For your listening pleasure

Check out Gramercy Riffs. They have been described as a "heartbreak/nostalgia pop" band; see other commentary here.

Something fishy about "no evidence"

Searching Google for "no evidence" yields "about 21,300,000" hits. It seems we're keen to deny that there is any empirical support for countless different claims. For example, scientificblogging.com reports that there is "No Evidence For Fish Oil Benefit In Arrhythmias" based on a systematic review just published in BMJ. (Full disclosure: I have previously participated in research on omega-3 fatty acids, however I have no related financial interests.) What does the review itself say?

This is the first systematic review attempting to evaluate whether the protective mechanism of fish oil supplementation is related to a reduction of arrhythmic episodes determined either by a reduction in implantable cardiac defibrillator interventions or a reduction in sudden cardiac death. We found a neutral effect on these two outcomes. The confidence intervals for these outcomes were wide and a beneficial effect up to a 45-48% relative risk reduction cannot be excluded.

To better appreciate this, here's their Figure 2:
Note that of the three studies that looked at the proportion of implanted defibrillators that were triggered, one showed a statistically significant effect in favour of fish oil, and the other two did not show statistically significant effects (one favoured placebo and the other favoured fish oil). Six studies looked at sudden cardiac death in patients taking fish oil compared to those taking placebo. Only one was statistically significant, and it favoured fish oil. Of the five studies that did not show statistically significant effects, two favoured fish oil, and three favoured placebo.

The diamond shapes in the figure show the pooled estimates with their 95% confidence intervals: in each case the diamond overlaps an odds ratio of 1, indicating that the overall effect is not statistically significant. And when there's a non-statistically significant effect, it is common practice to say there is "no evidence". But that can be very misleading! After all, two of the individual studies did show a significant benefit of fish oil. So what's going on? Well, for starters, there's some indication of heterogeneity between the studies (particularly in the case of the defibrillator studies). But it also seems that more large studies are needed: a good deal of the variation in results between the studies may simply be due to the play of chance. Quite substantial benefits of fish oil are entirely plausible: relative risk reductions of as much as 45-48%!

What is "no evidence"?

Consider the figure below:

At the bottom there is a gray axis line with tick marks and a vertical gray line indicating the "null" value (where there is no preference one way or the other). The blue line with arrows at each end represents an infinitely wide confidence interval. This is the most straightforward representation of "no evidence": there is simply no empirical information to indicate what the true effect might be.

But suppose we have a very small sample, that is, one that provides almost no empirical evidence. The figure might become:

The only difference is the blue dot on the confidence interval just a bit to the right of the null line. It represents the point estimate based on a very small amount of empirical information. Of course it could equally well have been on the left hand side (or perhaps directly on the null line). Regardless, the confidence interval is still very wide, so very little can be said about the true effect. With such a wide confidence interval, the location of the point estimate is almost irrelevant.

Finally, suppose that a reasonably large sample is available:

I have left the point estimate at the same place. The confidence interval no longer has arrows on either end and is relatively narrow. However it still overlaps the null line. That means the estimate is not statistically significant. Sometimes this sort of situation is described as showing "no evidence of an effect". But as I noted above, that's quite misleading language. In fact, what this situation shows is indeed evidence—evidence that any effect likely has a magnitude of no more than two tick marks (whatever they represent) on the right hand side of the null line or a magnitude of no more than about a half a tick mark on the left hand side of the null line.

But here's the tricky part: what do those ticks represent? Suppose the axis represents annual cost savings that might result from implementing a certain type of federal government program. If each tick mark represents $1000, then we have estimated that the program will cost at most $500 a year and save at most $2000 a year. In other words, the program has been shown to be effectively revenue neutral: the evidence suggests that the cost/cost-savings of the program will not be important. On the other hand, if each tick mark represents one million dollars, most of us would feel that the jury's just not in yet. A possible cost of $500 a year is a drop in the bucket, but $500,000 a year is something else entirely.

