Why are economic journal articles so long?

Seriously.

I've been reading a lot of (hard) scientific studies for my current dissertation chapter and it is striking how concise they are. The majority of published articles, at least the ones that I have come across, are typically no more than 4-6 pages in length. The pattern holds especially true for the most prestigious journals like Nature, Science or PNAS.

In contrast, your average economic article is long and getting longer. [Note: New link provided.]

Now you could argue that science journals achieve this feat by simply relegating all of the gritty technical details and discussion to the supplementary materials. And this is true. For a good example, take a look at this article by Estrada et al. (2013).[*] The paper itself is only six pages, while the supplementary material is over 40 pages long. Equally as telling is how similar this supporting information is to the working paper that the final article is apparently based upon.

To be honest, I don't really see how this can be a bad thing. It is primarily the job of the editors and referees to vouch for the technical merits and internal consistency of a published study. Regular readers are mostly interested in the broad context (i.e. significance of the research) and the actual findings. As much as it is important to make the technical details -- and data! -- available to those who want to go through them, the clutter largely detracts from the key messages. I'm also willing to bet good money that many (most?) people currently just skip through the entire mid-section of your typical economics paper anyway, concentrating on the introduction, results and conclusion.

So, is this a weird case of physics envy, where economists feel the need to compensate for lack of quality through quantity? Or does it say something special about the nature of economics, where the limited extent of true experimental data makes methodology more precarious and prone to bias?

Either way, do we really lose anything by making economic journal articles much shorter and saving all the technical details for the supplementary materials?

PS - Yes, I know that most economic journals already reserve a lot of information for the technical appendices. I'd also say that a number of the top journals (e.g. AER) are pleasantly readable -- perhaps surprisingly so for outsiders. But we're still a long way off what the sciences are doing.

UPDATE: It just occurred to me that the frequency of publication plays a reinforcing in all of this. Nature, Science and PNAS are all issued on a weekly basis. The top economic journals, on the other hand, are typically only bi-monthly (at best) or quarterly publications. The higher volume of science publications encourages concise articles for pure reasons of practicality, as well as readability.

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[*] The authors argue that climate data are better viewed as statistical processes that are characterised by structural breaks around a deterministic time trend... i.e. As opposed to non-stationary stochastic processes comprising one or more unit roots. (This is important because it has implications for the ways in which we should analyse climate data from a statistical time-series perspective.) In so doing, they are effectively reliving a similar debate regarding the statistical nature of macroeconomic time-series data, which was ignited by a very famous article by Pierre Perron. Perron happens to be one of the co-authors on the Estrada paper.

Bad science: Paleo diet edition

A while ago, I wrote a post praising the scientific approach that advocates of the paleo diet appeared to be adopting in arguing their case. In particular, the language used by people like Gary Taubes in discussing dietary health seemed to show a keen appreciation for the key principles underpinning the scientific method. This includes separating causation from correlation, controlling for placebo effects and selection bias, etc, etc.

However, apparently not all paleo advocates are such sticklers for good scientific practice. For example, see this blog post by Jacques Rousseau, which skewers a new "occasional study" by Tim Noakes.[*] There is a lengthy follow-up post that also well worth reading when you have time.

The short version is that Noakes is a very prominent sports scientist in South Africa. He also happens to be an extremely vocal proponent of the low-carbohydrate-high-fat (LCHF) paleo diet, having undergone a Damascene conversion in recent years. The occasional study in question was published in the South African Medical Journal and details 127 unsolicited responses that Noakes received from people who have followed his advice in switching over to LCHF. These correspondences tell of all manner of dietary miracles and health wonders that have followed as a result, from substantial weight loss to curing "incurable" diseases like type II diabetes.

