[shoo]

> Would this vector stop at length two? How about other "nudge" worthy metrics?

that's a good point. there's definitely other societal goals that can be nudged toward through prices.

but on another hand, i'm not sure thinking about prices as vectors is that helpful. to change behaviour a regulator needs a way to internalise the external costs into prices, or some equivalent mechanism, and some enforcement mechanism for non-compliance.

but if you have all that, it isn't clear what use price vectors are. and if you only had price vectors but the extra components weren't reflected in the price, with no enforcement mechanism, then they won't change behaviour.