In a way, money is the easiest measure to evaluate like this. Things like safety are much harder. For example, if the evidence suggests that a certain chemical may increase the rate of certain types of cancer, but the findings are not statistically significant, what can we conclude? Can the manufacturer claim that there's "no evidence" the chemical is harmful? Can health activists claim that there's "no evidence" the chemical is safe?

I would argue that the term "no evidence" is inappropriate in either case. The underlying questions remain: what is required in order to conclude that a chemical is harmful or that it is safe? Ultimately there's no getting around the issue of how large a difference (in, for example, cancer rates) has to be in order to be considered important. And that's a rather uncomfortable question.

Fuzzy on the whole "good-bad" thing

Michael Ignatieff, the new leader of Canada's Liberal Party has been described as a political chameleon. Writes Michael Valpy:

But who is Michael Ignatieff really? Is he the pinkish liberal who champions human rights and carries Pierre Trudeau's torch for social justice? Or is he the conservative realist who embraced George W. Bush's attack on Iraq and flirted with the notion that torture could be acceptable?

I wonder if Ignatieff's 2004 book, The Lesser Evil, should instead have been titled Maybe Torture's Like, Ok?

But one thing's for sure—as a reviewer on Amazon.com put it—Ignatieff is "fuzzy on the whole 'good-bad' thing."

For a commentary on torture minus the fuzziness, see this 2003 editorial from the British Medical Journal. The subtitle puts things in focus:

Torture is a form of terrorism:
there are no justifications for it

Michaëlle Jean for President

So our Governor General, Michaëlle Jean acceded to Prime Minister Stephen Harper's request that Canada's parliament be suspended until late January. And the justification ... ?

Well, none was provided. But perhaps it had something to do with Harper's Conservative Party being on the brink of losing control of the government.

Now I don't dispute that the Governor General was acting within her powers. But I do think her powers need some tweaking if parliament can be suspended just to allow the Prime Minister to evade the will of the elected members of parliament. That kind of contempt for democracy smacks of absolutism. Who does the Governor General report to, anyway? Oh, right: the Queen of England!

I'm reminded of some lines in the jingoistic second verse of "God Save the Queen":

O Lord, our God, arise,
Scatter her enemies,
And make them fall.
Confound their politics,
Frustrate their knavish tricks,
On Thee our hopes we fix,
God save us all.

God save us all, indeed. It seems that Canada's politics are the ones being confounded. (I confess, however, that I do admire the rhyming of politics with knavish tricks.)

I wonder if it isn't time that Canada grew up and that the sun set once and for all on the western remnant of the British Empire. It's time we became a republic. Of course a republic needs a President. And to show I hold no grudges, I would like to nominate Michaëlle Jean. But enough already with the proroguing!

Peroguing parliament

I note with alarm that Canada's parliament may soon be perogued!

Update 07Dec2008: Overheard at a party: "We're in prorogatory!"

Express yourself with the Log base 2 virtual fridge

© 2008 Adam Barrowman.

You can't save your poetry, so be sure to do a screen capture. Or just write it down!

Oh m'eye

My daughter has an eye for art:

False idols

The painting below is Golden Calf 2, 1985, by Irving Norman.

A recent post on Massimo Pigliucci's blog Rationally Speaking proposed a "classification of types of commitment, from the most ludicrous to the most defensible". Pigliucci started with "commitment to a symbol", and he didn't pull any punches:

This is the stupidest form of commitment ever invented by human beings. I’m referring to people who “pledge allegiance” to flags, or who worship religious symbols of torture, such as crosses. It seems to me that nationalism and religion in particular are among the worst causes of human misery, and that more generally it is profoundly irrational and highly immoral to “commit” to a symbol for the symbol’s sake. Flag burning, or making sculptures of crucified frogs, while not acts I have ever actually engaged in, ought to be protected and even encouraged forms of free speech.