The problem with this study should be all-to-obvious to anyone who understands anything about scientific practice -- more on that in a minute.  Furthermore, a lot of people are (rightly) up in arms about how it managed to get through the peer-review process and into the country's flagship medical journal. Cynical observers have not been shy in suggesting that this is almost entirely down to Noakes' status within the local research community and very little to do with the scientific merit of the study itself. (To be fair, I'm not sure that a double blind submission would have been possible in this case.)

Now, Jacques does a very good job in explaining the manifold problems of the study. He also points out that Noakes' position on the necessity of such anecdotal evidence is very inconsistent. (If we had proper, scientifically validated evidence about the benefits of LCHF then we wouldn't require anecdotal evidence on top of that. To argue otherwise is to suggest that the scientific evidence in favour of LFHC is not actually particularly strong.) However, I think some of the commentators actually do a better job of pinpointing exactly why this study does not belong anywhere near a reputable scientific journal. For instance, "Chris" writes:

[...]You could prescribe or promote absolutely anything, and you would see some people benefit. The key point is that the sample you have is self selected from those who benefited enough that they felt the need to contact you. That is likely to be a small number of the total number of people who did indeed benefit. And we have no idea what proportion of the total number of people to have tried LCHF those people are. The fact that there are 127 people who've shown a benefit is evidence of one thing, and one thing only: those people's ability to write you an email. Can you tell me exactly what their dietary regimes were, down to the last macronutrient? Can you assure me that the change in their diet was not simply a catalyst for them to become more active, thus they expended more energy? Can you tell me that there were no other outside influences that could potentially act as a confounding variable? You can't, and you say so yourself in the article. Which begs the question of why did it get published? If we can't say anything other than these people got amazing results and said they were on LCHF then what exactly can we say?[...]

Emphasis mine. A follow-up contribution by another commentator (who was actually involved in one of the cases that Noakes cites) is equally worth reading here.

To underscore something that Jacques and many of his commentators try to make abundantly clear; criticism of this particular study does not amount to criticisms of LCHF in of itself. The outcry is entirely about sloppy scientific reasoning and misuse (absence?) of the scientific method. Proponents of LCHF and other paleo-style diets may well be correct in identifying the causes of our modern dietary ills. I personally know more than a few people who credit it with helping them to shed weight and improve their overall sense of well-being. On the other hand, I can say exactly the same thing about friends who have converted to veganism. (You see the problem with anecdotal evidence!)

To conclude, if paleo advocates want to maintain scientific credibility, they need to distance themselves from this type of research. At the very least, they should not try to defend it.
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[*] You may recall that I actually mentioned Prof. Noakes at the beginning of my previous post. Rousseau is a senior lecturer at the University of Cape Town, whom it should be said took me for an introductory philosophy and business ethics course during my undergrad.

Advocacy and climate research

The latest furore to erupt in the climate blogosphere concerns whether climate scientists undermine their credibility by engaging in advocacy? (For some responses, see James Annan, Gretchen Goldman and HB&H.)

As it happens, I recently wrote a term-paper on this exact issue for my philosophy of science class. I've decided to make it available here for those who are interested in this debate!

To summarise, I don't see anything inherently wrong with scientists engaging in political advocacy, as long as they are explicit in their intentions... and the scope of their expertise. (E.g. I often see physical scientists make strong pronouncements about economic matters and that makes me uncomfortable.) One climate scientist whom I feel always struck a good balance on these issues and quote in my term-paper is the late Stephen Schneider. To channel Schneider: Our response to climate change must be underpinned by scientific facts, but it should ultimately also be reflective of society's value judgements -- including those of our scientists.

Some brief points/caveats:

• This was a “pass/fail” essay, aimed at gaining admission to sit the exam, and I hope that you’ll evaluate the material accordingly. That said, the emphasis on citations and quotations probably means that it provides a good overview of the issues.
• Apart from scientists working on the physical basis for climate change, I also tried to pay special attention to the role of economists. The Stern Review, which many people regard as the archetypal blend of economics and advocacy, therefore comes in for special attention.

Click to read the term-paper.

