No, Farm Policy Doesn't Have Much to Do with Obesity

Yesterday, David Ludwig and Kenneth Rogoff, prominent pediatrician and economist respectively, published an article in the New York Times about obesity.  The following is a passage from the piece.  

Farm policies have made low-nutritional commodities exceptionally cheap, providing the food industry with enormous incentive to market processed foods comprised mainly of refined grains and added sugars. In contrast, vegetables, whole fruits, legumes, nuts and high-quality proteins are much more expensive and, in “food deserts,” often unavailable.

The authors have already taken a bit of a beating about this on Twitter from the agriculturally-literate-intelligentsia. Why?  Because these sentences give the incorrect impression that farm policy is a major contributor to obesity.  That's not saying farm policies aren't inefficient, only that they do not have the effects many people claim they do.

Why would farmers support policies that would make commodities "exceptionally cheap" and thus lower their profits?  Yes, there are some policies that likely increase production beyond what would happen in an un-distorted market, but there are other policies that reduce production.  Take corn, for example, which is the largest agricultural crop in the U.S. in terms of value of production.  The existence of subsided crop insurance subsidies and commodity programs might increase the tendency to produce more than would otherwise be the case, but ethanol policies from the EPA re-direct much of that production to fuel rather than food. Moreover, there are countervailing policies such as the Conservation Reserve Program (CRP), which remove land from production.  In addition, sugar policies push the price of sugar up, not down.  

The authors also point to processed food as another big evil, but in so doing they (correctly) undercut the argument that farm policy is a major culprit.  How so?  Well, for every $1 we spend on food, only about $0.15 results because of the cost of the farm product.  The other 85% of the cost is from transportation, processing, packaging, marketing, retailing, etc.  As a result, changes in farm commodity prices have relatively small impacts on retail prices.  

Fruits and vegetables are indeed more expensive than many commodity crops, but that's because of biology not policy (see more on that here and here).  Here's what I wrote in one of those posts:

why do we grow so much corn, soy, and wheat in the U.S.? A primary answer is that these plants are incredibly efficient at converting solar energy and soil nutrients into calories (they’re the best, really the best). Moreover, these calories are packaged in a form (seeds) that are highly storeable and easily transportable - allowing the calories to be relatively easily transported to different times and to different geographic locations. Contrast these crops with directly-human-edible fruits/vegetables like kale, broccoli, or tomatoes. These plants are poor converters of solar energy to plant-stored energy (i.e., they’re not very calorie dense), and they are not easily storeable or transportable without processing (mainly canning or freezing), which requires energy.

If you don't believe me, there is a long literature by agricultural economists on this subject.  See this book by Julian Alston and Abby Okrent or these papers in American Journal of Agricultural Economics or Journal of Health Economics, the later of which was co-authored with Brad Rickard.  Other papers take entirely different approaches but arrive at the same conclusion.  See this paper in Food Policy by Corey Miller and Keith Coble or this one by Alston, Sumner an Vosti, also in Food Policy.

As for the efficacy of the other policies proposed by Ludwig and Rogoff, I'm skeptical of their efficacy in truly affecting obesity.  See this paper I recently published in Applied Economic Perspectives and Policy or my 2013 book, The Food Police.

Inequalities of Fat Taxes and Thin Subsidies

I was excited to see The Economist ran an article on my paper with Laurent Muller, Anne Lacroix, and Bernard Ruffieux, which appeared in the Economic Journal.  In typical Economist fashion, they didn't mention us by name, but here's their summary of our findings:

The study found that the taxes and subsidies actually widened health and fiscal inequalities. Fat taxes meant the women on lower incomes paid disproportionately more for food—their habits changed less. They preferred to buy food they liked rather than what made nutritional sense. Taxing the food they eat most made the poor poorer.

Subsidies encouraged all income groups to buy more fruit and vegetables. But those on higher incomes proved more responsive and so benefited most. Interestingly, richer folk were also more likely to buy the subsidised healthy food and then spend the savings they had accrued on yet more healthy food. But poorer women, if they responded to lower prices, often used the money saved to buy unhealthy items or something else entirely. Once the nutritional price policies were applied, the average share of budget spent on healthy food actually increased for the better-off.

The Effects of Farm and Food Policy on Obesity in the United States

That's the title of a new book by Julian Alston and Abigail Okrent.  Right now it's only available as an ebook, but the hard copy should be out soon.  Here's the publisher's description.