He followed this with some interesting thoughts on "commitment to an institution" and "commitment to people" before arriving at "commitment to ideas":

Within limits, I think this is actually the most important and rational type of commitment one can make. Ideas like democracy, education, fairness, justice, and so on are actually much more durable than either institutions or individuals. If an idea is good, it remains good under a wide range of circumstances, and it accordingly deserves our steady commitment. Even here, however, commitment should not be absolute and unconditional

But there's a problem here, as commenter J pointed out:

I'm having a somewhat hard time seeing the real difference between the first level (commitment to symbols) and the last (commitment to ideas)!

I noticed you qualified it there, "it is profoundly irrational and highly immoral to “commit” to a symbol for the symbol’s sake". But is there such a thing as committing to a symbol solely for its sake? Isn't a symbol always the embodiment of an idea? There is no symbol without an idea behind it, is there?

I then chimed in:

I agree with J: commitment to a symbol usually means commitment to an underlying idea or set of ideas. For example, to Christians, the cross symbolizes love, redemption, justice, etc. Sacred symbols like the cross are typically the focus of ritual and worship. Note that the English word worship relates to ideas of worthiness and respect, which is, I think, a big part of what religious expression is about.

J goes on to point out that some ideas have associated symbols, "but we never see anyone worshiping those symbols, curiously enough". Perhaps, but consider the idea of materialism, which is widely admired. Its symbols could be said to be the logos of consumer brands, like Mercedes-Benz, Starbucks, Chanel, ... the list is endless.

When people walk around bedecked in corporate logos, perhaps they are expressing a form of worship of materialism.

Pigliucci responded:

I still think there is an important distinction to be made here. Christians, or patriots, get really worked up about their symbols, threatening violence or passing legislation in their defense. The symbol seems to transcend the idea.

And I replied:

Interestingly, this issue comes up in religion itself. The idea of idolatry is at least partly about confusion between symbols (images, objects) and ideas (about the divine). Differing ideas about the proper treatment of symbols have contributed to the divisions between branches of Christianity.

And consider that although we today use the term iconoclast to mean someone who attacks conventional ideas, originally it meant someone who destroyed religious symbols (art in particular).

The crash of symbols

It seems to me that when people treat a symbol as sacred (whether explicitly or implicitly), they are not only expressing a commitment to the ideas represented by the symbol, they are also identifying with it at a deep emotional level. They view an attack on the symbol as a desecration, and more: an assault on their identity.

The symbol par excellence

What is the most ubiquitous and perhaps most potent symbol of all? Language. Consider, for example, the Biblical injunction against taking the Lord's name in vain. Doing so is desecration of a holy symbol.

It seems to me that perhaps the greatest lie ever perpetrated is this one:

Sticks and stones
May break my bones
But words can never hurt me

The human right to peace

Thursday, December 4, internationally renowned peace and justice activist, Senator Douglas Roche, O.C., former Canadian Ambassador to the UN for Disarmament, will speak at a special public meeting in Ottawa. The venue is Southminster United Church, corner of Bank St. and Aylmer Ave., (just South of the Bank St. Bridge over the canal).

His topic will be “The Human Right to Peace”—the title of one of his recently published books. (Incidentally, I looked up some reviews of the book: here and here.)

Twin delusions

Fascination with identical twins goes back a long way: think of the founders of Rome, Romulus and Remus, and the astrological symbol Gemini. Our modern understanding of genetics has given us a scientific perspective on identical twins, and yet it too is accompanied by a mythology.

By virtue of being genetically identical, identical twins would seem to provide an ideal source of evidence concerning the heritability of traits. Since identical twins share physical characteristics, is it not conceivable that they also share traits such as intelligence and personality? There is, however, a fly in the ointment: the influence of the environment in which twins are raised. While eye colour has a purely genetic basis, couldn't intelligence depend on how twins are jointly brought up? There are two ways around this obstacle.

Twins: Take 1

The first depends on a rather unlikely occurrence: identical twins separated at birth. Which brings us, my dear Watson (and Crick) to the curious case of Sir Cyril Burt (1883–1971), an English educational psychologist. In "The Mismeasure of Man", Stephen Jay Gould writes that Burt:

... published several papers that butressed the [claim that IQ is inherited] by citing very high correlation between IQ scores of identical twins raised apart. Burt's study stood out among all others because he had found fifty-three pairs, more than twice the total of any previous attempt.

