https://astralcodexten.substack.com/p/your-book-review-cities-and-the-wealth

Currencies, Jacobs explains, function as automatic tariffs (to protect local industry from foreign imports) and automatic export subsidies (to encourage local industry to export). They are “automatic” because of the feedback mechanism. Just like an accelerated breathing rate, they take effect exactly when they are needed — and no longer. 

Jacobs claims having a local currency serves as a feedback mechanism that has served to encourage cities to substitute imports / develop internally, which has contributed significantly to historical economic growth - but having a national currency cuts off this feedback loop, and is bad.

My initial impression is this is wrong and misunderstanding economics somehow. But I haven't thought about it at all yet. I'll think about it more and read the comments on the post and here, and resolve in a week

More specifically: This resolves YES if I think the idea is, something like, a good idea worth looking deeply into / has a >25% chance of being true / etc. Resolves NO if I think the idea is <25% chance of being true / is basically just confused. Yeah, wishy-washy criteria.