"Everyone can afford it, so I must"

Start with the belief that makes the table's pace feel like a fact about incomes. They can afford Lisbon. They can afford the second bottle. So it must be affordable, and if it's a stretch for you, that's your problem.

What you can see at the table is what people spend. What you can't see is what it costs them. Nobody at the restaurant announces their salary, their mortgage, their overdraft or the balance on the card that the sixty-eight pounds went on. The spend is public and the finances are private, and you're inferring the second from the first, for six people, none of whom you'd dare ask.

Robert Frank and colleagues, in a 2014 paper, set out a model of what they called expenditure cascades. The idea is that people's sense of what's normal to spend is set by the people just above them on the income scale. When that group spends more, the standard shifts for the group below, who spend more to keep up, which shifts it for the group below them, and so on down. The authors tested the model against how savings rates respond to changes in people's own income and in the income of others, and found it predicted patterns that the standard models couldn't. It's a model, and models are simplifications, but the mechanism is the one to hold. The table isn't the top of anything. It's keeping up with the group above it, who are keeping up with theirs.

A queue is a fair comparison for two sentences. Each person watches the one in front and steps forward when they do, and nobody in the queue can see what's at the front.

So when you look at the table and conclude that everyone can afford it, consider that everyone at the table is looking at someone and concluding the same. The friend who ordered the second bottle is keeping up with her sister's friends. The neighbour's kitchen was chosen after a dinner at a house with a bigger one. The colleague's car was bought because of the cars at the level above. Nobody at your table is sitting comfortably at a pace they set. They're all in the queue, and what you take for their ease is the back of their heads.

I'm not saying your friends are struggling. I'm saying you don't know, and neither do they about you, and the belief that the table's spend reveals the table's means is the belief that keeps the cascade running.