> the US government subsidizes the overproduction of food so that we do not experience famine in the event that a significant portion of the food supply gets taken out (e.g. bad harvest, drought, etc).

That's the first time I've heard that reasoning, and not that the farm lobby had enough power to obtain subsidies. What evidence is there that the subsidies (from taxpayers to the farms, many run by large companies) are driven by some kind of famine protection?