For the first time today, I saw the following label on a packaged food.
In a way, the label seems a little odd. An organic seal on a product should already convey to consumers that the ingredients came from a process that excluded GMOs. However, the very presence of the label suggests many consumers may not be aware of this fact.
I have a paper with Brandon McFadden forthcoming in journal Applied Economic Perspectives and Policy (sorry, I don't yet have a link to the paper on the AEPP's website; I'll pass it along when I get the link and discuss the whole paper in more detail). In the paper we delve into this issue and others. Here's part of the motivation.
We ultimately find that products with the organic seal and products with the non-GMO verified seal are indeed demand substitutes. Here's one paragraph related to those results:
Because it is more costly to be organic than non-GMO (since the latter is a subset of the former), it is easy to see why many food companies would want to add the additional label that "Organic is non-GMO and more".