Global trade boggles my mind. I'm on the back deck in Sydney, Australia, working on a project and realizing that I'm about to use screws that came from a hardware store (going out of business sale) in San Francisco, but were probably made in China... Meaning these screws have likely been across the Pacific twice before being put to use. And that, to me, epitomizes the state of modern global trade.
How could it possibly make sense for these screws to travel across the Pacific twice? Why, when moving to a new country, would I bring a packet of screws? As with global trade, overall it seems ridiculous, but the individual steps all make sense. The reality of the situation though is that we're all burning a lot of energy in absurd ways that could probably be eliminated, but it's easier to just keep going than to sort out what would maximize efficiency. Would / will the market sort it out? "The market" is what compelled these screws to travel twice across the Pacific! (presuming they were made in China - the insert says only "packaged in USA" meaning they were undoubtedly made elsewhere).
To explain my part of the insanity... I found out late when moving here that since my household goods were going by ship, weight did not matter. It was whatever would fit into a specific size shipping container. My future wife wanted to ship some furniture. In hindsight I could have added my motorcycle to the container. So when it came to my box of tools, of course, a packet of screws was entirely insignificant. We all know the economics that moved steel production from the US to China (it's all about cheap labor, and maybe pollution laws and cheap Australian coal); the economics that would allow me to bring a packet of screws back across are now easier to understand. The coal used to fire the steel that made those screws may have actually come from Australia.
I was surprised to find that the degree of global trade goes back as far as it does. The Balclutha is the last of great sailing ships - with a relatively modern steel hull made in 1886, Glasgow, Scotland, and now sitting at the Maritime Museum in San Francisco Bay. This graphic explains the various lives of that once-mighty ship.