Not just GDP but also nation-altering events such as warfare. I recommend "A Distant Mirror" by Barbara Tuchman if you haven't already read it, as it's a wonder

Not just GDP but also nation-altering events such as warfare. I recommend "A Distant Mirror" by Barbara Tuchman if you haven't already read it, as it's a wonderful book (medieval history, but it still applies here). Tuchman mentions our modern bewilderment at the insanely rash and reactionary decisions that were often taken by nobility in those times - declarations of war, terrible combat strategy and so forth, and which affected so many lives (mostly those of the poor). She goes on to speculate that these decisions make sense in the context of near-permanent drunkenness.