[throwaway218649]

> For most of history economies were fighting against scarcity, working to produce as much as possible to keep people alive. It is only in the past 100 years that we have had a problem with too much productive capacity.

That really does not describe hunter-gatherer or feudal economies. And it's not even true for capitalist economies: for instance, there were periodic gluts of cotton (1820s, 1860s), or in the textile products made from cotton (1850s, during a global economic crisis). Famine has different causes, independent of the economy: either deliberately caused by forced displacement (ex: Irish famine), or a result of local weather patterns (for any geographic region, there will be a weather event, like drought or late/early frost, that will cause harvest failure roughly every 15 years). Improved shipping, which in a positive feedback loop was the cause of and response to increased trade, is largely what is responsible for eliminating famine. You first of all need to be able to ship grain to a region that is experiencing famine (agricultural over-production in a different region does nothing to prevent people from starving to death otherwise), and the region experiencing the famine has to have something to trade for the grain (people have, and continue to, starve to death in places that experience agricultural surpluses).