Obesity: Class Warfare, Imperfect Information... or both?

Saw this on CNN today: Poor and fat: The real class war, by L.Z. Granderson. Some figures from the article:

Ground beef that is 80/20 is fattier but cheaper than 90/10. Ground turkey breast is leaner than the other two but is usually the more expensive. And many of us can't even begin to think about free-range chicken and organic produce -- food without pesticides and antibiotics that'll cost you a second mortgage in no time at all.
...The American Journal of Clinical Nutrition recently published a study that found $1 could buy 1,200 calories of potato chips but just 250 calories of vegetables and 170 calories of fresh fruit. And it is also true that Mississippi, the poorest state in the country, is also the fattest.
In fact, the five poorest states are also among the 10 fattest, and eight of the 10 poorest states are also among the 10 with the lowest life expectancy.
I guess one could dismiss this as one big coincidence, but is it also a coincidence that half of the top 10 states with the highest median incomes are also in the top 10 in life expectancy?

I would interpret Granderson's argument as: low-income leads to unhealthy foods leads to fat (leads to more healthcare spending and even lower incomes). Looking at calorie counts compared to food prices does seem to support that. However, bringing some micro theory into the discussion complicates this causal story somewhat.

We can quantify the effect of income on food choices through this simplified model. Imagine two different families, both trying to fill a calorie requirement of 2000, but the low-income family has a food budget of $3 and the high-income family has a food budget of $10.

After plugging numbers into the formula above, the high-income family buys only 0.3 servings of potato chips and 9.7 servings of fruit, while the low-income family gets about 1.4 servings of potato chips and 1.6 servings of fruit.

The same intuition is expressed graphically below. Purchasing decisions are represented by points where the red and blue lines cross.

So far, so good: as one would expect, the high-income family buys more fruit and less potato chips than the low income family. One problem for this example, though, is that neither of these families will be gaining any weight!

If people only eat the necessary calories to keep an even weight, it won't matter whether their income is high or low. They'll just adjust their purchasing choices to get the right amount of calories. A dietitian might frown on you for eating chips as a snack instead of fruit, but as long as your consumption of chips is small, it won't necessarily cause you to gain weight.

It takes some extra assumptions to model over-eating. Maybe there's some property of potato chips that causes people to eat too much of them, i.e. what if someone buys potato chips thinking that a $1 serving will be 1200 calories, when it's actually equivalent to 1600 calories? Keeping with the numerical example above, the rich family would overeat by about 120 calories and the poor family by 560 calories.

It's only imperfect information or self-control problems which make food choices cause weight-gain. If we assume that low- and high-income types have exactly the same sort of bounded information, we'll find that the rich gain less weight, because their greater resources have them purchasing less unhealthy food to begin with.

This story gets even more pessimistic if there is some difference between low- and high-income people's capacity to overcome imperfect information. It might be that the poor have less time/energy to research and craft their diet than the rich do, so they are more prone to mistakes. Additionally, there could be some personal attribute - an impulsive nature or low conscientiousness - which both causes someone to have low income and also makes diet control more difficult.

While the costs of obesity are worth addressing given their heavy contribution to public healthcare spending, as Granderson rightly observes, the lens of class warfare isn't the best for understanding the problem.

Ultimately, to prevent obesity people need more incentive to monitor their own health. For me, it's knowing that on the current trajectory of public health care spending, there probably won't be any money left by the time I'm old and infirm. It doesn't entirely surprise that current beneficiaries of public health care are not too concerned about solving this spending problem for the rest of us (morbid fact: about a third of health care spending goes to patients in their last year of life). Which class is under attack, and which class is attacking anyway?

Maybe the obesity problem will resolve itself as young people make the calculations and figure they will likely be on their own, in terms of medical care, by the time it is most necessary. Or maybe the lure of potato chips is simply too great for us as a nation and will lead to our fiscal undoing.

Farm Subsidies: A Picture Worth 1,000 Words

Who ever said there's no skiing in Iowa? Source.

In other news, the Institute of Medicine is advising the government to adopt a series of policies to control the American "obesity epidemic." One such policy is a proposed "soda tax."

I have a better idea. Instead of taxing soda, why don't we repeal the subsidies which makes the primary ingredient, high-fructose corn syrup, so dirt cheap to produce?

Komen Foundation Pilloried for Planned Parenthood Policy - and Rightly So

Earlier this week the Susan G. Komen for the Cure Foundation said they'd be eliminating their grants to Planned Parenthood for breast cancer screenings. The resulting social media uproar, however, quickly caused them to reverse that decision and issue a sickly-sweet apology press release.

I know blood in the water when I see it; my duty to the blogosphere wouldn't be met without helping to smear Komen's momentarily-vulnerable public image further. After all, it's not every day you can feel righteous while slinging mud on a charity.

The recent furor raises a broader question: how much of what the Komen Foundation does is actually getting us closer to a cure for breast cancer? According to their website, 84% is spent "on our mission." But, that "mission" is defined pretty broadly.

