Thanks for this. I find that leakage very likely - and it seems obvious that one of the things that make China cheaper is the lower cost of enforcement of rules on security and pollution (there may be other costs associated iwht bureacracy and corruption, but that one certainly palys in favor of China).

As to cement and steel, there is the small thing that these goods are very heavy and extremely expensive to transport over long distances - thus made mostly locally everywhere, with a few exceptions for highly specialised goods. Heck, cement is still made right in the middle of Paris (right under my windows) - on the banks of the river.

In the long run, we're all dead. John Maynard Keynes