Wednesday, July 16, 2014

The true externalties of a burger?

I applaud Bittman's valiant effort to calculate the true externality cost of a burger. Too often people make a big deal of externalities that really only add up to pennies. However the numbers he comes up with is a vast over-estimate.

The numbers don't add up. First of all, counting burgers as 11% of the obesity epidemic is way too high. Burger calories is really only a small portion of fast food calories (soda and fries are greater). And not all calories contribute to obesity. Only surplus calories. Calories eaten to keep us at a healthy weight should not count. So really the obesity calculation is maybe 10 times too high. Similarly, I checked the math on the carbon calculations. The White house number is actually fairly middle of the road. A summary of the academic literature (see Tol 2008 and follows up) finds numbers much lower than the White house number (and much lower than those produced by special interests groups). So I'd call the 15 cents for the price of carbon an upper bound. But even using the White House number, the math seems off, a quarter pound of burger (the weight of cheese here is small) is 0.0028 metric tons * $37, that's only 10 cents of externality, not the 15 cents he states.

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