But perhaps this was too good to be true:

Princeton psychologist Leon Kamin first noted that, while Burt had increased his sample of twins from fewer than twenty to more than fifty in a series of publications, the average correlation between pairs for IQ remained unchanged to the third decimal place—a statistical situation so unlikely that it matches our vernacular definition of impossible.

Gould goes on to review further evidence that Burt faked many of his results. But by the time this came to light, the damage was already done: Burt's studies had influenced British educational policy for decades.

Twins: Take 2

A second way around the impact of environment is to compare identical twins with same-sex fraternal twins. If a trait is inherited, we would expect identical twins (known as monozygotes, MZ) to be more similar than fraternal twins (dizygotes, DZ), irrespective of environmental influences. A particularly disturbing example of this argument is in a 2005 paper titled "Evidence for substantial genetic risk for psychopathy in 7-year-olds" (Viding et al. J. Child Psychol. Psychiatry 46:6, pp 592–597). Measures of psychopathy were reported by teachers for each member of nearly four thousand twin pairs. A child with a high score (the "proband") was then compared with his or her co-twin. The figure below is a hypothetical example, but it qualitatively represents the study findings:
As depicted in the figure, identical co-twins (MZ) were closer to the proband than fraternal twins (DZ). In fact, the authors studied two traits: callous-unemotional (CU) and antisocial behaviour (AB). The reported "remarkably high heritability for CU, and for AB children with CU".

Megan McArdle cited this study (via a summary article) in a recent blog post:

Some years ago, I remember reading Jonathan Kellerman's Savage Spawn, a book on sociopathic children, and how nearly impossible it is to treat them. [...] It's truly heartbreaking: a child who doesn't seem capable of loving its parents, or anyone else. It seems to be mostly genetic, and nearly completely immune to any current treaments.

While I can't comment on the claim that it's "nearly impossible to treat" (though I wonder what the substantive basis for such a claim would be), I do question the claim that it's "mostly genetic". Do identical twins really grow up in the same environment as same-sex fraternal twins? I doubt it. As Lea Winerman wrote in A Second Look at Twin Studies in the April 2004 issue of the American Psychological Association Monitor: "... some research suggests that parents, teachers, peers and others may treat identical twins more similarly than fraternal twins." Winerman provides a balanced review of the continuing controversy about twin studies, raising a number of other problematic assumptions.

Time to move on ...

Back in April I expressed my skepticism about genetic determinism in the context of sex differences. I don't doubt that genetic factors can play an important role in a variety of traits. But the more complex the trait the trickier it is to sort out the relative contributions of genetics and environment. And the more likely it is that our own prejudices will swamp the evidence. We've been down this road before.

Great web apps with strange names

The last couple of years have seen a proliferation of great web applications. And for some reason, the fashion is to give them bizarre names like Loopt, Mobunga, and Lijit. (Any guesses what they do?) The collage of "web 2.0" logos on the left provides plenty of examples (click on the image to link to the website where they provide a huge high-resolution version).

So here are my favorite strangely-named but wonderful web apps:

Jango is a free, customizable internet radio service. The way it works takes a little getting used to, but it's a terrific way to hear lots of great music.


SUMO Paint is an awesome online image editor.


Weebly is a free service that lets you easily create and host a website.


Slinkset lets you create a social news site. For example, I created StatLinks in just a couple of minutes.


Finally, here's a clever web application whose name says it all: MizPee.

The do-not-call fall

Sometimes things take a while to make it to Canada. The nutrition facts label on pre-packaged food was introduced in the U.S. in 1994. Canadians had to wait until 2005 for a similar labeling scheme. When it comes to the scourge of unwanted telemarketing phone calls it's no different. The U.S. National Do Not Call Registry came into effect in 2003. Five years later, Canada is finally getting a do-not-call list. It should be operational this fall (September 30th, so they say).

The bad news (as I see it) is that there are some exemptions. Even if we sign up, we'll still get calls—whether we want them or not—from charities, political parties, polling companies and companies with whom we have existing business relationships.