UPDATE: I've just finished listening to a very interesting discussion between the climate scientists, Gavin Schmidt, Richard Betts and Judith Curry, on this precise topic. I am again struck by something that was very clear to me whilst researching my essay: The various sides all seem to agree on the principles (i.e. being open about one’s area of expertise and clear on your value judgements when advocating for policy). The real sticking point appears to be one of application.

I, for one, welcome our new technocratic, environmentalist, socialist overlords

Any group that successfully manages to perpetrate a hoax involving tens of thousands of individuals from all over the world... would sure be able to elect a politburo of unimagined efficiency.

Ninety-seven percent agreement collusion conspiracy among climate scientists? One can only imagine how effortlessly they will get the trains to run on time, or tame the business cycle.

The future never looked so bright.

[Note to self: File under right-wing paradoxes.]

Climate science is pseudoscience(?)

So says Ivo Vegter in his latest column, calling up the spirit of Karl Popper.

I drop by in several places in the comments, saying that this pretty much utter nonsense according to any reasonable definition of the falsifiability criteria. For example:

[...]As it happens, Ivo has also beautifully misconstrued the application of Popper's insights, by consistently conflating the actual science with the response to that science by various parties.

[...]At its heart, falsification is about using an underlying set of theories to make predictions that can be tested against the relevant evidence. The theory of (man-made) climate change satisfies the falsifiability criteria across multiple dimensions. The fundamental pretexts of climate science are rooted in physics that has been understood and tested since the early contributions of Fourier, Tyndall and Arrenhuis in the nineteenth century. For their part, modern day climate models absolutely meet the Popperian standards. Not only do they forecast how climate phenomena will evolve under conditions of continued emissions, but (crucially) they have been extremely successful in hindcasting previous changes to the climate. Indeed, this accurate replication of past events is how they are selected in the first place…

As part of his reply to this comment, Ivo made the strange assertion that the ability to hindcast models is weakened by the fact that these models can be "tweaked" to accurately match the observed data. I respond:

How is it a case against climate scientists that they were able to benchmark their theories against against a historic record with "perfect hindsight"? Speaking as someone with a fairly considerable amount of scientific training, that actually sounds pretty ideal. Models were back-tested, refined and then discarded in favour of ones that better fit the data... pretty much in exact accordance with the scientific method.

For the record, I am well aware that Popper's falsification doctrine is not without its problems. Still, and at the very least, if someone is going to invoke his authority to make specific claims, then they should at least make sure they are accurate within that framework.

UPDATE: Oh God, it gets worse. Someone responds to me with the immortal line: "I have not done the research but from my own basic calculations..." *headvice*

UPDATE 2: See this excellent 2005 post by NASA's Gavin Schmidt: Is Climate Modelling Science? It concludes: "So, in summary, the model results are compared to data, and if there is a mismatch, both the data and the models are re-examined. Sometimes the models can be improved, sometimes the data was mis-interpreted. Every time this happens and we get improved matches between them, we have a little more confidence in their projections for the future, and we go out and look for better tests. That is in fact pretty close to the textbook definition of science."

Review - Extreme Environment (Ivo Vegter)

Extreme Environment (hereafter EE) is a book written by South African journalist, Ivo Vegter. I have mentioned Vegter before on this blog and he generously arranged for me to be sent a free copy of EE after I offered to review it in an online discussion. Given this, and seeing as some of other reviews that I have read are disappointingly superficial, I decided to provide a chapter-by-chapter overview and criticism. I hope that you'll excuse the subsequent length of this post in exchange for some added thoroughness. (If not, a condensed version of this review can be found here.)

The major premise of EE is straightforward: Environmentalists are guilty of making grossly exaggerated claims and the green movement should in general be regarded with extreme scepticism. I fully endorse the more measured observation of the book jacket, which is that we should be just as cautious of the emotive rhetoric of environmentalists, as we are of corporate spin. EE expands on this dictum with varying degrees of success and some parts of the book are undoubtedly more convincing (and fairly presented) than others. It should be said that Vegter is not immune to moments of unfounded hyperbole himself, stating as early on as page 3 that the car could not have been invented in today's world, because it "would never have passed modern safety and environmental rules". (Talk about exaggeration!)

