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What are the farm-level effects of GMOs?

A new study published in PLoS ONE by Wilhelm Klümper and Matin Qaim surveyed the literature on the farm-level effects of GMO adoption.  They conducted a Meta analysis - a type of quantitative literature review - covering 147 previous studies.

What did they find?

“On average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.”

This is a a decent study which summarizes what most people who follow the literature already know.  There will, no doubt, be attempts by the anti-GMO crowd to discredit the study.  However, Qaim is a productive, well known agricultural economist.  He’s published in the best outlets in agricultural and development economics, and even in journals like Science and Nature Biotechnology.  

Like any Meta analysis, the study isn't perfect, and is only as good as the studies being reviewed.  A few criticisms.  The analysis didn't much differentiate between insecticides (the use of which has almost certainly fallen) and herbicides (total use is probably up, but because GM producers have switched to less toxic herbicides  the total toxicity is likely down).  Also, some of the underlying studies may not have done a good job separating yield gains from traditional hybrid breeding from gains conveyed by biotechnology per se, so the yield gains attributable to GM may be a bit overstated (e.g., see this study).  What I’m saying here is that corn/soybean yields probably would have increased regardless of whether GM was adopted, so you have to “back out” the increase attributable to GM; some studies do that well, others don’t.  Finally, as you can see in their figures, there is a lot of heterogeneity across studies; the mean effects for yields and profit are positive, but some studies show negative.  

In any event, this is a good study that re-confirms my own reading of the literature.

GMO and Soda Votes

I have been keeping an eye on several ballot initiatives in yesterday's election.  Not all results are finalized, but here's what we know so far:

In Colorado, mandatory GMO labeling was defeated by a wide margin, 66% to 34%, with 93% of precincts reporting.

In Oregon, mandatory GMO labeling is very close and still up in the air.  With 88% of the votes counted, the "No's" are ahead by about 26,000 votes (659,404 to 633,132), giving the "No's" a current 51% to 49% margin. 

A vote in Maui, HI to ban cultivation of GMOs is too close to call

Berkeley, CA passed a soda tax (75% in favor vs. 25% opposed)

The majority of voters in San Francisco, CA favored a soda tax (55% in favor), but the initiative required a 2/3 majority to pass. Thus, the soda tax failed in San Francisco.  

Why haven't GMOs lived up to their promise?

“next time you hear someone say GMOs haven’t lived up to their potential, much less contribute to food security, remember the biotech crops and foods that never made it to market, and how Kimbrell [the founder and executive director of the Center for Food Safety, which for years has spearheaded opposition to biotechnology] and his fellow anti-GMO activists proudly take ownership of that.”

The evidence?  The anti-GMO activist presents it himself at a recent anti-technology conference in New York:

““We stopped GMO potatoes, we stopped GMO wheat, we stopped genetically modified rice, and we stopped genetically modified salmon,” he said. (The last one has been in regulatory limbo for over a decade.) It’s impossible to quantify how much credit biotech opponents should receive for the failed commercialization of the aforementioned GMOs.”

Anti-biotechnology activists complain biotechnology hasn't lived up to its promise all the while fighting the approval of the most promising biotechnologies.

Gluten fad

Michael Specter has written for the New Yorker what is easily the the best article I've read to date on the gluten-free fad:

He writes

“The fear of gluten has become so pronounced that, a few weeks ago, the television show “South Park” devoted an episode to the issue. South Park became the first entirely gluten-free town in the nation. Federal agents placed anyone suspected of having been “contaminated” in quarantine at a Papa John’s surrounded by razor wire. Citizens were forced to strip their cupboards of offending foods, and an angry mob took a flamethrower to the wheat fields.

“No matter what kind of sickness has taken hold of you, let’s blame gluten,’’ April Peveteaux writes in her highly entertaining book “Gluten Is My Bitch.” ”

and

“Joseph A. Murray, a professor of medicine at the Mayo Clinic and the president of the North American Society for the Study of Celiac Disease, has also studied wheat genetics. He agrees with Kasarda. “The wheat grain is not a lot different than it was fifty years ago,’’ Murray told me. “Chemically, the contents just have not changed much. And there is something more important to note. Wheat consumption is going down, not up. I don’t think this is a problem that can be linked to the genetics of wheat.””

and

“While there are no scientific data to demonstrate that millions of people have become allergic or intolerant to gluten (or to other wheat proteins), there is convincing and repeated evidence that dietary self-diagnoses are almost always wrong, particularly when the diagnosis extends to most of society”

The article does go on to speculate a bit about why some people lose weight when going on "gluten free" diets and why the rate of Celiac disease has risen to about 1% of the population.  Well worth reading.