We found a very strange result, and that was that if you tax the low-fat, high-quality fruits and vegetables, you could actually increase the total amount of fat that people eat in the U.S. And if you tax the high-fat, low-quality things, you could actually decrease the amount of fat. That was because of the substitution among the food groups.
The problem with that study, I have to say, is that the numbers were very weak in terms of the way they were developed. So those are sort of preliminary results. The problem is that the data that are available don't line up as well as you might like, so I don't know how confident I am in that prediction.