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You might be the food police if . . .

May 8, 2014

It has now been over a year since my book, the Food Police, came out. Despite the bad luck of it coming out on the day the Boston bombing happened (resulting in a slew of cancelled TV/radio appearances), it has been a fun ride.

I've had a lot of feedback. Some positive, some negative. As if to prove a point about the slowness of the academic publishing world, I've noticed two recent reviews of the book in academically-related publications: one in Agriculture and Human Values and one in Choices magazine. The tone of these reviews are a more negative than many of the others' I've seen, I suspect in part because this book wasn't geared for an academic audience per se and because the book takes issue with a lot of the presumptions that academics have about our ability to know what policies and choices will make people better off.

In any event, these reviews remind me of a common question I get from people that tend to be more critical of the book's message: who are the food police?

I thought the answer was rather obvious (the dedication page says: to those who wish to eat without a backseat driver).

But, in case it wasn't clear (and apparently it wasn't), perhaps I can have a little fun with the question. I'll pay tribute to Jeff Foxworthy's "you might be a redneck if . . ." jokes, by offering my own version.

You might be a member of the food police if . . .

you've ever advocated for a food policy without even considering the costs (much less conducting a serious cost-benefit analysis)

you think "natural" is good and "synthetic" is bad

you've said local foods are good for the environment or the economy

you've claimed organic crop yields are generally higher than non-organic

you thought Bloomberg's ban on large sodas was a "good first step"

you've claimed currently approved GMOs are unsafe to eat

you think added salt is natural but added sodium chloride is not

you think the world would be a better place if people just ate (and farmed) the way you wanted them to

your first response to the mention of a new food problem is a new regulation, tax, ban, or prohibition

you think food and agriculture were, on the whole, better in 1954 than 2014

you think sodas or fast food restaurants or gluten should be banned

you've offered taxpayers a free-lunch (the policy kind, not the food kind)

you believe "corporate greed' is the root cause of every food, health, and environmental problem

you've ever asked "who are the food police?"

O.k., O.k., not as funny as Foxworthy, but I think the point has been made . . .

If I were president, I would . . .

May 7, 2014

A while back, I visited my 3rd grade son's classroom. At my kids' school, the teachers often hang examples of the childrens' most recent projects or homeworks on the wall of the hallway.

Apparently, they had recently covered some lessons in civics or government because there were about twenty answers by 8-9 year-olds to the statement "If I were president, I would . . ."

I was struck my the large majority of responses that wanted to ban something or outlaw something, with a belief that there are no tough trade-offs, and anything the president wants, he could simply get. I enjoyed reading the responses, but it is a bit unsettling to see that many people's political views don't progress much from 3rd grade.

For your enjoyment, here are a few examples (I've corrected all the typos and grammatical issues, of which there were many, and made a few educated guesses about words in places)

End global warming. I would end bullying. I would give a speech to do it.
I would make everything FREE from diapers to bottles. I would make new tanks for the army.
I would make police nice.
I would make everything a dime.
I would make people get paid more for their jobs.
I would stop animal cruelty.
I would make everything free. So when you need something you could get it because it would be free. So if you needed a car to get somewhere it would be free so you could get it and go.
I would make it illegal to slaughter animals and make it make it to where you can bring animals in the store. They just have to be on a leash. And you could have a zebra.
Make it illegal for children to have soda.
Instruct architects to build houses for the poor, make school tests easier, and let people in college have more time with their family.
I would end all crime.
People can have pet tigers for free. Lots of people can own mansions. Taxes will not be high. There will be no war and everybody can be happy.
Ban war. I would make sure no war is happening in America. The army will be able to take a break. I would also ban drugs because they are dangerous.

And, the award for the child most likely to succeed in politics goes to this response:

I would have the teachers get paid more.

In case you're curious, here is my son's response:

It would only be $1 for everything. Ice cream would be $0 and so would candy. It would be great.

I wonder if he'll get to debate the little fellow who wants to ban soda? As you'll see from the picture below, his spelling skills are about like his dad's (thanks be to spell-checkers and copy-editors!).

Organic vs Conventional Crop Yields

May 5, 2014

The other day, I was asked whether I thought the price of organic foods would fall as the market share for organic increased. The answer is: it depends. If increases in consumer demand outpace supply, prices will rise. By contrast, if supply increases at a faster rate than consumers' willingness-to-pay for organic, prices will fall. I suspect that as Wal-Mart and other large retailers become bigger players in the organic market, it will bring about some cost efficiencies that are likely to lead to a reduction in organic price.

That said, organic will never be as inexpensive as non-organic (generally speaking, as I'm sure it might be possible for a particular crop in a particular location in a particular year to experience a price inversion).

Statements such as this normally invoke a debate about whether organic yields and costs are higher/lower than conventional yields and costs. For example, the following was written after a Twitter conversation on the subject

Again, the available data offers conflicting results: there’s evidence that organic yields can match conventional yields over the long-term, especially in less-than-ideal conditions. Other studies point to lower organic yields, especially in crops with high fertility requirements. The primary challenge in extrapolating these results to a “feeding the world” scenario is the issue of context.

Invariably, the evidence given in support of the argument that organic yields can surpass conventional yields is taken from organizations like the Leopold Institute (the paper referenced in the above quote was a proceedings paper, not one that went through the typical submission process) or the Rodale Institute that advocate on behalf of organic. That's why it is instructive to turn to larger scale literature reviews, like this one in the journal Agricultural Systems summarizing 362 studies, which shows that organic yields are 80% of conventional on average. Or turn to the top science journals, like Nature, where a recent paper showed that organic yields are typically 25% lower than non-organic. (note: these review studies show a lot of variability in the organic-conventional yield gap; sometimes the gap is large and sometimes is is almost non-existent).