I can see the argument for allowing charities to make fundraising calls, but I still disagree. When I give to a charity, I want as much of my donation as possible to go to the cause, not to pay for fundraising. I suspect that a lot of money is wasted on competition between charities.

To plug the holes in the do-not-call legislation, Michael Geist has created a free service called iOptOut that provides automatic opt-out notification to exempted organizations. The Canadian Marketing Association (CMA) also has a Do Not Contact Service. It covers mail, telephone, and fax. Note: When the National Do Not Call List comes into effect it will supersede the CMA's telephone service but not its mail service.

Don't call me, I'll call you

At the end of the day, I prefer an opt-in arrangement rather than an opt-out one. And if nobody opts in? Well, I'd say that's just fine.

Consider the U.S. experience:



What do you think? How has the do-not-call system worked in the U.S.? Are the exemptions in the Canadian system warranted?

Paintings by Ottawa artist Aline Coulombe

An artist is a dreamer consenting to dream of the actual world.
—George Santayana

log calculator

My son has written a program to calculate the logarithm using any base. Be careful of splinters!

The log base

of

For more stuff about logarithms see my posts:
log base 2 and double, double toil and trouble. And of course, don't forget Wikipedia.

Scandinavophilately

When I think of SAS, it's usually the Statistical Analysis System I have in mind. But there are about 50 other meanings. (Not everyone likes the word disambiguation, but I think it's helpful in cases like this!)

One meaning of SAS is the Scandinavian Airlines System. I bring this up because my father was a scandinavophile. Below is his hand-drawn map of Greenland.

On the southern part of the West coast of Greenland is a place with the Danish name Søndre Strømfjord (Kangerlussuaq in the Kalaallisut language). If you look closely, it's marked by a little red mark (it's an airplane symbol) on the map about a quarter of the way up from the bottom. Søndre Strømfjord has a fascinating aerospace history that began in 1941 with the establishment of a U.S. air base and has continued right up to the present day.

Hey, it's only 3 hours to the North Pole!


Part of the history of Søndre Strømfjord is described (in rather grandiose language) on the SAS website:

Polar exploration had been something of a Scandinavian specialty and it was no surprise that SAS set about the task of conquering the hostile airspace over the Arctic. It took a special polar navigation system, the heart of which was a polar path gyro, to overcome the problems of flying over the magnetic North Pole.

The first, pioneering transpolar route, between Scandinavia and the U.S. west coast was inaugurated by SAS in November 1954. A SAS DC-6B “Helge Viking” flew from Copenhagen to Los Angeles via Søndre Strømfjord on Greenland and Winnipeg in Canada. The route cut the distance between the two continents by about 1,000 kilometers and was hailed as “the first new commercial route in 1,000 years”

Which brings me back to my father. He was also a stamp collector and had a series of philatelic covers of historic flights involving Greenland. The cover below commemorates the 1954 Helge Viking flight.


Hmm, I wonder what that polar bear is thinking ...

A planet with flowers

People from a planet without flowers would think we must be mad with joy the whole time to have such things about us.
—Iris Murdoch, A Fairly Honourable Defeat

Here are some photos I took this afternoon:

n-Fold

Truth or lies?

Since I've been focusing on lies lately, I couldn't resist the image on the left which I happened on today. Don Asmussen's Bad Reporter cartoon is quite entertaining.

Reflections on deception

As I discussed in my last post, the word "lie" is often used to refer to a broad class of deceptions. But there is much to be said for specificity. I like the following definition, which the Stanford Encyclopedia of Philosophy calls the "the most common definition of lying":

to make a believed-false statement to another person with the intention that that other person believe that statement to be true.

And as I argued a couple of years ago, definitions matter. Someone accused of lying will surely opt for the narrow definition above. The accusation may then actually strengthen their position. If a lie can't in fact be demonstrated, they may appear to be vindicated. It seems to me that politicians often play this game. Indeed the accusation of lying conveniently distracts attention from more important deceptions.

