Value of Nutritional Information

There is a general sense that nutritional information on food products is "good" and "valuable."  But, just how valuable is it?  Are the benefits greater than the costs?

There have been a large number of studies that have attempted to address this question and all have significant shortcomings.  Some studies just ask people survey questions about whether they use or look at labels.  Other studies have tried to look at how the addition of labels changes purchase behavior - but the focus here is typically limited to only a handful of products. As noted in an important early paper on this topic, by Mario Teisl, Nancy Bockstael, and Alan Levy, nutritional labels don't have to cause people to choose healthier foods to be valuable.  Here is one example they give:

“consider the individual who suffers from hypertension, has reduced his sodium intake according to medical advice, and believes his current sodium intake is satisfactory. If this individual were to learn that certain brands of popcorn were low in salt, then he may switch to these brands and allow himself more of some other high sodium food that he enjoys. Better nutritional information will cause changes in demand for products and increases in welfare even though it may not always cause a backwards shift in all risk increasing foods nor even a positive change in health status.”

This is why it is important to consider a large number of foods and food choices when trying to figure out the value of nutritional labels.  And that's exactly what we did in a new paper just published in the journal Food Policy.  One of my Ph.D. students, Jisung Jo, used some data from an experiment conducted by Laurent Muller and Bernard Ruffieux in France to estimate consumers' demands for 173 different food items in an environment where shoppers made an entire day's worth of food choices.  This lets us calculate the value of nutritional information per day (not just per product).  

The nutritional information we studied relies on two simple nutritional indices created by French researchers.  They are something akin to a NuVal label system or a traffic light system.  We first asked people where they thought each of the 173 foods fell on the nutritional indices (and we also asked how tasty or untasty each of the foods were), and then after making a day's worth of (non-hypothetical) food choices, we told them were each food actually fell.   Here's a bit more detail.  

“The initial “day 1” food choices were based on the individuals’ subjective (and implicit) health beliefs. Between days 1 and 2, we sought to measure those subjective health beliefs and also to provide objective information about each of the 173 foods. The beliefs were measured by asking respondents to pick the quadrant in the SAIN (Nutrient Adequacy Score for Individual foods) and LIM (for Limited Nutrient) table (Fig. 2) that best described where they thought each food fit. The SAIN and LIM are nutrient profiling models and indices introduced by the French Food Safety Agency. The SAIN score is a measure of “good” nutrients calculated as an un-weighted arithmetic mean of the percentage adequacy for five positive nutrients: protein, fiber, ascorbic acid, calcium, and iron. The LIM score is a measure of “bad” nutrients calculated as the mean percentage of the maximum recommended values for three nutrients: sodium, added sugar, and saturated fatty acid.2 Since indices help reduce search costs, displaying the information in the form of an index is a way to make the information available in an objective way but also allows consumers to better compare the many alternative products in their choice set.”

Here are the key results:

“In this study, we found that nutrient information conveyed through simple indices influences consumers’ grocery choices. Nutrient information increases willingness-to-pay (WTP) for healthy food and decreases WTP for unhealthy food. The added certainty provided by objective nutrient information increased the marginal WTP for healthy food. Moreover, there is a sort of loss aversion at play in that WTP for healthy vs. neutral food is lower than WTP for neutral vs. unhealthy food, and this loss aversion increases with information. . . . This study estimated the value of the nutrient index information at €0.98/family/day. The advantage of our approach is that the value of information reflects choices over a larger number of possible foods and represents an aggregate value over the whole day.”

I should also note that people valued the taste of their food as well.  We found consumers were willing to pay 4.33 eruos/kg more for a one-unit increase in on the -5 to +5 taste scale.  To put this number in perspective, let's take a closer look at the average taste rating given to all 173 food items. Most items had a mean rating above zero. The highest rated items on average were items like tomatoes (+4.1), green salad (+4), and zucchini (+3.9). The lowest rated items on average included cheese spread ( 0.2) and Orangina light ( 1.9). [remember: these were French consumers] Moving from one of the lower to higher rated items would induce a four-point change in the taste scale associated with a change in economic value of 4.33 ⁄ 4 = 17.32 euros/kg.”

Mandatory GMO Labeling Closer to Reality

I've written a lot about mandatory labeling of genetically engineered foods over the past couple years, and given current events, I thought I'd share a few thoughts about ongoing developments.  Given that the Senate has now passed a mandatory labeling law, and discussion has moved to the House, it appears the stars may be aligning such that a nationwide mandatory GMO labeling will become a reality.  

The national law would preempt state efforts to enact their own labeling laws, and it would require mandatory labeling of some genetically engineered foods (there are many exemptions and it is unclear whether the mandatory labels would be required on only foods that contain genetic material or also those - such as oil and sugar - which do not).  Food manufacturers and retailers can comply with the law in a variety of ways including on-package labeling and via QR codes.  Smaller manufacturers can comply by providing a web link or phone number for further information.  

Many groups that have, in the past, advocated for mandatory labeling are against the bill because, they say, it doesn't go far enough (e.g., this group is upset because it doesn't "drive Frankenfoods . . . off the market."). Other anti-mandatory labeling folks also don't like the bill because of philosophical opposition to signalling out a technology that poses no added safety risks.  

I suppose this is how democracy works.  Compromise.  Neither side got everything they wanted, but at least from my perspective, this is a law that provides some form of labeling, which will hopefully shelve this issue and allow us to move on to more important things in a way that is likely to have the least detrimental economic effects.   

