Are pesticides causing farmer depression or just the pests?

An article in Modern Farmer says (HT Bailey Norwood):

“Earlier this fall, researchers from the National Institute of Health finished up a landmark 20-year study, a study that hasn’t received the amount of coverage it deserves. About 84,000 farmers and spouses of farmers were interviewed since the mid-1990s to investigate the connection between pesticides and depression, a connection that had been suggested through anecdotal evidence for far longer. ”

It could be that something in the chemical make-up of the pesticide leads to increased depression among farmers, and the article itself speculates about nerve disorders caused by pesticides.  

But, isn't it also possible that farmers are depressed when their crops are attacked by pests (which coincides with the application of pesticides)? Isn't also possible that farmers don't like having to pay unexpected bills to protect their harvest from invading pests?  This budget from University of Illinois suggests that about 15% of the direct costs of growing corn (about $60 to$66/acre) go toward pesticides.  That's the expected cost.  Now imagine the cost of an unexpected infestation.  Makes me depressed just thinking about it.

None of that is to make light of depression among farmers.  But, as the original story revealed, rates of depression among farmers is lower than for the general population.  It will take more than these types of correlations in observational data to indicate whether it is the pests or the pesticides causing depression.

Effects of Citrus Greening

Writing in Choices magazine, several agricultural economists discuss the impact of a virus that has adversely affected Florida citrus growers and the nation's citrus consumers.

“Huanglongbing (HLB), also known as citrus greening, has emerged as an increasing threat to the economic viability of citrus production in Florida. Citrus greening was first observed in non-commercial, backyard citrus in South Florida in August 2005. By February 2009, citrus greening had spread throughout the traditional citrus areas of the state. Thus far, quarantine, tree removal, insecticide applications, heat treatments, and foliar nutritional techniques designed to mask the disease symptoms are the only available, but not completely effective, techniques for managing citrus greening. The disease directly affects the citrus tree resulting in reduced yield and fruit quality following an initial incubation period, eventually making the tree unproductive and contributing to greater mortality.”

The impacts?

“consumers would be expected to lose $154.9 million due to higher prices and less consumption. Despite higher prices, producers would be expected to lose $18.09 million because the decrease in sales would outweigh the increase in price received. Hence, the total economic cost of greening is estimated to be $173.0 million. However, these estimates may understate the economic cost of citrus greening ”

What's being done?

“To solve these problems, researchers are putting tremendous time and effort into finding solutions to HLB. The U.S. Department of Agriculture has allocated $24 million for fiscal year 2014 specifically for citrus disease research. The money is allocated to researchers through a competitive grant process under the Specialty Crop Research Initiative/Citrus Disease Research and Extension program. Proposed projects from researchers at many institutions include developing and testing compounds to cure the disease itself, developing and testing improved insecticide programs to increase efficacy and reduce resistance development, and developing and testing alternative psyllid controls such as the use of biological options. Other possible solutions include genetically modifying citrus trees to be resistant to the disease or genetically modifying psyllids to be incapable of vectoring the disease. Thus, substantial time and effort have been allocated to finding solutions to the problem, but most possible solutions will take time to develop and test before growers will be able to benefit from them.”

An interview on GMO labeling initiatives

Here's an interview I did with the University of Nebraska's Market Journal on the outcomes of the most recent ballot initiatives on GMO labeling.

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.