How Votes on GMO Labeling Change Concern for GMOs

At the annual meetings of the Agricultural and Applied Economics Association last week in Chicago, I saw an interesting presentation by Jane Kolodinsky from the University of Vermont.  She utilized some survey data collected in Vermont before and after mandatory labels on GMOs appeared on products in that state to determine whether consumers seeing GMO labels on the shelf led to greater or lower support for GMOs as measured by her surveys.  

I'm not sure if she's ready to make those results public yet, so I won't discuss her findings here (I will note I'm now working with her now to combine some of my survey data with hers to see whether the findings hold up in a larger sample).

Nonetheless, her presentation led me think about some of the survey data I collected over the years as a part of the Food Demand Survey (FooDS) project.  While I don't have enough data from consumers in Vermont to ask the same question Jane did, I do have quite a bit of data from the larger states of Oregon and Colorado, which held public votes on mandatory labeling for GMOs back in December 2014.  

In particular, I can ask the question: did the publicity surrounding the vote initiative on mandatory GMO labeling cause people to become more or less concerned about GMOs in general?

We have some strong anecdotal evidence to suggest that support for GMO labeling fell pretty dramatically in the months leading up to the vote.  For example, here are the results from several polls in California (including one data point my research with Brandon McFadden generated) on support/opposition to mandatory GMO labeling.  The figure below shows support for the policy was high but fell precipitously as the election campaigning began, and as we all know by now, the policy ultimately failed to garner majority support in California.

There is a similar pattern of support for mandatory GMO labeling in other states where the voter initiatives were held.  However, just because public support for a mandatory labeling policy fell as a result of campaign ads, this doesn't necessarily mean people thought GMOs were safer or more acceptable per se.  Indeed, many of the negative campaign ads focused on possible "paydays for lawyers" or inconsistencies in the ways the laws would be implemented, rather than focusing on the underlying technology itself.  

The Food Demand Survey has been conducted nationwide and monthly since May of 2013.  In November of 2014, two states - Colorado and Oregon - held widely publicized votes on mandatory GMO labeling.  These data can be used to calculate a difference-in-difference estimate of the effect of mandatory GMO labeling vote on awareness of GMOs in the news and concern about GMOs as a food safety risk.

The survey asks all respondents, every month, two questions of relevance here.  First, “Overall, how much have you heard or read about each of the following topics in the past two weeks” with response categories: 1=nothing; 2=a little; 3=a moderate amount; 4=quite a bit; 5=a great deal.  Second, we also ask, “How concerned are you that the following pose a health hazard in the food that you eat in the next two weeks” with response categories: 1=very unconcerned; 2= somewhat unconcerned; 3=neither concerned nor unconcerned; 4=somewhat concerned; 5=very concerned.  One of the 16 issues we ask about is "genetically modified food."

These data allow us to calculate a so-called difference-in-difference estimate.  That is - were people in CA and OR more concerned about GMOs than people in the rest of the country (this is the first difference) and how did this gap change during and after all the publicity surrounding the vote (this is the second and third difference)?  The "treated" group are the people in CA and OR while the "control" group consists of people in all other US states.

To analyze these question, I split the data into three time periods - "before" the vote (the months prior to September 2014), during the vote (Sep, Oct, Nov, Dec of 2014 and Jan of 2015) and after the vote (all the months after January 2015).  There were 485 "treated" people in CO and OR before the vote, 172 in these locations during, and 908 in these locations after (out of a total sample size of almost 49,000). 

In terms of awareness, here's what I found. 

Compared to people other parts of the U.S., people in CO and OR indeed reported hearing more about GMOs in the news during the ballot initiative vote than they did before and after (the increase in news awareness during the months surround the vote was statistically significant at the 0.01 level).

But, here's the key question.  Did the vote increase or decrease concern about GMOs as a food safety risk?  Apparently there was no effect.  The graph below shows, as compared to people in other states where there were no votes, there was actually a small increase in concern for GMOs in CO and OR in the months during the vote (however, the increase was not statistically significant, p=0.36), which then fell back down to pre-vote levels after the vote.  

So, despite evidence that the vote initiative on mandatory labeling led to an increase in awareness of GMOs in the news, it did not substantively affect concern about GMOs one way or the other.

Fights over Pigweed

None of this will be new to the farmers out there (indeed, there is already an ongoing lawsuit), but this episode of NPR's Planet Money podcast covers a problem that can arise when one farmer's pesticide winds up killing another farmer's crops.  Here's a summary of the story:

Farmers are in constant conflict with the weed. Some have turned to a powerful pesticide called Dicamba. Dicamba kills the pigweed, but it also kills the neighbors’ plants, including farmer Mike Wallace’s crops. The conflict was no longer farmer versus weed, but also farmer versus farmer. When his neighbors illegally sprayed the pesticide, Wallace reported it. After harvest, Wallace was shot and killed.

The story is a powerful lesson about externalities that can arise with herbicide resistant genetically engineered crops (this one is largely negative, but note that GE Bt crops can create positive externalities). Who's to blame in this case?  Monsanto for releasing GE Dicamba-resistant seed before a new version of Dicamba was released? Regulators for their slowness in approving the new Dicamba? Farmers who improperly used and applied the old version of Dicamba?  You'll have to listen and form your own judgement.    