Libertarianism and the paleo diet - Natural or strange bedfellows?

I want follow up on the previous post by making a side observation on the paleo diet's marked popularity within libertarian circles -- especially anarcho-capitalists. Certainly, prominent libertarians like Lew Rockwell, Tom Woods and even Russ Roberts have gone "primal" in a very public sense.

Now, sure, this makes sense at the superficial level: It probably comes very naturally to many libertarians that they reject government-endorsed advice, take pride in swimming against the tide of mainstream thought, and so forth. Indeed, here is an article from LRC that openly flaunts the "ideological parallels" that underpin the libertarian-paleo connection. (Thanks Google!)

However, doing something simply because it feels "familiar" is likely to produce counterproductive results sooner rather than later. This is particularly likely to be true when it comes to endorsing heterodox thinking across unrelated topics.[*] After all, there's a reason why certain ideas tend to emerge as dominant over time: They explain the world around us better than the competing paradigms. (Obviously, this can change as we gain more knowledge. Science is a process after all and not an end result.)

More fundamentally, it seems to me that the underlying scientific approach of the paleo movement -- as outlined by Gary Taubes at least -- is at odds with much of what characterizes libertarian economic thought of the Mises.org variety. I've had my say about the dangers of extreme a priorism before and still consider the rejection of empirical testing by some Austrians to be a completely nonsensical dead end. Indeed, the a prioristic approach is antithetical to the empirically-based scientific approach that Taubes so strongly advocates.

Given his popularity among these groups, I wonder what Taubes makes of this?

[*] Rockwell, in particular, seems prone to indulging just about every crank,conspiratorial, anti-science theory around. (They're all there, by the way. HIV/AIDS, evolution versus creationism, vaccines and autism, climate change... Even David Icke, alien technology and unlimited energy!)

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Speaking of libertarian-based economic research, a good example of why experimental design is so important can be found by looking at Selgin, Lastrape and White's (2010) much-circulated paper, Has the Fed has been a failure?. The study itself is a great piece of historical writing that makes an important contribution to the literature. It also uses some fairly advanced empirical techniques such as GARCH time-series modelling. However, SLW don't provide a compelling counterfactual and, as such, their work can at best be described as a "pre-post" evaluation. Despite some overzealous reviews in libertarian circles then, this study was never meant to provide a definitive answer to the question that it asked. To their credit, SLW actually emphasize right at the outset (p. 1):

These findings do not prove that any particular alternative to the Fed would in fact have delivered superior outcomes: to reach such a conclusion would require a counterfactual exercise too ambitious to fall within the scope of what is intended as a preliminary survey. The findings do, however, suggest that the need for a systematic exploration of alternatives to the established monetary system, involving the necessary counterfactual exercises, is no less pressing today than it was a century ago. 

UPDATE: Dan Kuehn weighs in with some thoughts here.  He's not completely convinced that SLW heed their own warning...

The language of science: Paleo edition

I've developed an armchair interest in the so-called "paleo" diet. Among other things, my curiosity was piqued when Tim Noakes -- one of South Africa's most respected international experts in his chosen field of sports science -- came out with a series of very public endorsements... In the process, disavowing views that he had held and promoted for the bulk of his professional career.

"Hey, if it worked for Raquel Welch..."

