# Some railways left third class open to the rain. A roof would cost almost nothing.

- Series: [The Better Guess](https://miu.fm/thebetterguess.md)
- Published: 2026-10-21
- Page: https://miu.fm/thebetterguess/some-railways-left-third-class-open-to-the-rain-a-roof-would

## Story

Some railways left third class open to the rain. A roof would cost almost nothing. Why leave it off: to save money, or to scare off the rich?

In the 1840s, some French railways ran third class open to the sky, on wooden benches, and people called it barbaric. In 1849 an engineer, Jules Dupuit, explained it. A railway can't tell by looking what each traveller would pay. Charge one fare and everyone below it stays home. So the railway sets up classes and, in his words, lets the travellers sort themselves. In his own example, two classes carried more people than one fare, earned more, and left the riders better off.

But only if those who can pay for second don't ride in third. So the roof stays off: "it hits the poor, not because it wants to hurt them, but to frighten the rich."

A coupon works the same way: the low price goes to whoever spends the time to clip it. When the cheap version is worse on purpose, the worse part is a price tag for people who would pay more.

The dot chart is our sketch of Dupuit's example (his totals at each fare; the split above 6 is ours). His words are quoted in R. B. Ekelund's English translation.

So, which did you pick?

Sources: Jules Dupuit, "De l'influence des péages sur l'utilité des voies de communication", Annales des ponts et chaussées, 1849 (English in R. B. Ekelund, Quarterly Journal of Economics, 1970); Chakravarthi Narasimhan, "A Price Discrimination Theory of Coupons", Marketing Science, 1984.
Sounds: our own, made in code (earshot, CC0).

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