What's complicated about #centralization vs #decentralization is that neither is the optimum. Not only is it a shades of gray thing, but any non-trivial system is likely going to have both more and less de/centralized parts.
The US transportation system that @mmasnick is talking about is a great example. Almost completely centralized traffic rules and road funding. Federated construction. But enabling decentralized, localized innovation in use and economic benefits.
