1. "Last year there was much discussion on California's Prop 37, which would have mandated labeling of genetically engineered (GE) ingredients. After enjoying strong a strong lead in the polls, Prop 37 actually failed to garner a majority of votes, and thus did not become law. One year later, Washington State now has a similar initiative up for vote (the text of the law is here; a few more details are here)."
2. "Here is Cass Sunstein, Obama's former "regulatory czar" had to say on the issue: "Any such requirement would inevitably lead many consumers to suspect that public officials, including scientists, believe that something is wrong with GM foods -- and perhaps that they pose a health risk. Government typically requires labeling because it has identified such a risk (as in the case of tobacco) or in order to enable people to avoid or minimize costs (as in the case of fuel-economy labels). A compulsory GM label would encourage consumers to think that GM foods should be avoided."
I agree with Lusk and Sunstein. If getting GM (or non-GM) foods matters to you, you do have a choice. You can obtain non-GM foods by buying organic. But by mandating labeling of GM materials, there are two potential costs. One is that producers may make (expensive) changes to their products to make them non-GM, which will increase grocery bills. Given that increases in grocery costs will most affect the poor, you could expect worse diets mainly among those with lower incomes.
The question I ask to everybody who doesn't follow the issue too closely (and often has a default bias of "sure, let's label them) is: "How much of an increase in obesity would you find acceptable in order to label foods as GM?"
The second cost is very related to the first. If producers don't make changes, then products will be labeled as GM. Those who are less intelligent/informed are not going to realize that GM-free does NOT mean healthier. Because time and attention at the grocery store is limited, there will be people who pay attention to the GM-label but less attention to the nutrition qualities of food and their diet will deteriorate.
I know the federal government spends a fortune trying to get people to eat healthier. Much of this is aimed at those with lower incomes and education levels. (I actually think too much is spent on this, but that's another issue.) This type of law would have the opposite effect. It would focus on irrelevant characteristics and would lead those who are poorer and those with less intelligence (or who are less informed) to eat worse foods.
The more-vulnerable socioeconomic groups will suffer if this becomes law. The left likes to claim they look out for vulnerable groups. On this issue, that's clearly not true.