Tyler Cowen is one of the best economics bloggers around. He recently took on ace environmental writer Michael Pollan’s new book, The Omnivore’s Dilemma: A Natural History of Four Meals in Slate, and it was like watching Brian Urlacher try to take down Tom Brady, and almost as rare. Money quote:

“Pollan makes much of the energy costs incurred by the long food-supply chains of American grocery stores. It may look like we are eating Chilean grapes, he argues, but in fact, once we consider transportation costs, we are guzzling petroleum.

“Economics offers a clearer view of what is going on. We do need to save energy, but it is difficult for a central planner (or for that matter a food commentator) to identify what is waste, relative to the costs of eliminating it. We should rely on higher market prices, if need be with the assistance of taxes, to increase conservation. If fuel becomes more expensive, we’ll likely adopt peak-load energy pricing, and drivers may scrap their SUVs for hybrids. But we probably won’t plant grapes in our backyards. While we must conserve energy, we cut back where it makes the most sense; grape-shipping is not the place to start. Global trade does involve transportation costs, but it also puts food production where it is cheapest, again saving energy by economizing on costs of labor, irrigation, and fertilization, relative to the alternatives.”(Read the whole thing.)

This isn’t the last word, of course. Economists are prone to assume that the product being shipped is like a bunch of unbreakable billiard balls. Farmer/researcher Frederick Kirschenmann, writing in the Science and Environmental Health newsletter, “The Networker,” suspects that long-distance food may be one of the reasons why fruits, vegetables, and wheat have declined five to thirty-five percent in nutritional value in the last fifty years: “While fruit and vegetables may be genetically altered to retain their appearance during this long trip, vitamins are lost over time and protein breaks down. So the trip not only adds a ‘fuel tax’ to the cost of food, it may also deliver food with reduced nutritional value.”

[BTW, peak-load energy pricing is already happening in Chicago: check out the Center for Neighborhood Technology’s Community Energy Cooperative, which may be taking new members next year.]