But the math against urban development is brutal. Rule of thumb I've read seems to be if cost of shelter in exurb is 1, then suburb is 2, mid-rise urban is 4, a

But the math against urban development is brutal. Rule of thumb I've read seems to be if cost of shelter in exurb is 1, then suburb is 2, mid-rise urban is 4, and high-rise urban is 8. To make that pencil out, people must be willing to trade off outsourcing much of their lives for much smaller living spaces. That outsourcing cost must not exceed their available income. Beyond that, the outsourcing has to rely upon a dependable logistical tail. While industries everywhere in modern commerce are becoming more brittle and fragile due to various incentive structures, this entire premise tower unravels and becomes increasingly tenuous. High-density living is effectively a mass-trust exercise; low-trust societies cannot sustainably maintain high-density cities over centuries, the only timescale where the long-term public and private financials modulate into a reasonable payoff.