Really strong essay taking on many of the arguments of the locavore movement. Though I do think that there are some good elements that usually come with it that extend beyond simply buying local. Locavores tend to pay a lot more attention to the food they put into their bodies. While the values with which they judge the food I may not share, it's hardly a bad thing to be a more educated consumer (in two senses of the word, I guess). And buying local may help instill an appreciation for one's own culture, which I think can have positive benefits for that person and their relationships with those around them.
But on the economics, they knock this one out of the park. It's international protectionism writ small. To their credit, I suppose, the application of protectionism (imports are bad!!1) within a national economy for the 'benefit' of local economies shows that not all protectionists are xenophobes. One doesn't often hear, "I don't want to buy no tomato grown by no Californian!" the same way one might hear, "I don't want to buy no car made by no Koh-Ree-An!"
One of the amusing parts of the locavore movement, though, is how easily the principles are set aside. The theme of this month's issue of Saveur is 100 favorite things sent in by lots of favorite chefs. Included in the list are some up-and-coming chefs recommended by more established chefs. A common compliment is that the chef has built their restaurant around the principle of buying locally. And then many other items are where chefs have written in about their favorite, exotic ingredient from around the world. What are the environmental impacts of flying in authentic Japanese ingredients? And how does that "keep the money in the local economy?"
The locavore movement has also unfortunately attained some of the more annoying trappings of similar such issues (like recycling). Like the litmus test ("What do you mean you don't buy local!?") and the orthodoxy ("What do you mean grass-fed beef causes more pollution!? You're a right-wing, knuckle-dragging, science-hating cretin!"*). And like similar such issues, where persuasion fails, the activists threaten to turn to coercion. Everyone should be free to buy locally. No one should be forced to.
* or, "What do you mean recycling plastic is a net negative for the environment!?"
FTR, I think recycling makes sense for some things. Just not everything. Of course, I'm adding this disclaimer because I fear the social scorn that comes with hinting that recycling everything that you can isn't necessarily the best thing, economically or environmentally. And that's what the locavore movement is turning into.
(cross posted from my Facebook page, but fleshed out a bit more)