It's not just economics. It's politics as well as a dash of military theory. For instance, it's cheaper to produce steel and aluminum abroad than in the states

It's not just economics. It's politics as well as a dash of military theory. For instance, it's cheaper to produce steel and aluminum abroad than in the states. But we erect protective tariffs on steel and aluminum to keep those industries in the states so that in case war breaks out, our aggressors can't cut our supply lines, and we can keep churning out jet and tank parts. But agreed, it's a fascinating field. Why do you restrict the explanation to residents of SF, rather than all citizens of the US?