Week 3: The Exchange

Crossing 2's lecture — why a trade is only worth making if it's worth telling afterwards, and what that means for the clip you owe

10 August 2026

Open the slides

Half and half, like every lecture: George Curious on what a thing is worth when nobody has put a price on it, Yu Tobe on making a trade that survives being told afterwards.

George’s half — what’s it worth?

Crossing 1 was free. You spent attention and some nerve, and if it went badly you walked away no worse off. Crossing 2 has a price: you put a real thing up — an object, a favour, a tip, a skill — before you know what’s coming back, and you let the other person set the rest of the rate.

Money is banned, and that’s the interesting constraint rather than an arbitrary one. A price doesn’t value a social exchange, it ends one: Ariely is the evidence, with people who’ll cheerfully help you move a couch for free and refuse to do it for three dollars. Mauss is the framework — a gift obliges you to give, to receive and to repay, and a receipt settles the account instead. Make a Trade runs on the other set of rules entirely, and it closes on the question George will still be asking in week 12: not did you do it, but was it worth doing.

Yu’s half — make it worth telling

This is also where the video stops being a distant requirement. Yu spent years behind a camera and teaches the report-back the way a storyboard gets built: what you wanted, what you offered instead, and the bit you’d cut if you only had thirty seconds. Those are the three questions the room asks at The Exchange Rate, and they’re worth running against the trade you’re planning rather than the one you’ve already made.

It closes by sending you back to the clip you shot in Crossing 1 with one question: would you watch it if it weren’t yours? Five of those play in full at the end of semester — see Legacy — so the standard is worth setting now rather than in week 11.

What you should leave knowing

Teaching team