I never thought I would seriously study arcane economic mechanisms like "the carry trade" but I've become convinced that I cannot understand the world around me without grasping at least the basics of arbitrage and the like. Perhaps the world was always ruled by financial elites who manipulate mechanisms that are foreign to common folk -- in fact, I'm sure of it -- nevertheless those mechanisms now assume an unusually blatant role in politics and I keep stumbling over my ignorance of them.