From EconLib:

Oklahoma's government, like those of 45 other states, funds a farm-to-school program encouraging cafeterias to buy their food from local sources. U.S. Representative Chellie Pingree (D-Maine) wants to help; she recently introduced the Eat Local Foods Act (HR 5806) to assist schools in providing local foods in school lunches. From Michelle Obama's White House garden to grants from the U.S. Department of Agriculture's "Know Your Farmer, Know Your Food" initiative, an agenda has emerged to give local foods more prominence on our dinner plates. Interestingly, no agricultural economist has informed the public that a key claim of local-food advocates—that local-food purchases enhance the local economy—violates the core economic principles taught in every introductory economics class. Until now.

The Locavore's Dilemma: Why Pineapples Shouldn't Be Grown in North Dakota