I'm sympathetic to the arguments made by folks who continue to oppose mandatory labeling on the premise that our laws shouldn't be stigmatizing biotechnology.  Because a GMO isn't a single "thing" I agree the law is unhelpful insofar as giving consumers useful information about safety or environmental impact.  The law is also a bit hypocritical in terms of exempting some types of GMOs and not others.  One might also rightfully worry about when the government should have the power to compel speech and when it shouldn't.  And, I think we should be worried about laws which potentially hinder innovation in the food sector.  

But, here's the deal.  The Vermont law was soon going into effect anyway. The question wasn't whether a mandatory labeling law was going into effect but rather what kind.   The Vermont law was already starting have some impact in that state and would likely have had nationwide impacts.  Moreover, there didn't seem to be a practical legal or legislative way to prevent the law from going into effect in the foreseeable future.  

The worst economic consequences of mandatory labeling would have come about from those types of labels that were most likely to be perceived by consumers as a "skull and cross bones".   In my mind the current Senate bill avoided this worst case scenario while giving those consumers who really want to know about GMO content a means for making that determination.  That doesn't mean some anti-GMO groups won't use the labels as a way of singling out for protest companies that use foods and ingredients made with the technology, but at least the motives are more transparent in this case.  For some groups it was never about labeling anyway - it was about opposition to the technology.  That, in my opinion, is a much less tenable position, and is one that will hopefully be less successful in the long run.    

Support for GMO Labeling a Left-Wing Phenomenon?

Much has been written about whether aversion to biotechnology and GMOs has ideological dimensions rooted in the left.  I've written about this before, as have many others (this paper in Food Policy extends the discussion to a whole host of food regulations beyond biotechnology).  Most of the studies I've seen (including my own data) suggest only small differences in the left and the right in terms of beliefs about safety of eating GMOs.  However, as I previously argued:

“One distinction, which I think is missing, is the greater willingness of those on the left to regulate on economic issues, such as GMOs, than those on the right. Stated differently, there are questions of science: what are the risks of climate change or eating GMOs. And then there are more normative questions: given said risk, what should we do about it? Even if the left and the right agreed on the level of risk, I don’t think we should expect agreement on political action.”

Perhaps the clearest demonstration of this difference in willingness to regulate comes from a new paper by John Bovay and Julian Alston in the Journal of Agricultural and Resource Economics. They look at precinct-level voting data on the Prop 37 mandatory labeling initiative in California in 2012. One of the best predictors of support for Prop 37?  The share of people in the precinct voting for Obama. Here's a telling graph from their paper.   It's an almost perfect positive, linear relationship. 

The authors went on to use these results to predict what would have happened in other states if they'd had an opportunity to vote on Prop 37 (I should note we did something very similar in a paper on for votes on California's Prop 2 related to animal welfare in 2008).  Bovay and Alston found the following:

“Projections using our estimated model imply that a majority of voters in only three of fifty states (Hawaii, Rhode Island, and Vermont) plus the District of Columbia would have passed Proposition 37 had it been on their ballots in 2012”

Food Company Voluntarily Adds GMO Labels

This is a potential game changer (from the NYT):

“Breaking from its industry rivals, Campbell Soup will become the first major food company to begin disclosing the presence of genetically engineered ingredients like corn, soy and sugar beets in its products.”

A while back when writing about the duplicity of a many food companies on the issue of GMO labeling, I wrote

“For now, food companies are not required to add labels indicating the presence of genetically engineered ingredients. But, it might ultimately be in their best interest to do it voluntarily, and in a way that avoids the negative connotations implied by the labels that would have been mandated in state ballot initiatives.

Some day in the near future, after concerted efforts to educate the public and create consumer-oriented biotechnologies, we may see food companies clamoring to voluntarily add a label that proclaims: proudly made with biotechnology.”

Campbell's isn't going that far (and in fact they're supporting nationwide mandatory labels on foods with genetically engineered ingredients).  Nonetheless, this is an interesting move, and it will be fascinating to see how it plays out.

Impact of Process Labeling

The Council for Agricultural Science and Technology (CAST) just released a new paper on the impact of process food labeling.  The paper was written by a number of top-notch ag economists including Kent Messer, Marco Costanigro,  and Harry Kaiser.  It's a nice summary of the issues involved in the labeling of food processes (like organic or non-GMO or rbST free) as opposed to labeling food outcomes (like calories).

The summarize five points after reviewing the literature:

“1. Consumers want to have a sense of control over the foods their families eat.
2. Food markets are characterized by asymmetric information. Producers know more about the quality of the products than consumers. Many important quality traits are unknown until after consumption, or they are never revealed.
3. Consumers are not well informed about the various technologies used in the agricultural and food sector of the United States; however, they have greatly benefited from the tremendous technological progress that has occurred over the past century.
4. Consumers use process labels as cues to infer quality traits that are important to them, such as taste, food safety, and the environmental and societal impacts.
5. There is strong evidence that consumers consider process labels, frequently adjust their behavior in response to them, and, when these labels imply a negative aspect of a food, can shun that product. ”

They also present a number of challenges presented by these sorts of labels, such as

“Process labels can be used by marketers to stigmatize rival conventionally produced products, even when there is no scientific evidence that food produced in this manner
causes harm.”

The authors end with some policy recommendations.  Here's the first one:

“Mandatory labeling should only occur in situations in which the product has been scientifically demonstrated to harm human health.”