There's a kind of objectivity about lies. With appropriate evidence, only a minimal number of assumptions are required to identify a lie. Children learn this quickly, and graduate from outright lies to distortions. When asked "Did you eat the cookies?" a small child may declare "No, it wasn't me!", all the while wiping the cookie crumbs from their mouth. A slightly older child might evade the question (and thereby avoid lying) by saying "I saw my brother eating some!"

The more sophisticated deceptions that adults practice typically don't include actual lying. It's simply too risky: being caught in a lie leaves one very little room to maneuver, and the likelihood of damage to one's credibility and reputation. Other forms of deception offer far more avenues of escape. Compared to lying, more subtle forms of deception are not nearly so easy to nail down. They often hinge on ambiguous language, evasions, exaggerations, and selective use of evidence.

The stovepipe

Consider, for example, the practice of "stovepiping", in which intelligence operatives are ordered to directly pass raw information that supports a certain conclusion up to the highest political levels. In a 2003 New Yorker piece Seymour Hersh described the practice in the context of "the disparity between the Bush Administration’s prewar assessment of Iraq’s weapons of mass destruction and what has actually been discovered":

The point is not that the President and his senior aides were consciously lying. What was taking place was much more systematic—and potentially just as troublesome. Kenneth Pollack, a former National Security Council expert on Iraq, whose book “The Threatening Storm” generally supported the use of force to remove Saddam Hussein, told me that what the Bush people did was “dismantle the existing filtering process that for fifty years had been preventing the policymakers from getting bad information. They created stovepipes to get the information they wanted directly to the top leadership."

Hersh quotes a former aide to Dick Cheney:

There’s so much intelligence out there that it’s easy to pick and choose your case. It opens things up to cherry-picking.

Lies, damned lies, and deceptions

As everyone knows—thanks to Benjamin Disraeli—there are lies, damned lies, and statistics. I believe the point here is that there are things much worse than lies. Disraeli (a politician) pointed the finger of blame at statistics. And indeed statistics can be used in a misleading way. Even without altering the data (i.e. lying), there are numerous ways to misrepresent the evidence. But this applies much more generally—as Disraeli was no doubt aware. For example, in budgeting a common problem is what is euphemistically called strategic misrepresentation. In the realm of politics, there's the non-denial denial. And in the world of marketing and PR, there's the fake blog, or flog.

Honesty and dishonesty

In the face of so much dishonesty, it may be tempting to retreat into cynicism. I think that would be a mistake. There is far more honesty and integrity in the world than it may appear. But the cacophony of deceit sometimes seems to drown out the quiet decency that is all around us.

Finally, a warning from O. Henry (Rolling Stones, 1912):

There is no well-defined boundary between honesty and dishonesty. The frontiers of one blend with the outside limits of the other, and he who attempts to tread this dangerous ground may be sometimes in one domain and sometimes in the other.

To be honest

People in public relations are sometimes accused of being "paid liars". This misses the point. According to communications consultant Peter O'Malley:

In all instances, on both practical and legal grounds, effective public relations means not lying or defaming. But when perceived or real culpability is high, damage control inherently requires that engaged PR practitioners not volunteer facts they may know which may be true and may even be important to getting at the "truth" of the matter, but the disclosure of which would be harmful to the client's interest.

So lying is out (at least in principle), but that doesn't mean we'll be getting the whole truth. O'Malley continues:

And it frequently requires being steadfast in characterizing a "nearly empty" bottle as being "almost full". We may like to call all this "focused messaging", but in plain language, it means being highly selective in the presentation of information. Ultimately, it may mean being disingenuously mule-headed, and even secretive. In many settings, this may serve the client's interests, but it does not serve to enlighten the public.

Stronger forms of public relations are sometimes termed "spin". As Wikipedia puts it:

In public relations, spin is a usually pejorative term signifying a heavily biased portrayal in one's own favor of an event or situation; it is a "polite" synonym for propaganda. While traditional public relations may also rely on creative presentation of the facts, "spin" often, though not always, implies disingenuous, deceptive and/or highly manipulative tactics.

