and siblings who live in the same complex. The only real escape from poverty she has is to recover from psychological trauma to the point that she can work full time.

Third is a young couple, both just turned 20, and their son is 3 years old. He's had adequate work for a while, but hides financial information from her, they both have expensive phones they use for things my old prepaid Moto X can do for a lot lower price, and they both have a tendency to eat fast food even though he works at a grocery store that has a good selection and good prices. The two things that have kept them from disaster for the past year: I let them live in my basement for a token amount of rent that I stopped collecting after a few months, and his grandparents have helped them pay off a couple of surprise expenses. She recently found work, and with two incomes they're able to afford their own place fairly comfortably, but for a while there it looked like they were going to get into a bad cycle like the one detailed in the article.