From Komen's donation page.

The screenings, research, and treatment services that Komen provides are definitely valuable, but those only make up 46% of the overall budget. That leaves 54% percent taken up by administration, fundraising and "education" (a.k.a. advertisements). Basically, for every dollar that Komen takes in, a little over half of it goes out toward seeking another dollar. It's inefficient.

Maybe "education" about the risk of breast cancer is important, and causes some people to get treatment who otherwise would not. But, there are obviously some diminishing returns to awareness. Breast and prostate cancer are the number two causes of cancer-related deaths for women and men, respectively, but breast cancer receives much more public money and attention.

Data source: Aminou R, Altekruse SF, Edwards BK, et al. SEER Cancer Statistics Review: 1975-2006. Cancer Statistics, National Cancer Institute. May 29, 2009

A cynic would say that it's more fun to talk about breasts than the inside of men's asses, and probably be right. Some recent "sexy" breast cancer awareness campaigns help to reinforce that cynical view. While the incidence of prostate cancer has risen rapidly over the last 20 years, much faster than the rate of breast cancer, the National Cancer Institute spent twice as much on breast cancer as it did on prostate cancer in 2008.

There shouldn't have to be a fight between different anti-cancer organizations for funding. All of these diseases deserve serious study and research toward a cure. But, there also shouldn't be pseudo-political organizations like the Komen Foundation sucking up resources for runs, pink ribbons, Facebook campaigns, "awareness", and other things commonly known to not stop cancer. If you want your donation to make a difference, write a check to a research lab, not a lobbying group. With their stance on Planned Parenthood, the Komen Foundation has revealed itself to be much closer to the latter.

I Have No New Years Resolutions.

The New Year is a nice time, symbolically, to make a big change in life but practically it almost never works out that way. From a Boston Globe article, I learned that 80% of New Years resolutions are broken. Frankly, I'm surprised that as many as 20% are accomplished! People don't change much on the eve of December 31 to the morning of January 1 (perhaps except for the addition of a hangover) so I suspect much of the 20% accomplished are trivial ("remember to call my mom on her birthday this year") and require single actions, not sustained effort.

Resolutions are puzzling from both an economic and psychological perspective. To an economist, there's no reason why one day should be intrinsically more favorable than another to make a positive life change. If drinking less or exercising more would be a good idea, why wait until January 1st to start doing it? On the other hand, a psychologist might wonder why people set themselves up for failure so often. If 80% of resolutions ultimately amount to lying to yourself, why persist in encouraging such a mentally unhealthy activity?

The real question: if most resolutions would be good things to accomplish, why are people so bad at keeping them? It's easy to just dismiss New Years resolutions as "cheap talk" which people utter in order to sound socially acceptable and make themselves feel better, with no intent of actually following through. But, I think there's a little bit more to it than that.

In their book, Willpower: Rediscovering the Greatest Human Strength, Roy Baumeister and John Tierney offer a pretty good explanation for why New Years resolutions have such a short shelf-life. When someone creates a list of challenging self-improvement tasks, they are probably very optimistic about their future state of mind. But, realistically, we only have so much willpower to divide between different goals that require self-control. Willpower, in this regard, is somewhat like a muscle: when it is used lots in a short span of time it becomes fatigued, so later acts of self-control are more difficult. Creating a list of resolutions is like weight-lifting beyond the mind's capacity; it can't dedicate enough mental power to accomplish all the goals at once, so in the end none of them are met. As a result, creating a big list of dramatic changes is one of the least effective ways to actually modify your own behavior.

A better strategy is to choose one area that seems most important and focus on moderate improvements. Also like a muscle, willpower can become stronger when exercised. Picking reasonable goals gives a sense of accomplishment when they are completed, making it easier to stick with other changes in the future. In other words, build up capacity slowly to avoid a painful sprain of the willpower muscle (although if I stretch this analogy much further, I might suffer a tear in my credibility). Introducing the concept of willpower to economic thinking means we don't have to dismiss failed self-improvement projects as mere cheap talk, and can instead look more realistically at the human mind and its practical limitations.

"Fat Head": why fat is good and nutritionists are wrong.

My role model.

I try to blog on topics within my field - economics - which is usually easy, because economics encompasses almost everything. However, I recently watched a health documentary which inspired me to brave the big, scary world of health and nutrition. Written and directed by former health writer and comedian Tom Naughton, "Fat Head" is a must-watch for everyone, especially those who liked and/or took seriously Morgan Spurlock's "Supersize Me."

Available on Netflix and Hulu as well for sale off the creators website, "Fat Head" is a quick, fun and informative video. However, for those who want the factual gist of it without the cheesy (but amusing) commentary and animations, I present this partially-digested version of the food documentary, broken into three main chunks for easy consumption.


1. The numbers in "Supersize Me" don't add up. In the movie, Spurlock's nutritionist repeatedly says he's consuming over 5,000 calories per day. Problem is, according to Spurlock's own rules, he only had three square meals per day. Even if he Super-Sized at every opportunity (which he claims not to have done) that still only adds up to a rough 3,600 calories. Where'd the rest come from? He must have added several desserts. If someone stuffs themselves with over twice the calories required for a healthy adult... is it really surprising that they gained weight?