This book uses an economic framework to examine the consequences of U.S. farm and food policies for obesity, its social costs, and the implications for government policy. Drawing on evidence from economics, public health, nutrition, and medicine, the authors evaluate past and potential future roles of policies such as farm subsidies, public agricultural R&D, food assistance programs, taxes on particular foods (such as sodas) or nutrients (such as fat), food labeling laws, and advertising controls. The findings are mostly negative—it is generally not economic to use farm and food policies as obesity policy—but some food policies that combine incentives and information have potential to make a worthwhile impact. This book is accessible to advanced undergraduate and graduate students across the sciences and social sciences, as well as to decision-makers in the public, private, and not-for-profit sectors.


I had the pleasure of seeing a pre-release copy of the book and provided the following blurb:

That obesity is a serious challenge in America is undeniable. Yet, appropriate policy responses are far less clear. The Effects of Farm and Food Policy and Obesity is a tour de force. Alston and Okrent provide a solid economic framework for thinking about obesity policies, bust myths about the causes of the problem, and offer nuanced solutions. The book is a must read for anyone seriously interested in role of food and agricultural policy in addressing obesity.

Economics and Obesity Policy

The International Journal of Obesity just released a a short review paper I was invited to write, which discusses the economics of policies aimed at reducing obesity. In the paper, I touch on the economic approach for thinking about government intervention in this space and whether there are market failures that would justify intervention.  I then move on to discuss a variety of specific issues that are often discussed in relation to obesity such as farm policy, soda taxes, healthy food subsidies, food assistance programs (and proposed restrictions on them), and information policies. 

Here is the conclusion:

This article presented a somewhat pessimistic view on the ability of government policy to substantively influence obesity prevalence. Obesity is a complicated and multifaceted issue. So too are the effects of anti-obesity policies. One response is to argue for an all-out ‘war’ on obesity. It probably is true that government policy mandating what farms grow, restricting the
supply and type of food to consumers, and controlling prices, offerings and advertisements by food manufacturers could reduce obesity prevalence. But, is this the type of coercive
society in which we would like to live? Society faces very real tradeoffs between economic freedom, technological progress, and obesity prevalence. These sorts of tradeoffs are unfortunate, but they reflect very real constraints to effective economic policy making.

My paper joins several others that critically evaluate anti-obesity policies.

Which other government programs are us fat?

A few days ago, I took on the claim that farm subsidies are making us fat (the answer is most likely "no").  However, there are other government programs that potentially affect food prices - what about those programs?  Have they contributed to the rise in obesity?

A new paper in by Julian Alston, Joanna MacEwan, and Abigail Okrent in Applied Economic Perspectives and Policy asks whether funding for agricultural research and development (R&D) can explain the rise in obesity.  The chain of logic goes like this: there is extensive evidence that funding for agricultural research increases productivity; higher productivity means getting more food using fewer resources; more food means lower food prices; more food at lower prices means more food intake; more food intake leads to obesity.  Ergo, government funding for agricultural research leads to obesity.  

So what did the authors find?  They found that agricultural R&D spending probably did have a modest effect on obesity rates, but that R&D also resulted in enormous benefits to consumers and producers.  The authors write:

Our analysis of historical counterfactuals suggests that it would have been very expensive to have foregone past R&D-induced productivity growth, even if in doing so we were able to reduce obesity and related healthcare expenditures.

And, if we had undone the R&D efforts that led to the food price changes since the 1980s:

This would be a costly reversion; it would cost consumers $65.01 billion, of which only $4.72 billion would be offset by savings in public healthcare costs, to reduce average U.S. adult body weight by 4.85 lbs. This translates to a cost of $55.6 per pound after the savings in public healthcare costs are taken into account.

In summary:

The implication is that agricultural R&D policy is unlikely to be an effective policy instrument for reducing obesity, both because the effects are small and because it takes a very long time, measured in decades, for changes in research spending to have their main effects on commodity prices. Moreover, as our results and others have shown, the opportunity costs of reducing agricultural research spending in the hope of eventually reducing the social costs of obesity would be very high because agricultural research yields a very large social payoff.

Having now discussed the effects of farm subsidies and agricultural research, what about programs like the government-sanctioned check-off programs?  That was the topic of a session at the most recent AAEA meetings in Boston.  Parke Wilde from Tufts and Harry Kaiser from Cornell debated the role of check-off programs and their role in affecting public health and nutrition.  I was unfortunately unable to attend the session, but Parke offered a preview of it on his blog.  I hope to see some research on this topic in the near future.