The ecological fallacy

Martin Cothran has, he likes to remind people, written a book on logic, and teaches the subject at the high school level. Alas and alack, this stooge of the Disco. Inst. and Focus on (your own damn) Family cannot seem to apply it correctly in his writings. Today, he illustrates rather starkly the ecological fallacy while making the not-at-all revolutionary observation that wealthier Americans are skinnier than poorer ones:

Now comes more evidence that poverty in American is characterized chiefly by eating too much. The report, from the Robert Woods Johnson Foundation, has Mississippi, Alabama, West Virginia, Tennessee, and South Carolina as the five states with the highest rates of obesity. It does not make any claims about the relation between poverty and obesity, but what do you want to bet that if you took the mean income and compared it to the level of obesity, you would have a strong correlation?

The fact that these states are the poorest and also the most obese does not mean that the poorest people in these states are the most obese, naturally. This is the ecological fallacy at work, the fallacy of assuming that individuals in a statistical population all share the average properties of the group. For instance, reading the data above to show that Mississippians are all both fat and poor.

Then Cothran confuses correlation with causation, which would be invalid even if he had data showing that correlation.

And of course, there is a relationship to be found. Wealthier Americans tend to be thinner than lower middle class and lower class Americans. I haven’t seen data on people below the poverty line, so I don’t know how far down the income scale that trend persists. But obesity is a bad measure for adequate nutrition. Food isn’t just about caloric intake, it’s also about vitamins and minerals, essential amino acids and lipids. People get fat because calories are cheap. Corn syrup is subsidized so that it’s sold below the cost to produce it. It’s cheap and easy to bulk things up on calories.

You can get a few thousand calories for a couple dollars at McDonalds, but those are calories from fat and processed corn. The food is laced with preservatives and pesticides, and it’s missing vitamins and minerals. Someone who lives on fast food for a month will wind up malnourished in a meaningful sense, but won’t have lost weight. He’ll be unwell and obese, poorly fed but not hungry.

Good food costs money. Most organically grown items at the farmers markets I shop at cost 2-3 times what a conventionally grown item might cost at a supermarket. But I’ll pay it, because it encourages local agriculture, because I don’t have to worry about pesticides, and I don’t have to fear the preservatives and additives that are added to everything up to and including raw meat at the supermarket. It’s healthier for me, for my community, and for the environment. But it costs money. Turns out I can fill up on greens just as well as on Fritos, and it doesn’t cost that much more, and it doesn’t make me obese.

There was a striking moment in Food, Inc. that illustrated the problem. A family is talking about the challenge of feeding 5 mouths on two poorly-paid salaries (I think they worked at a meat processing plant). Their budget requires that they spend no more than a dollar on lunch for each family member. At the supermarket, the single pear the youngest daughter selects would blow her whole lunch budget, while the same dollar would buy her a hamburger and a soda at a fast food joint. Understandably, she chooses to buy the more filling, but less healthy, fast food.

i-8d80a54c7082e9d9846323ec7fb855e9-200907012122.jpgThe US Department of Agriculture measures food insecurity not only in terms of hunger, but based on “reduced quality, variety, or desirability of diet,” with “very low food security” being evidenced by reduced food intake (in any form) and disruption of eating patterns, as in skipping meals for financial reasons. By this standard, a family subsisting on hamburgers and soda has low food insecurity, but not very low food insecurity. Food insecurity affects 11.1% of households, with 4.1% in the “very low food security” category in 2007.
By the measure of the figure here, few food secure people are worried about missing meals, about having unbalanced meals, or are going hungry. Even food insecure people generally find ways to maintain body weight, but at the cost of unbalanced meals and stress about running out of food.

Cothran dismisses “people who are claiming there is a ‘hunger’ problem in America” when 4% of the population in the richest and most powerful nation on the planet cannot get enough to eat. Someone’s heart needs to grow a few sizes.

The USDA adds that, as of 2007: “Overall, households with children had nearly twice the rate of food insecurity (15.8 percent) as those without children (8.7 percent).” That trend is worrisome because malnourishment (in terms of nutrients and calories) affects a child’s growth and mental development. These kids may be fat (which puts them at risk for diabetes), but they aren’t getting vitamins and essential fatty acids needed for a growing brain. And the calories they are getting come alongside pesticides and preservatives which mimic the effects of naturally produced hormones. Hormones which control how and when different body parts grow. Hormones that determine whether male or female genitalia grow. Hormones that induce puberty. This is not small potatoes we’re playing with.

Rates of food insecurity are up in recent years. Very low food security was found in only 2.85% of families during the Clinton years, rising to its current peak during the Bush administration. Eleven percent of families may not seem like much, but even one family going without food is too many. Cothran can mock all he wants, but it would be nice if he didn’t demonstrate his logical incompetence while he’s at it.


  1. #1 jay
    July 2, 2009

    You seem to be speaking from stereotypes here too. People can spend MUCH less than eating fast food and still get a reasonable diet, without jumping onto the new-agey ‘organic’ wagon.

    obviously people with near zero money have a problem but in general food is a lower part of income here than in much of the world and all but a few percent of the population (who may legitimately need help) CAN afford to eat a reasonable, though not luxurious diet.

    Of course if we were all forced to go back to labor intensive (i.e. expensive) ‘organic’ methods, there would be a lot more hunger.

  2. #2 Pierce R. Butler
    July 2, 2009

    Cochran & Co. present an interesting challenge to the “accommodationist” school of thought.

    If, as the Strident New Atheists™ might predict, such materialistic fact-based responses as the above fail to enlighten even a minor Dobson minion, what is the next step in confronting his (ahem) delusions?

  3. #3 Jim Thomerson
    July 2, 2009

    Most poor people do not have easy access to quality food. Supermarkets, much less farmer’s markets, are not usually located in poverty areas. So it may well be that the best a poor person can manage is slim jims, twinkes, and diet pepsi at the local convenience store. And, of course, food costs more at a small convenience store than at a supermarket. I think I have read of efforts being made to get some supermarkets established in poor areas.

  4. #4 mark
    July 3, 2009

    Public radio recently had an item about preparing tasty, nutritious meals on small budgets. Interviewees described their meal plans–good, doable, but not very easy if you lack the knowledge and access to ingredients.
    Don’t forget to mention that those in poverty also have moral failures; otherwise, they would be wealthy.

  5. #5 Jim Thomerson
    July 5, 2009

    To quote my grandfather, “So long as you have cornbread and sorghum molasses you can get by.”

  6. #6 Gail
    July 12, 2009

    While it is true that fresh high quality produce is very expensive, a poor person does not have to resort to slim jims, twinkies and diet pepsi. Beans, brown rice, legumes such as lentils, and other whole grains can form the basis of an extremely healthy diet, and so far are quite cheap. They can be augmented with small amounts of vegetables and meat for flavor and variety. I think part of the problem is that Americans expect to eat large quantities of meat, and have forgotten how to cook. Another very significant problem contributing to obesity is the pollution that mimics hormones – as well as actual hormones from medicines – finding their way into food and water supplies that affect metabolism, as mentioned in the post.

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