American food policy has long been rife with head-scratching illogic. We spend billions every year on farm subsidies, many of which help wealthy commercial operations to plant more crops than we need. The glut depresses world crop prices, harming farmers in developing countries. Meanwhile, millions of Americans live tenuously close to hunger, which is barely kept at bay by a food stamp program that gives most beneficiaries just a little more than $4 a day.