How do people respond to scientific information about GMOs and climate change?

The journal Food Policy just published a paper by Brandon McFadden and me that explores how consumers respond to scientific information about genetically engineered foods and about climate change.  The paper was motivated by some previous work we'd done where we found that people didn't always respond as anticipated to television advertisements encouraging them to vote for or against mandatory labels on GMOs.  

In this study, respondents were shown a collection of statements from authoritative scientific bodies (like the National Academies of Science and United Nations) about the safety of eating approved GMOs or the risk of climate change.  Then we asked respondents whether they were more or less likely to believe GMOs were safe to eat or whether the earth was warming more than it would have otherwise due to human activities.    

We classified people as "conservative" (if they stuck with their prior beliefs regardless of the information), "convergent" (if they changed their beliefs in a way consistent with the scientific information), or "divergent" (if they changed their beliefs in a way inconsistent with the scientific information). 

We then explored the factors that explained how people responded to the information.  As it turns out, one of the most important factors determining how you respond to information is your prior belief.  If your priors were that GMOs were safe to eat and that global warming was occurring, you were more likely to find the information credible and respond in a "rational" (or Bayesian updating) way.  

Here are a couple graphs from the paper illustrating that result (where believers already tended to believe the information contained in the scientific statements and deniers did not).  As the results below show, the "deniers" were more likely to be "divergent" - that is, the provision scientific information caused them to be more likely to believe the opposite of the message conveyed in the scientific information.  

We also explored a host of other psychological factors that influenced how people responded to scientific information.  Here's the abstract:

“The ability of scientific knowledge to contribute to public debate about societal risks depends on how the public assimilates information resulting from the scientific community. Bayesian decision theory assumes that people update a belief by allocating weights to a prior belief and new information to form a posterior belief. The purpose of this study was to determine the effects of prior beliefs on assimilation of scientific information and test several hypotheses about the manner in which people process scientific information on genetically modified food and global warming. Results indicated that assimilation of information is dependent on prior beliefs and that the failure to converge a posterior belief to information is a result of several factors including: misinterpreting information, illusionary correlations, selectively scrutinizing information, information-processing problems, knowledge, political affiliation, and cognitive function.”

An excerpt from the conclusions:

“Participants who misinterpreted the information provided did not converge posterior beliefs to the information. Rabin and Schrag (1999) asserted that people suffering from confirmation bias misinterpret evidence to conform to a prior belief. The results here confirmed that people who misinterpreted information did indeed exhibit confirmation, as well as people who conserved a prior belief. This is more evidence that assuming optimal Bayesian updating may only be appropriate when new information is somewhat aligned with a prior belief.”

A comedian's take on contract poultry farming

On the HBO show Last Week Tonight, comedian John Oliver (formerly with the Daily Show on Comedy Central) weights in on the issue of contract poultry farming.  His piece is a take-off of the themes in Christopher Leonard's book, The Meat Racket (which I critically reviewed here).  

Here's the episode, which already seems to be garnering quite a bit of attention. 

Are consumers really spending more on food away from home?

A couple days ago, the Wall Street Journal ran a story that started as follows

“Retail-sales figures released by the U.S. Commerce Department garnered considerable attention last month when news reports suggested they showed Americans spent more money dining out than buying groceries for the first time ever.

Some observers jumped from there and attributed the shift to the growing clout of millennials, saying they prefer breaking bread with friends at restaurants, while sad-sack baby boomers who didn’t save enough for retirement are stuck cooking at home.

But as it turns out, reports on the decline of home cooking were half baked. They demonstrate, once again, that it is important to understand how the government compiles statistics to avoid jumping to conclusions the figures don’t support.”

I agree.

As the story points out, the government's data ignores sales from some major grocery establishments like Wal-Mart.

This is an issue we've been tracking in the Food Demand Survey (FooDS) for over two years now.  Our data from a nationally representative sample of consumers show it's not even close.   People spend a lot more money on food at home.  Here's the data from our second annual report.

Our most recent release, just a couple days ago shows at home consumption at about $96/week and away from home at about $53/week.  

Thus, our data clearly supports the conclusion drawn by Jo Craven McGinty in the WSJ:

“The government’s monthly retail-sales report provides valuable information that reveals legitimate trends, providing users understand what the numbers represent.

In this case, no matter how you slice it, spending on dining out hasn’t surpassed spending on groceries”

Does Subsidized Crop Insurance Encourage Farmers to Take Risk?