Changes in consumer perceptions of GMOs over time

A new article by Kristin Runge et al. in the journal Public Opinion Quarterly pulls together polling results over the past few decades in an attempt to ascertain changes in public opinion about biotechnology and GMOs.  Here's the abstract.

Over the past 50 years, the food industry has transformed. The first food-related crops containing gene modifications were commercialized in the late 1990s, and researchers began documenting trends toward consumption of larger portions of food, increased reliance on fast food, and the health impacts of living in “food deserts.” Polls examined here document a general, though not monotonic, decline in confidence that the federal government can ensure the safety of the food supply, a similar decline in confidence that food in restaurants or grocery stores is safe to eat, a decline in the belief that packaged-food companies are doing a good job, and an increased sensitivity to the negative aspects of GMO foods. At the same time, we find that fewer people are attending to biotechnology-related news or the information on food packaging, but increasingly attending to food warnings and nutritional recommendations.

It is an interesting article focusing on more than just biotechnology, but misses some of the other attempts to aggregate polling results on these issues over the years from, for examples, Pew and IFIC.  Also, one shouldn't discount the many meta analyses that have been done on this topic relying on the academic literature (e.g., here, here, or here), which doesn't show much trend toward increasing concern about biotechnology or GMOs.  The results from my Food Demand Survey (FooDS) also shows very little evidence of changes in awareness or concern about GMOs over the past four years.  

FDA's New Effort to Educate about GMOs

AgriPulse recently ran an article about a new Congressionally mandated effort to educate consumers about biotechnology.  According to the article:

The fiscal 2017 spending bill enacted at the end of April includes $3 million earmarked for the FDA to coordinate with the Agriculture Department on a consumer outreach and education effort. The stated goal under the legislation is to educate consumers “on the environmental, nutritional, food safety, economic, and humanitarian impacts of such biotechnology, foodstuffs, and feed.”

The article includes several quotes from yours truly.  I was asked whether the spending will make any real difference with consumer attitudes based and whether the effort could harm FDA’s credibility as a regulator.  Here is the (slightly edited) responses I gave to the article's author.  

On the second question: can information affect public perceptions?  The answer is yes - at least a bit.  Most of our research shows consumers remain highly uniform (and often misinformed) about the technology.  As a result, subtle changes in wording, descriptions of benefits of the technology, etc. can be persuasive.  I think this can be seen most directly in the various state ballot initiatives on mandatory GE labeling.  Early polling in all the states showed that voters approved of the laws by a wide margin.  But as the vote neared and biotech companies and others started running ads, support eroded to such a point that the mandatory GE labeling laws failed in every state where they were put on the ballot.  This is fairly strong evidence that information mattered in the "real world."  That said, the USDA and FDA have communicated on these issues in the past, and it is unclear what effects they had.  

All this suggests that the form of the communication matters.  Information that is scientifically accurate but focused on the perspective of the farmers/consumers who benefit is likely to be most persuasive.

Could credibility be harmed?  Well, I don't believe the government should promote a particular company or industry per se (though of course it already does that in a variety of direct and indirect ways such as encouraging conversion to organic, facilitating labeling programs and marketing orders, etc), but providing the public with accurate, scientific information on matters of public concern seems a legitimate role for government.  Focusing on the wide range of applications in the private, public, and nonprofit sectors is one way of perhaps avoiding perceptions of impropriety.  Also being honest about possible downsides and trade-offs is important. Also, not overselling - biotech is a tool but it's not a universal savior.

Solar Radiation and Crop Yields

My last post discussed some recent research we conducted on the impacts of biotechnology adoption on corn yields.  A reader forwarded a link to a recent paper in the journal Nature Climate Change raising an issue I hadn't yet heard about.  Using some simulations, the authors argue that increased solar radiation, which led to brighter skies, has had a big impact on recent increases in corn yields.  

Here's the abstract:

Predictions of crop yield under future climate change are predicated on historical yield trends, hence it is important to identify the contributors to historical yield gains and their potential for continued increase. The large gains in maize yield in the US Corn Belt have been attributed to agricultural technologies, ignoring the potential contribution of solar brightening (decadal-scale increases in incident solar radiation) reported for much of the globe since the mid-1980s. In this study, using a novel biophysical/empirical approach, we show that solar brightening contributed approximately 27% of the US Corn Belt yield trend from 1984 to 2013. Accumulated solar brightening during the post-flowering phase of development of maize increased during the past three decades, causing the yield increase that previously had been attributed to agricultural technology. Several factors are believed to cause solar brightening, but their relative importance and future outlook are unknown, making prediction of continued solar brightening and its future contribution to yield gain uncertain. Consequently, results of this study call into question the implicit use of historical yield trends in predicting yields under future climate change scenarios.

I don't know enough about the issue to speak to the credibility of the authors' findings.  However, I not sure that this is much of a confound for our study on biotech adoption because our estimated effects are (partially) identified by using variation in yields across states that have differential adoption rates (and yet are presumably exposed to the same solar radiation).  To the extent that identification our effects of biotech adoption come about from comparisons of yields in the same counties over time (where solar radiation varied over time), this could be an issue, but again, the time trend included in our models should pick up this effect as well.