What really makes me think that this paleo thing is at least worth considering, however, is the language that prominent paleos use when talking about the science underlying nutritional advice. A good example of this can be found in a column by Gary Taubes that was written in response to a much-publicized study by Willett et al. (2012), which purports to show that "eating red meat is associated with a sharply increased risk of death from cancer and heart disease". (HT: A bunch of people.) Taubes is a science writer and, near as I can tell, the intellectual popularizer of the paleo movement. Here he makes some great comments about what characterizes good scientific research:

Science is ultimately about establishing cause and effect. It’s not about guessing. You come up with a hypothesis — force x causes observation y — and then you do your best to prove that it’s wrong. If you can’t, you tentatively accept the possibility that your hypothesis was right. [...]Here’s Karl Popper saying the same thing: “The method of science is the method of bold conjectures and ingenious and severe attempts to refute them.” The bold conjectures, the hypotheses, making the observations that lead to your conjectures… that’s the easy part. The critical or rectifying episode, which is to say, the ingenious and severe attempts to refute your conjectures, is the hard part. Anyone can make a bold conjecture. (Here’s one: space aliens cause heart disease.) Making the observations and crafting them into a hypothesis is easy. Testing them ingeniously and severely to see if they’re right is the rest of the job — say 99 percent of the job of doing science, of being a scientist. 

This should all be drawing nods of approval from anyone trained in the scientific method... say, an economist interested in applied research (pick me!). Gathering a lot of data and observing correlations is only the start. What we really have to do is isolate causal effects and, crucially, establish a reasonable counterfactual. Taubes goes on to critique the Willett et al. study by describing how "associative" relationships are only good for generating hypotheses (i.e. about the causality of those relationships), which must then be tested using experimental settings. Willett and co. apparently don't concern themselves with this vital last step; hence the criticism.

In his article, Taubes concentrates on randomized controlled trials (RCTs), which are the design setting of choice for conducting medical experiments. Unfortunately, carrying out a meaningful experiment in an economic setting can be even more complicated. All too often, we simply aren't able to control for all the relevant factors, or simulate activity within an economy as and when we would want. That means that RCTs are pretty much off the table from the get-go.

Nevertheless, the good news is that empirical researchers have developed some powerful alternatives in the absence of the "laboratory" ideal. We use natural experiments, instrumental variables, difference-in-differences, and other study designs to simulate the laboratory setting and randomize treatment effects. Using these approaches helps us to be reasonably confident in answering many important economic and policy questions.[*] Say, does a minimum wage increase unemployment? (Much to my own surprise, the answer appears to be not really.) Or, how does crime respond to an increased police presence? (Well, according to this excellent study, a 10 percent increase in the police activity of London boroughs brought about a 3 percent drop in crime rates.)  If you click on the above links, you'll find an in-depth discussion of the particular circumstances and methodologies that allowed the researchers to treat their studies as experimental settings. These are just two examples, but they provide valuable insight into how good empirical economics is conducted in practice.

Of course, it should also be noted that economists and other social scientists are increasingly reliant on approaches that mimic the laboratory settings of natural scientists. Two of the most obvious candidates being experimental economics and field experiments. However, my main point in the above paragraph is about how we can still establish causation in the absence of such idealised, controlled settings.

Going back to the paleo diet, I'm still fairly agnostic about the whole thing despite my curiosity.[**]  I certainly don't know enough at this stage to confidently say whether Gary Taubes and co. are fundamentally correct in their views about nutrition. For all I know, the evidence may not be nearly as compelling as they make out. They may even be misrepresenting the views and research efforts of mainstream nutritional experts. However, I do know that Taubes talks about science in a way that makes sense to me. At the very least, that makes me think that he is someone worth listening to.
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[*] Yes, it is true that definitive answers to some major economic questions remain more elusive. Ideology plays a big role as well, but the lack of an experimental setting partly explains why economists disagree on, say, how effective a stimulus package will be in reducing unemployment. 
[**] As my cunning nom de plume will testify to, dietary concerns are not high on my list of priorities. I don't feel particularly compelled to change my eating habits as of yet.

Chief EU science adviser on GMO

Scottish microbiologist Anne Glover is the recently appointed chief science adviser to the EU. The below excerpt concerning GMO is taken from an interview that she gave last month.