The Wikipedia entry on propaganda sheds still more light on this:

As opposed to impartially providing information, propaganda in its most basic sense presents information in order to influence its audience. Propaganda often presents facts selectively (thus lying by omission) to encourage a particular synthesis, or gives loaded messages in order to produce an emotional rather than rational response to the information presented.

So the trick isn't to tell lies, it's to carefully cherry-pick facts and use them to "encourage a particular synthesis". William Blake put it well:

A truth that's told with bad intent beats all the lies you can invent.
"Auguries of Innocence," Poems from the Pickering Manuscript

Note that the term "lying by omission" obscures this somewhat. The Wikipedia entry for lie provides this description:

One lies by omission by omitting an important fact, deliberately leaving another person with a misconception. Lying by omission includes failures to correct pre-existing misconceptions. A husband may tell his wife he was out at a store, which is true, but lie by omitting the fact that he also visited his mistress.

But this raises all kinds of difficulties. To what extent is a person responsible for correcting other people's presumed misconceptions? In fact, "lying by omission" is generally not considered to be lying per se but rather part of the broader class of behaviour we call deception.

Follow the money

Selective presentation of facts may not necessarily be deceptive. In our adversarial legal system, lawyers are expected to argue for one side or the other. The hope is that the truth will come out in the wash. Similarly, we expect a company spokesperson to represent the company's interests. Knowing whose interests a person is representing allows us to decide how to weigh the arguments they present.

Experts are a special case. Whether they are scientists, economists, policy specialists, or what have you, we often believe (or hope) that they are relatively unbiased. The bad news is that bias is ubiquitous. The good news is that a great deal of work has been done to try to identify different sources of bias. (See, for example, Wikipedia's list of different types of cognitive bias.) One straightforward source is bias is financial. Experts (and the journalists who quote them) should reveal possible financial conflicts of interest.

We'd also like to believe that media reports are relatively unbiased. Sadly it's not always so. In January of this year, the Toronto Star published an article titled Top Ten Health Scares, "condensed from the American Council on Science and Health's list of medical stories that made us worry unnecessarily in 2007". As I noted in a previous post, the ACSH is an industry front group. Getting their don't-worry-be-happy message into the pages of a major newspaper—not as advertising, but as content—is PR gold. Imagine the article was instead a full-page advertisement, titled "The Chemical Industry Presents the Top Ten Health Scares".

As an article in the PR Watch Newsletter put it:

In examining organizations like ACSH, therefore, the key question is not, "Are they paid liars?" It is more meaningful to simply ask, "Who funds them, and whose interests do they serve?"

By the Way

I just got back from a wonderful couple of weeks on the Camino de Santiago in Spain (and a little bit in France). Here are some photos from the journey. I'm not sure how to summarize the experience and all its dimensions, but I can say that I have some great memories!

Stop worrying and learn to love the chemicals

Well Margaret Wente is at it again. In a column last week titled Yellow duckies and other killers, she claims that "Mothers across Canada have been prostrated by the plastics scare."

It's hard to be a good mother these days. Deadly perils lurk everywhere. Take that yellow bathtub ducky, contaminated with a dangerous substance known as BPA.

But why stop there? Wente proceeds to list other putative hazards: toxic mould, pesticides, perfumes, "death-rays from the sun", walking barefoot in the grass. The message is clear: stop worrying already!

We forget how negligent our own parents were. They gave us naked sunbaths and let us suck on plastic duckies and roll around on pesticide-drenched lawns. It's astonishing how ignorant they were, and how many of us managed to grow up.

Now Margaret Wente is no scientist (what was your first clue?), so she needs an outside authority:

Dr. Elizabeth Whelan is president of the American Council on Science and Health [ACSH], an independent group devoted to accuracy in health reporting. She points out that both BPA and phthalates have been studied intensively for decades. There are no studies - none - that show any link between these substances and harm to people. The basis for the claims of danger are all from studies done on rats, and they don't predict human risk.

