Do Scientists Mislead?

"Yes" seems to be the unfortunate conclusion that stems from this paper by Mark Cope and David Allison published in the International Journal of Obesity.  ​Scientists may not (or may) distort their own research findings, but Cope and Allison show, pretty convulsively, that there is a general pattern of distorting the findings of others.   

They attribute this to a "white hat bias":​

which we define to be bias leading to distortion of research-based information in the service of what may be perceived as righteous ends.

Cope and Allison found two studies related to soda consumption that:

had both statistically and non-statistically significant results on body-weight, body mass index (BMI) or overweight/obesity status which allowed future writers to potentially choose which results to cite, and were also widely cited, permitting quantitative analysis of citations.

​Then, they looked at how other scientists subsequently cited the findings in their published papers.  Did they focus on the negative findings (that soda doesn't affect weight, etc.) or the positive findings (that soda does affect weight, etc.): ​

The majority, 84.3% for [2] and 66.7% for [3], described results in a misleadingly positive way to varying degrees (i.e., exaggerating the strength of the evidence that [nutritively-sweetened beverage] reduction showed beneficial effects on obesity outcomes). Some were blatantly factually incorrect in their misleading statements, describing the result as showing an effect for a continuous obesity outcome whereas no statistically significant effect for continuous obesity outcomes was observed. In contrast, only four papers (3.5%) were negatively misleading (i.e., underplayed the strength of evidence) for [2] and none were negatively misleading for [3]. Only 12.7% and 33% of the papers accurately described complete overall findings related to obesity outcomes from [2] and [3], respectively.

​

They went on to document a similar pattern for studies on the effects of breastfeeding. They ​conclude:

Evidence presented herein suggests that at least one thing has been demonized ([nutritively-sweetened beverage] consumption) and another sanctified (Breastfeeding), leading to bias in the presentation of research literature to other scientists and to the public at large, a bias sufficient to misguide readers. Interestingly, while many papers point out what appear to be biases resulting from industry funding, we have identified here, perhaps for the first time, clear evidence that white-hat biases can also exist in opposition to industry interests.

Assorted Links

• Horse slaughter is back

• ​Park Wilde reviews the book Salt, Sugar Fat

• ​Another reason to be leery of local food (beware the backyard chicken)

• Does switching from whole to skim milk increase obesity in children? (I'm stunned that this story (or the people interviewed) ​didn't note that parents of over-weight children are more likely to give their kids skim - the direction of causation is running the other way around).

• Organic labels bias taste perceptions (and perceptions of caloric content)

• Oklahoma one of the freest states?

Monsanto Protection Act

There seems to be quite a fervor on the "foodie" web sites about ​a provision included in the continuing resolution bill that was recently signed by the President.  It has been dubbed the "Monsanto Protection Act."  For just a couple examples - see here or here - or Food Democracy Now, which seems to be among the most upset.

I wanted to see what the provision actually said, so I looked it up.  If I'm not mistaken, here (or here) is the text of the provision (see section 735)​:

Sec. 735. In the event that a determination of non-regulated status made pursuant to section 411 of the Plant Protection Act is or has been invalidated or vacated, the Secretary of Agriculture shall, notwithstanding any other provision of law, upon request by a farmer, grower, farm operator, or producer, immediately grant temporary permit(s) or temporary deregulation in part, subject to necessary and appropriate conditions consistent with section 411(a) or 412(c) of the Plant Protection Act, which interim conditions shall authorize the movement, introduction, continued cultivation, commercialization and other specifically enumerated activities and requirements, including measures designed to mitigate or minimize potential adverse environmental effects, if any, relevant to the Secretary’s evaluation of the petition for non-regulated status, while ensuring that growers or other users are able to move, plant, cultivate, introduce into commerce and carry out other authorized activities in a timely manner: Provided, That all such conditions shall be applicable only for the interim period necessary for the Secretary to complete any required analyses or consultations related to the petition for non-regulated status: Provided further, That nothing in this section shall be construed as limiting the Secretary’s authority under section 411, 412 and 414 of the Plant Protection Act.

​

I'm going to have to go to law school to figure out exactly what that means.  Here is an interpretation, according to one source, by those against biotechnology:​

According to Dave Murphy, Founder and Executive Director of FoodDemocracyNow.com, the twisted language of Section 735, “authorizes the Secretary to basically allow plantings of new GMO at anytime when a court case is taking place.” 

Perhaps, although it does seem that the Secretary is required to "complete any required analysis or consultations related to the petition for non-regulated status."  Some in the ag press seem to indicate that the provision is designed to protect farmers because it:

requires that USDA allow farmers to continue growing biotech crops that USDA deregulated, but a judge later invalidated.

Honestly, I don't understand the language of the provision (or the consequences of it) well enough to offer any intelligible thoughts.  ​

I did think what Darren Hudson, an agricultural economics professor at Texas Tech University and anything but an anti-biotech crusader, had to say about the issue was interesting.  