She makes three major points: (1) There is a fundamental need for a profit-driven agri-business, (2) Resistance to GMO is driven by emotion rather than any kind of scientific evidence, and (3) Anti-GMO lobby groups are partially to blame for the monopoly power that they so vehemently claim to oppose.

In terms of food security and safety – where do you stand on genetically modified products and what do you think of the EU’s rather dismissive stance to GM to date? 

“In my own area of science, molecular biology, I have used the GM technology for most of my research career and very helpful it has been in generating understanding about how biological and environmental systems work. So I know the power of the technology and the regulations we adopt in order to use it are very sensible and appropriate. I can also see that healthcare and our understanding of diseases has been revolutionised. There has been an unparalleled acceleration of our knowledge generation through the use of GM, which is a fantastic thing. 

“But people in Europe are anxious about the use of GM crops or animals and I have a concern about that because I don’t see the evidence base suggesting that there is substantial risk associated with it. Indeed, you could look at North America where they have been doing an experiment on our behalf for the last 15 years by growing and eating GM crops – and I don’t see over that period of time what negative impact it has had. There is a huge body of evidence, rightly so, looking at the risk of GM. People will ask me: ‘Is there no risk in eating GM crops?’ Well, of course, I would never say that as I am a scientist. What I would say is that whatever you eat for dinner this evening, there is a risk in eating that. There is risk associated with conventional agriculture, organic agriculture, any form of agriculture. 

“Agriculture has a big impact on our environment. The act of fertilising fields reduces the microbial diversity in the soil, but we don’t think that it has any long-term effects. We think it is something we need to do. There are implications for climate change and water spoilage issues so we need to do that with care. So around GM, let us examine the evidence. It doesn’t support the restricted activity in this area that we see. 

“People may say that it is just big business that is making money out of this, but I can’t help thinking that is the job of big business. It is a capitalist system we work in – energy companies make money, transport companies make money. So do agricultural companies. I wish there was a better debate around GM, based on evidence and not emotion. And I wish we could look at risk versus reward. Some farmers say that if we introduce these particular types of GM seeds, then we are tied in to using particular chemicals to manage our crops. They don’t like that because they feel it is a monopoly to a particular company and they are uncomfortable about that.” 

But isn’t that part of the problem, these allegations that a small number of firms have a monopoly in the GM market? 

“Possibly, the reason that [monopoly power] has happened is because of all the restrictions on GM. If I was running a small seed company, it is not an area I would be getting into because I couldn’t afford to do it. The lobbyists and pressure groups have almost been responsible for it by causing this withdrawal from evidence and this acceptance of the emotional argument. It really is not fair to use terms such as ‘Frankenstein foods’. We should be a bit more cautious in Europe here. By turning our backs on the evidence, there is a question over whether we are still going to be as competitive. We need to seriously look at GM crops when we tackle to the global problem of climate change and being able to feed the population of the world. It links into food security as well and we do need to think about that.”

Science and distortion

Below is a video of the late climate scientist, Stephen Schneider. Please watch it and tell me that scientists are the ones trying to polarize this debate and selectively feed us alarmist harbingers of doom. Specifically note Schneider's comment at the 3:35 mark on the false dichotomies, "end of the world" and "good for you".

I see (environmental) economists as making meaningful contributions to this project as well. Cutting through the extreme and distortionist views, so that we can finally settle on some sensible solutions. At times that seems too much to hope for, but every skeptic could do with an optimistic streak...



UPDATE: From 6:04, Schneider provides a great summary of the role that risk management plays in this whole climate debate. I'd refer readers to this post, where I make very similar observations on risk probabilities and insurance decisions.