“This paper devises a tractable empirical framework to examine whether the highly subsidized crop insurance program by the United States government makes farmers more sensitive to changes in extreme heat and thereby limits their ability to cope with extreme heat or adapt to it. Insured farmers might not engage in the optimal protection against harmful extreme heat as the resulting crop losses are covered by the insurance program. . . Our results suggest a significant amount of moral hazard in federal crop insurance. ”

That's from a paper by Francis Annan and Wolfram Schlenker  just released in the American Economic Review proceedings issue.  The authors go on to write:

“This has important implications: first, since the federal government encourages participation in the crop insurance program through premium subsidies, the presence of moral hazard implies that there will be additional cost to the program as losses exceed what they could have been without the program. Second, climate change will amplify the government induced distortion as it will increase the frequency of extremely hot temperatures. Third, our findings imply that there are possibilities to adapt to climate change as uninsured areas show lower sensitivities, but this adaptation potential is skewed by government programs that give a disincentive to engage in it. A farmer will choose subsidized yield guarantees over costly adaptation measures.”

Food Demand Survey - May 2015

The results of the May 2015 edition of the Food Demand Survey (FooDS) are now in.

Results reveal mixed changes in willingness-to-pay for disaggregate meat products.  However, stated purchase intentions for beef, pork, and chicken were all higher than last month as were expectations of price increases, suggesting an uptick in demand for meat.

As was the case in April, this month we again noticed an uptick in awareness of news about bird flu and an increase in concern about the issue.  That's two months in a row of notable increases in this issue.

We added several new ad hoc questions to the survey this month.  

The first set of questions were in response to the spreading avian influenza (bird flu) problem.  I've had several media inquiries (probably in response to this post) about the potential economic impacts of the outbreak.  One questions is whether domestic consumer demand for poultry and eggs will dampen in response to the outbreak.  My understanding is that avian influenza does not pose a human health or food safety risk, but of course that doesn't mean consumers believe the same.  As the regular tracking questions mentioned above suggest, consumers are becoming aware of the issue.  To delve into it a bit more, we added two agree/disagree questions. 

About 23% of respondents agreed or strongly agreed that they plan to eat less turkey and eggs because of the outbreak of avian influenza, and another 32% say they're concerned about the turkey and eggs they eat.  That's far from a majority, but it might be a large enough to affect demand.  Whether these beliefs will ultimately manifest themselves in the supermarket remains to be seen.  

A second set of questions were added to delve a bit deeper into the issue of labeling of GMO foods.  Yes, this an issue that has been much studied, and yes, consumer's answers to the question can't entirely be taken at face value (as my questions on preferences for DNA labeling have shown).  But, there seems to be some activity related to a GMO federal labeling initiative re-introduced by US Congressman Mike Pompeo from Kansas and others (see this for some discussion and background).  The bill has food industry support and it would move authority for GMO labeling to the FDA (and away from the states) and would only require labels if the FDA determines a health or safety risk.   

The first question asked: “Which of the following best describes your position on labeling of genetically engineered food?” Over half of the respondents answered, “Food companies should be required to label genetically engineered food in all circumstances”.  The other 46% of respondents expressed a more nuanced view.  About one fifth thought labeling should only be required if there is a health or safety risk and another 18% did not have a strong position. The remaining 6.5% of respondents stated “In general, food companies should not be required to label genetically engineered food but voluntary labels are permitted”.

Secondly, participants were asked: “How should the issue of mandatory labeling of genetically engineered food be decided?”  They could choose from one of six options.  

The majority, 61%, of the respondents stated “by the U.S. Food and Drug Administration (FDA)”.  Just over 10% of repspondents stated “I don’t know” and only 5% of respondents stated “by ballot initiatives in each state”.

Finally, the third question asked: “To what extent do you agree or disagree with each of the following statements?”  Participants were asked to rate each statement on a scale of 1 to 5 where 1 = strongly disagree, 3=neither agree nor disagree, and 5 = strongly agree.

Respondents rated the statement “In general, I support mandatory labeling or genetically engineered foods” the highest out of the nine statements with a score of 3.86.  The statement “Seeing a label indicating the presence of genetically engineered ingredients on a food product would increase the likelihood I’d buy the product” rated the the lowest of the nine statements with a score of 2.84. 

Thanks to David Ropeik who suggested a couple of the questions below related to effect of labels on perceptions on choice.