Mandatory labelling is obviously a very topical discussion.
There are a couple of pieces to this issue. One is that labelling can be done at any point in time. In fact, I looked at a bag of pretzels on my countertop the other day and it says, “Contains no genetically modified organisms”. If you look at the organic movement, you notice that we didn't label for non-organic food; instead, we allowed the organic movement to put on labels saying it's organic. That, I think, is the better way to go, because we know of no scientific evidence to show that GMOs are causing any harm. I would advocate that we keep labels reserved products that we know will harm you: tobacco, peanuts, alcohol. We know there is scientific evidence that shows that those types of products can harm you, and we should reserve the labelling for that. Otherwise, we get to a place where products start to look like NASCAR cars with stickers all over them, making it very hard for you to discern exactly what you're supposed to be worried about and what you should really pay attention to. There's probably a market discipline that needs to come into play that would allow for labelling to take place.
The other challenge with labelling is less about the cost—although we've heard that argument thrown around—and more about how you regulate it once you've put a label on it. It's very easy to say it contains nothing, but how do you scientifically demonstrate that there is no trace of GMOs in a product, as you could do with peanuts? In the peanut world, you see “may contain trace elements of peanuts” or it has absolutely no peanuts.
When I used to work for the forest products industry, it had a similar challenge. It's very easy when you have a piece of lumber that comes out of a tree. You could stamp it and say that it came from this forest and that it was certified to this level. When you get into the pulp world, where you're combining chips from a number of different sources to make the pulp that makes the paper, it's very hard to make sure that all of your upstream sources are certified to the same level.
In the food world, I think it would be the same problem. You could probably certify that steak came from a cow that came from a producer. When you get into things like chips and cereals, though, that involve a number of different sources, it would be very difficult to have any certainty that you could actually put a label on that.