Surprised that someone of Krugman's economic intellect actually stated that "the invisible hand works well in agriculture." Unless he had in mind the development of futures markets and alike to smoothen out the wild price swings (due to unpredictable weather patterns wreaking havoc on seasonal harvests.. now further compounded by climate change), I can think of much better examples than that sector... not to mention the negative impacts of agricultural trade liberalization on income distribution in many farmers of both Western and developing nations alike (which by the way he mentions in this interview, though on a different tangent). Most of what he says makes sense, but this was just such an obvious blunder to pass.. don't know if he intentionally made it or actually believes in it which is concerning as it clearly goes against his own Keynesian tenets.