Do I think bio-tech firms are angelic do-gooders?  No.  Do I believe they are purposely misleading consumers about health risks?  I have seen no evidence that they are (not that there are no risks; I have just seen no compelling evidence that those risks outweigh any benefits).  But, the problem is that by preemptively exempting Monsanto from any future litigation, you have effectively given them a blank pass, which could lead them to act more recklessly than they otherwise would.  Will they?  I don't know.  But, as an economist, all I can do is look at the incentives and in this case, I am not sure the benefits to society outweigh the potential costs.  This, in my opinion, was simply bad policy.

​Addendum:

I just ran across this very sensible article by David Bier which puts a lot of the paranoia over the provision in perspective.  Here is one small bit:​

The so-called “Monsanto Protection Act” actually does nothing to protect Monsanto. Rather, it protects the farmers that bought Monsanto seeds and planted them under the belief that it was legal to do so by granting them temporary permits for the existing crops in the ground, which have already been subjected to extensive USDA scrutiny. It does not allow them to keep planting even if there are proven health risks or to keep planting at all in fact. In other words, it has nothing to do with “consumer health concerns” or “stripping federal courts of the authority to halt the planting or sale of GMO seed crop” as the RT story claims. In fact, the sale of GE seeds would still be prohibited after a court finding.

The Monsanto Protection Act has nothing to do with consumer safety, limited liability, or as this ridiculous Salon.com article puts it, “protecting the biotech giant from litigation.” If GMOs actually injure your health, you are still entitled to sue. This effort is minor regulatory reform that was long overdue.

An Interview with Meatingplace

The latest issue of Meatingplace magazine features a cover with yours truly.  ​The inside (gated; but free to those who register) contains an interview I had with the editor and it mainly focuses on my book The Food Police, which comes out April 15.  

Here are a few excerpts from the interview:​

Meatingplace: Why did you decide to write "The Food Police" and whom are you hoping to reach?

LUSK: This book is for anyone who watches the Food Network, anyone who has read (Michael Pollan's) "The Omnivore's Dilemma" or watched "Food Inc." I wrote this book because I feel the state of food and agriculture is being distorted and there needs to be a voice out there countering a lot of what was being presented. I describe a lot of what's good about agriculture, and I describe a lot of the unintended consequences and sometimes outright craziness of policies that have been proposed.

and

Meatingplace: What is your view on the local food movement?

LUSK: I have a bit of a nuanced view. I fully support farmers markets and supporting local farmers. What I take issue with is this idea that somehow this activity in and of itself is virtuous and that it should be subsidized by farm-to-school programs. There are people like Michael Pollan who say we should have rules that schools and hospitals that receive public funding have to source a certain percentage of their food from a certain radius. I take issue with this sort of regulation of localism.

and

Meatingplace: What is your take on the politics of food regulations?

LUSK: We have a culture in which the consumer's first thought when there's a problem is to turn to the government rather than the people selling them the product. That's a problem.

A lot of politicians and a lot of the people we call the "food police" have good intentions. It's just that they don't think about the consequences or at least appreciate some of the unintended consequences. And they don't have the knowledge of the industry to know how these things are going to work out.

We all want safe food. We all want high-quality food. And I think part of what I'm trying to do by writing a book and other things is to try to help them understand that the market helps provide those things. 

There's quite a bit more in the magazine.​

Fat taxes may be even less effective than previously thought

An article that just appeared in the most recent issue of the American Journal of Agricultural Economics by Yuqing Zheng of RTI and Edward McLaughlin and Harry Kaiser of Cornell University presents some interesting thoughts regarding fat and soda taxes.

Most of the studies on fat and soda taxes use elasticities of demand to simulate the effectiveness of a tax.  The elasticity of demand tells us how responsive consumption of a product is to a change in it's price.  So, for example, an elasticity of demand of -0.6 would tell us that for every 1% increase in price, consumption would fall by 0.6%

Zheng and colleagues point out, however, that most people don't "see" the tax when they're shopping.  It only shows up on the bill when you check out.  As such, it is incorrect to directly use the price elasticity of demand  ​to infer how consumption of soda or fatty foods will change after a tax.  

They show that an excise tax (​which is levied on the supplier rather than the consumer) is probably more effective at reducing soda (or fat) consumption than a retail sales tax, but even excise taxes are likely to to be less effective at reducing consumption than an equivalent price increase.  

As a result, researchers need to adjust the demand elasticities before calculating the effects of a soda or fat tax (regardless of whether the tax is excise or retail).  Yet, almost no one does this.  The researchers show, however, that the required adjustment can be fairly dramatic.  In their "baseline" scenario, they show that the elasticity of demand needs to be reduced by a factor of 0.14.  So, if the elasticity of demand was -0.6, then we'd project a 1% increase in sales tax would only reduce consumption by 0.6*0.14 = 0.084%.  Instead, previous research on this topic has applied the original elasticity (e.g., 0.6) rather than the adjusted elasticity (e.g., 0.084).  Clearly, the adjusted elasticity will imply much lower effectiveness of the tax.

The authors conclude:​

Therefore, even a large increase in the sales tax rate on food and beverages will only reduce demand by a moderate degree.

and

our analysis of sales and excise taxes offers some explanation (e.g., imperfect tax knowledge, slow learning) on why the impact of sales tax is so difficult to detect, thus bridging the gap between the simulation studies and the empirical findings