Questionable assumptions: the obesity problem

You can hardly read a day’s worth of news without hearing about someone whipping up the moral panic over obesity. Oftentimes, it’s busybody politicians trying to solve this putative problem with some heavy-handed government intervention (like this one). Proponents of such interventions almost always claim that they have the moral jurisdiction to impose them because obesity incurs health care costs that the public must bear. Now, the libertarian in me wants to object to the two-wrongs-make-a-right reasoning of forcing people to participate in broadly socialized medicine and then leveraging that to dictate any aspect of their lives that might have the faintest effect on their health. I’ll put that aside for now, though.

What I want to ask now is, is the evidence that obese people cost more in the long run really that strong? Yes, obese people incur higher health costs per year of their lives, but their lives are shorter, and our end-of-life health care spending is disproportionately large. Some of the nannies point to statistics that obese people take more sick days and, thus, are less productive to boot. But this is a bad argument for two reasons. First, most people find the difference between incurring a public cost and failing to add as much to the public coffers as morally relevant. Even if we grant that the former justifies government intervention, it hardly follows that the latter does. Second, once you start thinking along these lines, you start to see how hard it is to properly measure the net, all-in cost of obesity. Maybe obese people take more sick days, but what about total work hours? Do they spend more time at the office because they’re not taking extra-long racquetball lunches? Do they, on average, have fewer social engagements for which to shirk work duties? Does their early death lead to early retirement, causing them to exit the workforce before they become the highly-paid-yet-less-productive old guy at the office? I think it’s clearly impossible to hold a justifiable belief on this point without digging deeply into the data. And “digging deeply” does not mean citing a handful of studies without looking into their methodology. Given the difficulty of measuring something like this and the ease with which researcher bias can creep into such investigations, we need to see some highly robust results over a large number of investigations. And keep in mind that while “overweight” and “obese” refer to discrete BMI categories, the reality is more complicated. Being a little overweight can have much different implications for different variables than being really overweight, obese, or moderately overweight. Are these government interventions going to have the desired effect on people at every point on the spectrum? Highly unlikely.

I’m certainly not the first person to raise this objection. (A quick consult with Google turns up several articles like this one.) However, I think it bears repeating because its clear that the public dialog, at least, has not addressed it sufficiently. In fact, at this point, this should be the only issue in the public dialog. We shouldn’t even be talking about interventions at this point because there seems to be about as good a chance that these interventions, if they have any effect at all, will exacerbate our health care entitlement problem as improve it.

Some brave nannies might bite the bullet and say government meddling is justified regardless of its effects on health care spending. People aren’t doing what’s best for them, and government is here to fix it, dammit! However, this is just arrogance. Even though I obviously personally place a lot of value on staying slim and healthy, I’m not at all confident that other people share my preferences to a degree sufficient to warrant violating their autonomy here. Who am I to say that a person shouldn’t be allowed to trade a few years of his life for the ability to enjoy cheesecake worry-free every other day? Maybe he will be happier in the end. And while exercise almost certainly extends the lifespan of the average practitioner, high-level professional athletics very likely reduces one’s lifespan and quality of life in a number of respects. Are we going to ban sodas and footballs?

My guess is that most obesity nannies are driven primarily by the urge to control other people’s lives. They haphazardly dispense public finance-based justifications because they’re necessary to build public support. Hence, they’re not at all interested in subjecting those justifications to any kind of critical eye.


5 Responses to “Questionable assumptions: the obesity problem”

  • If fat really do die sooner then they will collect less social security benefits. Also I imagine that everybody incurs significant health care expenses in their final years regardless if it is a fat person dying at 65 or a thin person dying at 85. Difference is the thin person was on medicare for two decades longer.

  • Great read, Piyo. I think you’re writing skills are improving with each entry.

  • What interventions are you referring to? Bloombergs soda ban?

    Piyo, while being obese / severely obese reduces your life span up to 10 years (1), it isnt fair to go on to say that since the obese die sooner, their health care costs fail to be higher. To the contrary, they are considerably higher due to the fact they incur medical care at a much earlier age in their life.

    For example, an extremely obese teenager might die when he turns 55, but he will begin incurring medical care at 15.

    Furthermore, the costs of obesity are fairly clear, around 190 billion a year (2).

    What isnt clear, however, is whether or nor Bloombergs soda ban is a good idea. I would say no, considering prohibitions long history of never, ever working for any substance, ever.

    1 – Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies
    Prospective Studies Collaboration
    The Lancet – 28 March 2009 ( Vol. 373, Issue 9669, Pages 1083-1096 )
    DOI: 10.1016/S0140-6736(09)60318-

    2 – John Cawley, Chad Meyerhoefer
    The medical care costs of obesity: An instrumental variables approach ☆
    Journal of Health Economics, Volume 31, Issue 1, January 2012, Pages 219–230

    • By “intervention”, I mean any government initiative whatsoever to reduce obesity.

      Piyo, while being obese / severely obese reduces your life span up to 10 years (1), it isnt fair to go on to say that since the obese die sooner, their health care costs fail to be higher.

      I don’t think it’s “fair” to say anything at the moment. That is my point. It seems clear that obese people go to the doctor more while they’re here. It also seems clear they aren’t “here” as long. Nothing else is obvious. While, in the end, I think one should be hard pressed to disagree with the scientific consensus, there is nothing resembling a scientific consensus on this particular question right now.

      Your first citation doesn’t seem to address lifetime, net costs at all, only mortality. So, I’m not really sure it’s relevant.

      I can’t find an ungated version of your second citation. However,

      1) It’s not clear that it attempts to account for the early death of the obese. If it doesn’t do that, I don’t think it’s relevant.
      2) They state at the beginning that this is the first study to use to the “instrumental variables” approach to study this question. I don’t know what that is, but it certainly means that we should take its conclusions with a grain of salt until other studies use this approach.
      3) Even if it hadn’t used a novel approach, it’s still just one study, and the conclusions of most scientific studies are false. How many studies could you find 15 or 20 years ago that suggested Americans should switch from saturated fats to trans-fat?
      4) Even if I grant you everything else, a proper cost benefit analysis can’t stop at the question of whether or not obese people cost more. It has to at least show that the expected savings is enough to cover the cost of the interventions themselves. It doesn’t matter if you save a billion each year because people are skinny if it costs you two billion to make them skinny.

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