Sunday, September 25, 2011

Mark Bittman's war on junk food

Mart Bittman had another complaint about junk food following last month's long article on why we should tax it. Today, he explained that junk food was actually more expensive than "better food" and so that the difference in prices is not the reason why junk food is so popular.

I have a couple of problems with his argument. First, he argues that the main problem is that people do not want to cook. But this can be explained as a price problem: once you account for the cost of cooking(and not only the concrete costs of utensils and all, but also time), is it clear that fast food is more expensive than, say, organic food?

Second, Bittman links junk food and tobacco in an interesting way. First, he explains that junk food is addictive:
A 2009 study by the Scripps Research Institute indicates that overconsumption of fast food “triggers addiction-like neuroaddictive responses” in the brain, making it harder to trigger the release of dopamine. 
This leads him to argue that "real cultural changes are needed to turn [the problem] around". For him, the question is "How do you change a culture?" and he explains that this is what the tobacco market has done since the late nineties "Smoking had to be converted from a cool habit into one practiced by pariahs". The weirdest part, for me, is when he argues that we should "give [our children] the pleasures of nourishing one another and enjoying that nourishment together".

First, I have a problem with the "cultural" argument, because it seems to be quite vague, and also intractable. Indeed, how do you change a culture? More problematically, what is culture? Who decides what "culture" is the target culture?

Second, although the addictive component of junk food is a nice way of to see that junk food is similar to, say, tobacco, I don't understand the follow-up. It is not clear to me that the objective, and the effect, of the anti-cigarette campaigns were to transform people into pariahs. It seems to me that there was a campaign of information and an increase in costs so that people would be better informed of the consequences(e.g. pictures on cigarette packs), and so that the externality cost would be internalized by consumers(increase taxes on packs). I am not sure there was a culture war against cigarette.

This being said, even if one accepts the cultural argument, I think Bittman has his policy prescription wrong. It is not clear to me that you need a big cultural shift. Malcolm Gladwell has a nice discussion of the cigarette problem in The Tipping Point. First, smoking and depression are closely related, and anti-depressants have a significant impact on the rate of smoking quits. Second, addiction is not instantaneous and it affects people differently(e.g. here).  You can wait years before being addicted, and some people can smoke regularly and never get addicted. This means that the share of nicotine content in cigarettes can be lowered slightly and have huge impacts. More importantly for the argument here, Gladwell says that
We've been obsessed with changing attitudes toward tobacco on a mass scale, but we haven't managed to reach the groups whose attitude needs to change the most. 
For cigarettes, informing and increasing prices are ways to make the "market" better. Targeting nicotine levels and using anti-depressants are ways to solve the addiction problem. The former thing was what makes me more sympathetic to Bittman's first argument in favor of taxing food, and also argues in favor of the new health care law requirement that calories be posted(there is evidence, however, that that does not work. But it is not clear!). On the second point, well,  apparently nicotine and junk food both act on the level of released dopamine, so hopefully we can find ways to target addiction.

I want to conclude on another link, slightly related. As I mentioned above, calorie posting on menus does not seem to work especially for low-income people, which is, I believe, the population that Bittman wants to target. Interestingly, in their new book, Abhijit Banerjee and Esther Duflo explain that when people are budget constrained and cannot afford the desirable number of calories, giving them extra money will not lead them to spend all of this money on food, and the food they'll purchase will be less "efficient" in terms of calories("television is more important than food!"). They refer to a recent paper by Jensen and Miller who ran a randomized-controlled trial showing that "households that received subsidies for rice or wheat consumed less of those two items and ate more shrimp and meat(...) Remarkably, overall, the caloric intake of those who received the subsidy did not increase". Duflo and Banerjee seem to argue in favor of paternalistic policies, such as giving way fortified foods to parents and more generally, providing more directly better-quality food to poor families. It is not clear, however, that this is what they would advocate in a country with better institutions. Interestingly, they mention the information problem:
They[The poor] often behave as if they think that any change that is significant enough to be worth sacrificing for will simply take too long. This could explain why they focus on the here and now(...)
This is clearly not specific to any category of people. The instantaneous pleasure of junk food or of cigarette, and the general short-termism, affects everybody except George Clooney. This means that we do not compute the real costs of short-term behavior(and Banerjee and Duflo show evidence that the poor, for instance, would like to constrain their future behavior on health the same way anybody would like to have a commitment device for new year's resolutions). So improving information and, more controversially, increasing costs(also because of the externalities we're talking about), is still fine with me.

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