Where does this come from?

[james_davis_nicoll]

Two books written the better part of a century apart (For Us The Living and an upcoming book that I won't mention by name) have a similar plot development: after the old world [1] suffers a terrible calamity, the regions that were unaffected by the calamity cut off all trade to the affected region until such time as it recovers.

Why would this been seen as the right thing to do?

1: In the regional sense in the Heinlein and a more literal sense in the upcoming book.

Comments

[zeborah]

How heavy are sprockets? How much does it cost to hire someone else to push the widgets or sprockets?

[lederhosen.livejournal.com]

How heavy are sprockets?

Same as widgets. But only because I'm currently too lazy to work out the exact costs required for McGuffin transportation to make trade unviable. (If sprocket transport costs are negligible, Bob and Alice can make fifteen McGuffins every five days between them by shipping all the sprockets to Alice's place, but then Alice ends up with all the McGuffins, so transport costs arise in recompensing Bob.)

How much does it cost to hire someone else to push the widgets or sprockets?

Similar rates; Alice and Bob aren't exceptionally skilled, so would-be widget-pushers have the same sorts of options open to them. Again, because I'm too lazy to come up with slightly-cheaper-but-still-uneconomical numbers, but they do exist :-)