The quality and quantity of the evidence quite clearly points to the fact that organic yields tend to be lower than non-organic. Yet, it seems, this never actually convinces anyone who believes the opposite. Thus, rather than a show-me-your-study-and-I'll-show-you-mine discussion, sometimes it is useful to make a conceptual argument.

The reason I would never expect organic yields to typically surpass non-organic is summarized in the following figure.

Here is the basic point conveyed in the picture above: a non-organic farmer is free to use any of the practices available to an organic farmer (e.g., no-till or low-till farming, cover crops, etc) but an organic farmer can only use some of the practices that are available to a non-organic farmer. Thus, the range of possible production practices, costs, and outcomes for organic must be a sub-set of that of non-organic.

Being an organic farmer implies following a set of rules defined by the USDA. These rules restrict the practices available to an organic farmer relative to a non-organic farmer. Organic farmers cannot use "synthetic" fertilizer, Roundup, biotechnology, atrazine, certain tillage practices, etc., etc. It is a basic fact of mathematical programming that adding constraints never leads to a higher optimum.

I suspect I know what an organic advocate will next argue: well in the long-run organic soils will build up nutrients and organic matter and will eventually achieve higher yields than non-organic. That may be (or may not be) true, but that does nothing to nullify my point. If it turns out that, say, 10 years down the road, organic farmers begin routinely experiencing higher yields, then non-organic farmers can copy those practices (assuming they're not higher cost) and again match organic yields, and eventually surpass them - because - yet again- they will have options available to them that organic farmers don't. Like biotech. Like ammonium nitrate.

Now, maybe organic better reduces environmental or human health externalities. I'm not particularly persuaded by the evidence on that front, but that is a reasonable debate worth having. But, arguing that organic yields can (generally) exceed non-organic yields is not supported by the best empirical evidence or by logic.

Does eating chicken on the bone make children more violent?

May 2, 2014

That is the finding of a study published in the journal Eating Behaviors. I have a lot of admiration for the study's lead author, Brian Winsink (I highly recommend his book Mindless Eating), but I'm going to have to file this one under "I don't believe it."

I thought it was worth weighing in on since I'd seen the study reported on in several major media outlets. I'm not saying that it isn't possible that eating chicken on the bone (vs. in chunks) doesn't cause aggression, I'm just saying that my priors are such that it will take a lot more than this to convince me.

Why would we even expect that eating chicken on the bone causes aggression? The authors suggest the following hypothesis:

Showing teeth is a common sign of aggression in the animal world. Dogs retract their lips and bare their teeth as a sign that they are willing to fight (Galac, & Knol, 1997). The baring of teeth may have similar meaning in intuitive human behavior

So, the authors ran an experiment.

They took 12 children participating in a 4-H summer camp (yes, N=12), and split them in two groups, 6 in one and 6 in another. On day 1, one group was fed chunks and the other group was fed chicken on the bone. On day 2 , they reversed the foods fed to the groups. On both days, the children's behavior was monitored and recorded. For example, the children were asked to stay in a circle and the monitors counted the number of times the children left the circle (glad I didn't go to that 4-H camp!). Paired t-tests were used to test whether behavior differed on the day the child got the bone vs. the chunk.

Here are some shortcomings of the study that make the results a bit hard to believe:

The small sample size.
Each child was only observed on 2 days (one with bone one with chunk). However, on one day, the temperature was 97 degrees and on the other it was 76. Lots of prior research has posited a link between temperature and aggression (hot = more aggressive). Suppose you had a couple kids in a group with a tendency toward aggression who got assigned chunks on the colder (76 degree) day and bones on the hotter (97 degree) day? The difference in their behavior may be due to temperature not bones. It would be nice to see tests for within-day differences in bone vs. chunk. If one had a large sample with random assignment to treatments on multiple days this wouldn't be as much of a concern, but it certainly is here.
Children assigned to the same group sat at the same table together. This may have produced some sort of group dynamic. Suppose, for example, the kids assigned to bone started arguing at the table and the conflict spilled over to the playground. The current study cannot separate group-day effects from the treatment effect (bone vs. chunk).
Given the small sample size, really all it takes is one or two kids changing behavior from day 1 to day 2. How do we know this wasn't due to something at home that carried over to the camp? With such a small number of observations, I don't know why the authors didn't just report the entire data set in one table. That way, we could see whether the difference was from a small increase in aggression of every child or a large increase in aggression of 1 o 2 kids.
The counselors who kept the kids in the circle and who rated behavior were "blind" as to the treatment and control groups each day. That's good. However, the study doesn't tell us whether the people who subsequently watched the videos and rated behavior were also blinded.
Maybe the effect exists but for very different reasons than those hypothesized in the paper. I've already mentioned a temperature explanation. What if children like to eat chicken on the bones more than they do in chunks (my kids certainly do). Maybe they get more excited and rambunctious when they get a "treat" or something they like, which the current authors attribute to "aggression." Perhaps when the counselors give the kids a food that the kids perceive as more generous or benevolent, it signals to the kids that the counselors will subsequently be more permissive. To control for this, you'd want some treatments where the bone-in food was less desirable than the boneless food.

At the end of their article, the authors suggest a number of lines of additional research that are interesting and worthwhile. But, they also give some advice. The authors suggest

school cafeterias may reconsider the types of food they serve if it is known that there are behavioral advantages to serving food in bite-size pieces

and

it may not be wise to serve young children chicken wings shortly before bedtime, or to serve steak and corn-on-the-cobb in the company of dinner guests.

That may be good advice in general, but this study alone is insufficient reason to re-engineer lunch lines or dinner plans in an effort to reduce child aggression.