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:
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.
Here are the key results:
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.