According to Media Transparency, ACSH haven't disclosed their corporate donors since the early 1990's, but their 1991 annual report listed each of the following as contributing at least $15,000:

American Cyanamid Company * Anheuser-Busch Foundation * General Electric Foundation * Rollin M. Gerstacker Foundation * ICI Agricultural Products, Inc. * ISK Biotech Corporation * Kraft, Inc. * Monsanto Fund * The NutraSweet Company * John M. Olin Foundation, Inc. * Pfizer, Inc. * Sarah Scaife Foundation Incorporated * The Starr Foundation * Archer Daniels Midland Company * Carnation Company * Ciba-Geigy Corporation * Ethyl Corporation * Exxon Corporation * General Mills, Inc. * Heublein Inc. * Hiram Walker-Allied Vintners * Johnson & Johnson * Kellogg Company * The Esther A. and Joseph Klingenstein Fund, Inc. * Malaysian Palm Oil Promotion Council * National Starch and Chemical Foundation, Inc. * PepsiCo Foundation Inc. * Union Carbide Corporation

The under-$15,000 list continues on, listing all kinds of industrial, pharmaceutical, and food corporations.

Figures don't lie ...

In her April 19th column, Wente quoted an organizations called the Statistical Assessment Service (STATS) who similarly dismiss concerns about BPA. While they don't accept industry money, STATS is funded by a number of the same conservative organizations as ACSH. I think I see a pattern here.

But so what if these organizations get "conservative" funding? An anonymous commenter on my previous post wrote:

Why should the funding source matter? Isn't it the quality of the evidence and the arguments made? Your smear is the equivalent of an ad hominem attack.

My response:

I don't think it's ad hominem. If a medical study was funded by a pharmaceutical company, I'd like to know that. Not that it invalidates the study: as you say, the quality of the evidence and the arguments (analyses) made is centrally important.

So let's have a closer look at the quality of the evidence and arguments in one particular case.

I looked at a recent post on the STATS blog concerning formula- versus breast-feeding. While the author allows that "Yes, there is robust evidence that nursing reduces ear infections [otitis media] and diarrhea", he sets out to discredit claims of a link between formula feeding and diabetes, leukemia, and serious respiratory infections. In the latter case, he writes "The most recent research does not support the contention that formula carries a higher risk," citing a 1995 paper from the Journal of Pediatrics.

Interestingly enough, that study was supported in part by the Mead-Johnson Nutritional Group. Leaving that aside, however, here are some results from the abstract:

In the first year of life the incidence of diarrheal illness among BF [breast fed] infants was half that of FF [formula fed] infants; the percentage with any otitis media was 19% lower and with prolonged episodes (>10 days) was 80% lower in BF compared with FF infants. There were no significant differences in rates of respiratory illness; nearly all cases were mild upper respiratory infections. ... These results indicate that the reduction in morbidity associated with breast-feeding is of sufficient magnitude to be of public health significance.

Sure enough, they didn't find statistically significant differences in rates of respiratory illness. Now an important consideration in statistics is the power to detect differences, which is determined by a number of factors including sample size. So what was the sample size in this study?

... morbidity data were collected by weekly monitoring during the first 2 years of life from matched cohorts of infants who were either breast fed (N = 46) or formula fed (N = 41) until at least 12 months of age.

So there were a total of 87 infants. In their discussion, the authors write:

We did not observe any significant differences in the incidence or prevalence of respiratory illnesses between BF and FF infants. However, the vast majority of episodes were mild upper respiratory illnesses. Previous studies have indicated that the protective effect of breast-feeding is greatest for lower respiratory illnesses. The sample size in our study was not large enough to detect differences in more severe respiratory illnesses.

Blind trust?

Ultimately, we all have to rely on some surrogate measures to judge the quality and trustworthiness of the information we encounter. Our own expertise can only be so broad and we rely on others to help us interpret the world. Oldly enough the words of Ronald Reagan come to mind: "Trust, but verify."

Great expectations

While a baby carriage makes for a good visual, it's a bit ironic. Once the baby is born there are no special parking spots, at least at the supermarket where I took this photo.