Avoiding hypocrisy on the big issues

Think of an important environmental issue. Now imagine that there is a large body of scientific research, underpinned by peer-reviewed literature, which has arrived at a broad consensus regarding the relative risks that this issue poses to both the natural ecosystem and human well-being. Standing against this majority scientific position is a stark group of contrarians. They do not have much (if anything) in the way of peer-reviewed science to support their arguments, but instead point to controversial studies by partisan think-tanks and fringe researchers. Further, they invoke a number of conspiracy theories to explain why their position has been marginalised to a scientific minority and yet, ironically, they enjoy significant public support of an almost religious zeal. To be sure, the contrarians certainly aren't adverse to appealing to people's religious sensitivities as way of convincing others of their arguments...

"Yes, OKAY", you're telling yourself, "I know all about climate change scepticism. Get to the point." Except I'm not talking about climate change. I'm talking about genetically modified organisms (GMOs).

Genetically enhanced?

The climate debate and the GMO debate have eerie parallels. Certainly, both are highly polarising issues, which present a myriad of conflicting "facts" to anyone wishing to form an educated opinion on the subject(s). You can spend weeks... months... lost in the dark recesses of the internet trying to disentangle fact from fiction, whole truths from verisimilitude, and legitimate concern from moonbeam conspiracy theory.

When it comes to potentially confusing subjects like these, I believe that we should always make it our first priority to consult the relevant scientific literature. What better way to start addressing a topic than by referring to the qualified experts who have studied these matters in depth, subject to rigorous cross-examination by their peers? This is how we truly weed out the good ideas from bad. In its best form, peer review doesn't appeal to a priori beliefs or care for ideological predispositions. What matters is that you can design and carry out a study (or present a theory) according to accepted scientific standards, in a manner that can be replicated and/or tested by others. The strongest theories survive, while the weak are discarded. Indeed, that's the beauty of peer review; it acts as self-correcting and self-regulating mechanism.

But here's the rub: There is a tremendous inconsistency in the way that people use peer review to approach the respective issues of climate change and GMOs. Since my post here is directed at "environmentalists" as much as anyone else, let me use them as an example.

An environmentalist will happily cite the leading scientific journals, the IPCC and other major scientific bodies in defending his/her position on climate change -- presumably that it is i) happening, ii) driven by human activity, and iii) will bring negative consequences in the absence of strong mitigating action. To all this, I say, "rightly so". However, change the subject to genetically engineered crops, and suddenly those rules go out the window. The selfsame environmental organisations that invoke the most respected scientific bodies to confront climate sceptics, all but ignore what these organisations have to say about GMOs. If that sounds like an unsubstantiated generalisation, have a look for yourself: Greenpeace, Friends of the Earth, etc... are all remarkably consistent in their inconsistency. To be honest, it's disappointing to see just how few exceptions there are to this trend. I realise that people tend to seal themselves off to evidence that isn't congenial to their world view, but we owe it to ourselves to face facts. Speaking of which, let's consider some of the common charges laid against genetically engineered food...

1) GMO crops are dangerous to our health
Um, no. Since their formal approval and introduction into the American marketplace in 1996 and elsewhere, GMO products have been consumed by hundreds of millions of people. To date, not a single substantiated case of human illness or harm has been documented. Nada... not one. Consistent with this, numerous scientific articles published in leading medical journals have have upheld the notion that authorised GMO crops are safe for human consumption. Claims to the contrary have been rejected by reputable journals precisely because they fail to live up to scientific scrutiny.[*] And, of course, there's a functional benefit specific to genetically engineered crops that somehow keeps getting overlooked in this debate: They can be made to produce additional vitamins and nutrients, which are otherwise lacking in certain staples, and thus improve human health. (E.g. The so-called "Golden Rice", which has been biofortified with provitamin A and thus helps to ward off a deficiency in this important vitamin. Another example, virtually all insulin used to treat diabetes nowadays is produced using GMO processes.)

