Support for GMO Labeling a Left-Wing Phenomenon?

Much has been written about whether aversion to biotechnology and GMOs has ideological dimensions rooted in the left.  I've written about this before, as have many others (this paper in Food Policy extends the discussion to a whole host of food regulations beyond biotechnology).  Most of the studies I've seen (including my own data) suggest only small differences in the left and the right in terms of beliefs about safety of eating GMOs.  However, as I previously argued:

One distinction, which I think is missing, is the greater willingness of those on the left to regulate on economic issues, such as GMOs, than those on the right. Stated differently, there are questions of science: what are the risks of climate change or eating GMOs. And then there are more normative questions: given said risk, what should we do about it? Even if the left and the right agreed on the level of risk, I don’t think we should expect agreement on political action.

Perhaps the clearest demonstration of this difference in willingness to regulate comes from a new paper by John Bovay and Julian Alston in the Journal of Agricultural and Resource Economics. They look at precinct-level voting data on the Prop 37 mandatory labeling initiative in California in 2012. One of the best predictors of support for Prop 37?  The share of people in the precinct voting for Obama. Here's a telling graph from their paper.   It's an almost perfect positive, linear relationship. 

The authors went on to use these results to predict what would have happened in other states if they'd had an opportunity to vote on Prop 37 (I should note we did something very similar in a paper on for votes on California's Prop 2 related to animal welfare in 2008).  Bovay and Alston found the following:

Projections using our estimated model imply that a majority of voters in only three of fifty states (Hawaii, Rhode Island, and Vermont) plus the District of Columbia would have passed Proposition 37 had it been on their ballots in 2012