Inefficiency of health, education sectors is more than coincidence or the "Baumol effect."

From The Economist, March 17:

Larry Summers, Mr. Obama's main economic adviser till the end of 2010, argues that the goods governments buy, especially health care and education, have proved much more resistant to productivity enhancements than the rest of the economy. Since the 1970s real wages in America have risen tenfold if you measure them against the cost of televisions; set against the cost of health care, they have gone down.
Mr. Summers expects that trend to continue. An ageing population will need ever more health services provided by the state...

Unintentionally, Mr. Summers has presented some truly fabulous arguments against the increase in government spending he seems to advocate.

Is it truly just random chance or amazing foresight which has led the state to invest in sectors which just happen to be resistant to productivity enhancements? The Economist article points to the so-called Baumol effect, whereby some activities are immune to improvements in labor productivity. For example, it still takes the same number of musicians to perform a Beethoven symphony as it did in the 1800s.

To me, this seems like a completely inadequate explanation for the growing costs of education and health care. Unlike symphonies, there have been many technological improvements which should make the provision of those services much cheaper. Increased access to computers has revolutionized other industries and this would seem to be especially true in health or education, where the rapid and accurate transfer of information matters especially. But that hasn't happened.

There is a much simpler explanation: more government intervention causes higher costs. As health and education became increasingly regulated, the incentive to increase productivity became smaller. Teachers and doctors have to satisfy the demands of politicians and not just the parents or patients. There's no reason to rein in costs because taxpayers will foot the bill regardless.

I'd speculate that if the government had decided to regulate and oversee the production of symphony music, it would take twice as many people as it did to perform in the 19th century (and they'd miss twice as many notes). Instead, we have a medical industry that kills 98,000 people per year with preventable accidents, and an educational system that spends the most in the world but can't keep us in the top ten for global rankings of student proficiency in basic math and sciences.

Is this really a success story for government social spending? To me, it sounds like a reason to chop down the vines of red tape choking the market for education and health care. If costs continue to rise after the government's influence has ended, there may actually be an argument for the Baumol effect. Until then it's just empty apologetics.

Statistical Fallacy #002: Confusing Correlation with Causation. Does a strong handshake really make you live longer?

Even highly educated and intelligent medical researchers aren't immune to statistical errors. A recent study in the British Medical Journal referenced 33 other studies on personal mobility and life expectancy, and compiled their results. According to Reuters, 

They found simple measures of physical capability like shaking hands, walking, getting up from a chair and balancing on one leg were related to life span, even after accounting for age, sex and body size. 

While the phrase "accounting for age, sex and body size" makes this process sound very objective and scientific, there are obviously a lot of other factors that can play a role in life expectancy. Personal differences, such as leading a more active lifestyle, could cause someone to have both more hand strength and also better health in general which contributes to their longevity.


While statistics saying "the death rate over the period of the studies for people with weak handshakes was 67 percent higher than for people with a firm grip" sound very dramatic, it's hard to say if that relationship is reverse-causal; in other words, having a weak grip may signal your lifespan will be short, but will improving your grip really make you live longer? Probably not, which suggests it's far more likely that a common variable - for example, sitting on the coach all day - causes both weak hands and a lower life expectancy.


Common sense says that working with a stress ball or doing forearm exercises to develop a crushing handshake probably won't substantially reduce your chance of death from heart disease, cancer, stroke, or the other leading causes of death for adult Americans. However, this is exactly the impression given by the Reuters article title "Want to live longer? Get a grip!" Heavens forbid someone took this seriously and developed gorilla-like forearms only to find out their fitness investment had been in vain.

Busting the 'egg scandal' wide open.

These eggs were not broken to make an omelet.

Recently, Wright County Egg and Hillandale Farms, both located in lovable Iowa, have come under fire for "poisoning" the public with salmonella from their eggs. An egg source for 13 different retail brands, this news has rocked supermarkets nationally, and an even wider recall might be in the works.

"The history of ignoring the law makes the sickening of 1,300 and the forced recall of 550 million eggs shockingly understandable," says William D. Marler, a Seattle attorney representing someone who became ill from a 'dangerous' egg salad. (They're all dangerous in my opinion, especially on a hot day).

The numbers above got me wondering. What proportion of the recalled eggs were contaminated with salmonella? If 550,000,000 eggs resulted in 1,300 people becoming sick, the chance of any one egg making someone ill is .000236% . Eat a whole dozen, and your odds skyrocket to .0028%, a roughly one-in-35,000 chance of becoming ill from a tainted egg.

Surely, if you're one of those 1,300 people, hearing the numbers won't cure your stomach-ache and flu symptoms, but it should be reassuring for the other 99.99% of the population. Salmonella can be dangerous for the very young and very old, but many cases are so mild they aren't even reported.