Herbicide Resistance and GE Crops - Thinking like an economist

In a recent issue of Weed Science, Andrew Kniss investigates the relationship between herbicide resistance in weeds and adoption of genetically engineered crops.

There is a popular story with an anti-gmo theme that holds that genetically modified crops tolerant to roundup (glyphosate) herbicide have encouraged excessive levels of use. This has lead to a build up of roundup resistant weeds. In some sense, this paper may provide some evidence in favor of that story. However, I think there is a tendency among critics to extrapolate further that GMOs lead to higher levels of weed resistance (in general). The storyline does not make a distinction between weed resistance in general and specific resistance to roundup.

What this paper does indicate is that there are to some degree externality mitigating aspects of glyphosate tolerant crops. (not exactly but somewhat like the positive externalities we have seen with Bt crops). As stated in the abstract, "Increased glyphosate use in cotton and soybean largely displaced herbicides that are more likely to select for herbicide-resistant weeds, which at least partially mitigated the impact of reduced herbicide diversity....the evolution of new glyphosate-resistant weed species as a function of area sprayed has remained relatively low compared with several other commonly used herbicide SOAs."

This paper definitely provides data and evidence contrary to some of the popular stories condemning biotechnology. Stories that don't look at crop production from a more comprehensive systems based viewpoint miss these nuances. Hmmm....it appears that thinking like an economist (systematically considering intended and unintended consequences) has a lot to lend to the nuances of herbicide resistance.

More from the Abstract:

 "adoption of GE corn varieties did not reduce herbicide diversity, and therefore likely did not increase selection pressure for herbicide-resistant weeds in that crop. Adoption of GE herbicide-resistant varieties substantially reduced herbicide diversity in cotton and soybean. Increased glyphosate use in cotton and soybean largely displaced herbicides that are more likely to select for herbicide-resistant weeds, which at least partially mitigated the impact of reduced herbicide diversity. The overall rate of newly confirmed herbicide-resistant weed species to all herbicide sites of action (SOAs) has slowed in the United States since 2005. Although the number of glyphosate-resistant weeds has increased since 1998, the evolution of new glyphosate-resistant weed species as a function of area sprayed has remained relatively low compared with several other commonly used herbicide SOAs."

Link and Citation:

Kniss, A. (2017). Genetically Engineered Herbicide-Resistant Crops and Herbicide-Resistant Weed Evolution in the United States. Weed Science, 1-14. doi:10.1017/wsc.2017.70

https://www.cambridge.org/core/journals/weed-science/article/genetically-engineered-herbicideresistant-crops-and-herbicideresistant-weed-evolution-in-the-united-states/22B3B07F8EB980D2CFEEE3AA36B7B2C1

See also: 
Game Theoretic Analysis of Bt Resistance
Positive Externalities of Biotech Bt Traits on Non-Biotech Crops and Non Target Insects
Environmental and Health Effects of Bt Cotton
Choices Magazine - Herbicide Resistance

Environmental and Health Effects of Bt Cotton

Kouser, S., Qaim, M., Impact of Bt cotton on pesticide poisoning in smallholder agriculture: A panel data analysis,Ecol. Econ. (2011), doi:10.1016/j.ecolecon.2011.06.008

"While substantial research on the productivity and profit effects of Bt cotton has been carried out recently, the economic evaluation of positive and negative externalities has received much less attention. Here, we focus on farmer health impacts resulting from Bt-related changes in chemical pesticide use. Previous studies have documented that Bt cotton has reduced the problem of pesticide poisoning in developing countries, but they have failed to account for unobserved heterogeneity between technology adopters and non-adopters. We use unique panel survey data from India to estimate unbiased effects and their developments over time. Bt cotton has reduced pesticide applications by 50%, with the largest reductions of 70% occurring in the most toxic types of chemicals. Results of fixed-effects Poisson models confirm that Bt has notably reduced the incidence of acute pesticide poisoning among cotton growers. These effects have become more pronounced with increasing technology adoption rates. Bt cotton now helps to avoid several million cases of pesticide poisoning in India every year, which also entails sizeable health cost savings." 

The Challenging Tradeoff of Weighing Biased Consumer Preferences Against Marketing Food with Integrity

Recently I was reading an artcile, "The big Washington food fight" in Politico discussing challenges facing bringing diverse interests and perspectives on food issues under one roof through the Grocery Manufacturers association.

There are a couple things influencing my thinking about this.....the idea that voters and consumers may have systemic biases in their knowledge and preferences in general and specifically about food and technology. The other thing is  related to recent research showing a divergence between public perception of science driven by political leaning....a divergence that widens *with* more education and science knowledge (see http://www.pnas.org/content/114/36/9587 ).

This research was not directly related to food except for genetically engineered food . Biotech related effects were not significant in this paper, but as the article noted the data is from 2006 and perhaps biotech was not nearly as politicized or polarized as it would be reflected in more recent data.

So in this context, what does it mean to say 'the customer is always right' and how do you give the customer what they want?

For instance, sustainable food seems to be high on the list of priorities. However, there are plenty of cases where the most sustainable technology is completely rejected by some segments. I'm thinking here of rBST, various aspects of biotechnology, even processing mechanics like finely textured beef. These are all examples where scientifically, you can produce more food using fewer resources and have a lower carbon footprint.

There seem to be two dominant approaches or paradigms by food companies for dealing with this.

One approach is going all in with the 'negative' or 'free from' labeling regardless of science. This paradigm feigns or fakes transparency in the sense it acknowledges consumer preferences related to knowing 'what is in their food' but adds lots of confusion about substantial differences related to food safety and sustainability. This group is more likely to engage in negative advertising (think Chipotle) and lobbying for regulations related to food labeling requirements (think Vermont). The other paradigm takes a 'less is more' approach in terms of honest disclosure about these technologies.

Production agriculture is caught in the middle. Whichever paradigm becomes the most dominant (both in the marketplace and the ballot box) I fear will determine the fate of the kinds of crops farmers grow and technologies they have access too, types of products we see on the shelves, and the potential for healthier and more environmentally sustainable solutions to challenging worldwide problems.

See also: Food with Integrity is Catching On