2) GMO crops are bad for the environment
Again, the evidence suggests quite the opposite. The introduction of GMO crops has generally enabled farmers to reduce their reliance on pesticides and herbicides, or allowed them to use less harmful chemicals (e.g. glyphosate). Using herbicide-tolerant crops has also meant that farmers have had to rely less on tilling the soil as a means of controlling weeds. "No-till farming" is good for the environment in the sense that it helps to prevent soil erosion and rainwater runoff. This not only reduces the loss of important nutrients in the soil, but also means that water quality is improved since less chemicals ultimately end up in the waterway.

3) GMO crops have reduced yields and they are more expensive
Despite the claims of many anti-GMO campaigners, this too remains an unproven accusation. Indeed, according to some of the most extensive studies on the matter, GMO crops have been shown to have lower production costs relative to conventional methods, as well as higher output and other extra conveniences. More importantly, these benefits have generally outweighed the higher costs of the engineered seeds in places like the United States.

Before concluding, let me attempt to pre-empt criticism of this post with two caveats:

First, I am by no means suggesting that peer review or our leading scientific bodies are infallible. Certainly, there are well understood problems associated with group-think (or even article suppression and qualification masturbation), which may undermine the process. Just as a majority position does not necessarily constitute an unassailable truth, so we should not -- to channel Richard Horton -- confuse scientific "acceptability" with "validity". However, while peer review is subject to occasional bouts of subversion, it remains far superior to the alternatives. (A blogosphere free for all? No thanks...) Again, I refer to the self-regulating nature of scientific review. Call it the market economist in me, but I find it incredulous that an unsound scientific theory could persist at the expense of a better alternative for very long. In any case, if you chide people for not following the scientific consensus on one topic, it behooves you stick to these same principles on others.

Second, beyond the issues of human and environmental health that I focus on here, there may be other legitimate reasons to oppose the dissemination of GMO crops. I like organic products as much as the next relatively well-to-do Westerner, while I've had my say about animal cruelty before. Further, potential control of food chains by a small number of multinationals through patented crop biotechnology seems to me to be a reasonable concern, deserving the standard anti-trust treatment. I also believe that it's crucial not to collapse the feed-the-world movement into some purely technological debate. As Amartya Sen eloquently argued three decades ago in Poverty and Famines, access to food is much more a complex mix of economics, social and political factors than simply a matter of food production and availability. Indeed, hunger continues to persist in many regions that have bountiful harvests. Agricultural innovation is a wonderful thing (read Norman Borlaug), but technological solutions are not necessarily a panacea for problems of socio-economic origin. Still... These are distinct issues from the scientific aspects that I have discussed above (i.e. human health and environmental safety). If opponents of GM want to preserve their credibility, then they need to separate legitimate concerns from the unsubstantiated, discarding the latter in the absence of credible evidence.

THOUGHT FOR THE DAY: What's good for the goose, is good for the gander. Being concerned about the environment and human health doesn't mean that you can have it both ways, choosing to invoke scientific evidence when and where it is congenial to your position. Those of us who think that climate change is a real issue deserving meaningful action rightly point towards the peer-reviewed science as a first stop for informing our opinions. We would do well to do the same for other contentious issues, such as GMOs.

[*] The most  famous example being the highly-charged Puszstai Affair, in which a controversial study by the eponymous researcher was first published and repudiated by the medical journal, The Lancet. That people may feel (justifiably?) dismayed at Pusztai and his co-author's subsequent treatment by the scientific establishment does not detract from the very real flaws in his study. For instance, his strange decision to use a non-commercially available GMO crop to pass negative judgement on GMO crops in general. Just to be clear, he created a potato crop (expressing a protein toxin derived from a toxic plant), which had never been approved for human consumption by any government agency. He then fed this to rats and made an assessment of how much damage it caused to their stomachs (as compared to normal potatoes where the same toxin was independently added). As Sir Robert May sardonically observed: "If you mix cyanide with vermouth in a cocktail and find that it is not good for you, I don't draw sweeping conclusions that you should ban all mixed drinks."


For those looking for references, some suggestions for further reading are under the fold: