A non-profit, non-partisan organization

In the April 19th edition of the Globe and Mail ("Canada's National Newspaper") columnist Maragaret Wente had a piece titled "The great plastics panic".

Wente reports that at an elementary school near where she lives, plastic water bottles have been "banished":

The kids know what's at stake. Plastic is death! At home, their anxious parents have stopped microwaving with plastic wrap. They've thrown out their plastic baby bottles and replaced them with ones made of glass. Leading retailers ... have banished plastic containers, baby bottles, sippy cups and pacifiers containing one offending chemical from the shelves. No wonder. A barrage of media reports have warned that the chemical in question - bisphenol A, or BPA - may be linked to breast and uterine cancer as well as lowered sperm count, early-onset puberty, obesity, hyperactivity, miscarriages, diabetes and other horrors.

"So," she asks, "how worried should you be?"

"On my list of a thousand things to worry about, BPA would rank about 892nd," says Trevor Butterworth, who's with an independent outfit called STATS (for Statistical Assessment Service). STATS is a non-profit, non-partisan U.S. group that analyzes the use and abuse of science and statistics in the media.

Although Butterworth's 892/1000 is obviously a rhetorical device, it still gets across the message there's nothing much to worry about. But there's another message: this is a quantitative guy! He works for an organization called the Statistical Assessment Service and accordingly he slings around numbers like nobody's business.

When I read this, I headed to the internet to check out this organization. Well, they have a pretty slick website. They describe themselves like this:

Since its founding in 1994, the non-profit, non-partisan Statistical Assessment Service (STATS) has become a much-valued resource on the use and abuse of science and statistics in the media. Our goals are to correct scientific misinformation in the media resulting from bad science, politics, or a simple lack of information or knowledge; and to act as a resource for journalists and policy makers on major scientific issues and controversies.

As a mark of our success, STATS' work has been featured on NBC's "Nightly News," "The NewsHour with Jim Lehrer" and ABC's "20/20" - and in print by The New York Times, Wall Street Journal, Washington Post, US News and World Report, New Scientist, New England Journal of Medicine, and many other publications.

Furthermore, "In 2004, we became an affiliate of George Mason University in Virginia." Pretty impressive.

But how is the organization funded?

STATS is a non-profit, nonpartisan organization that relies on philanthropic donations to support its operations. We do not take money from industry or industry-related groups.

And here, I must admit, I stopped. After all, I had read that STATS is:

• non-profit and non-partisan
  
• "independent"
  
• affiliated with a public university
  
• not funded by industry or industry-related groups
  
• "a much-valued resource on the use and abuse of science and statistics in the media"
  
• getting their work into the New England Journal of Medicine and New Scientist
  

I proceeded to read the rest of Margaret Wente's article. Butterworth's viewpoint was presented a number of times:

Mr. Butterworth maintains that most of the media have been reporting only one side of the story - the side that's driven by a handful of activist scientists and advocacy groups, such as Environmental Defence. Independent assessments conducted by food safety authorities in Europe and Japan, as well as various other risk assessments, have found no basis for the BPA scare. "We've had five major academic independent evaluations of the BPA risk over last two or three years, and they all keep saying the same thing," says Mr. Butterworth. "But they never get reported."

And what about the evidence from animal studies?

"The biological pathways in rats and people are different," notes Mr. Butterworth.

And the final word goes to ... Mr. Butterworth:

"Letting your child outside the door to breathe in exhaust fumes is more risky than letting them drink from plastic bottles," says Mr. Butterworth. He suggests if you're really worried about plastic, give up plastic bags. They suffocate 25 children a year.

Hmmm ... so maybe BPA is not so bad after all.

Uh, not quite ...

Just the other day I got some new insight into the Statistical Assessment Service, thanks to Wikipedia. (I wonder why I missed this the first time round.) Their entry about STATS includes a section on funding:

While the STATS website does not describe its funding sources, STATS is funded by a variety of conservative organizations, including Richard Mellon Scaife's Carthage Foundation, the Sarah Scaife Foundation, the Earhart Foundation, John M. Olin Foundation and the Castle Rock Foundation.

In the United States, funding information is available from the tax returns of 501(c)(3) nonprofit organisations. The information above was collated by Media Transparency. Another organization that looks into media manipulation is SourceWatch, who write:

STATS is a 501(c)3 non-profit organisation but its 2006 annual return to the Internal Revenue Service states that "salary costs for the organization are shared with the Center for Media and Public Affairs. CMPA ... reports the salary costs and files payroll reports under its tax identification number. DCFC is a related organization."[1] (It is not clear what "DCFC" refers to). The report also states that the relationship between STATS and CMPA is one of "common control".[2] Since STATS shares the offices (in the pricey "K Street" lobbying district of Washington) and staff of CMPA, it should be considered as a front, rather than a subsidiary or spin-off.

The Center for Media and Public Affairs is a topic in its own right (see here, here, and here). In 2001 some of the people involved in STATS and CMPA published a book called It Ain't Necessarily So. This review from Salon.com concludes:

A fair review of the state of science journalism is always welcome, but this cleverly disguised example of corporate propaganda isn't it.

Up Front?

The staff list of the Statistical Assessment Service is interesting. The president is S. Robert Lichter (one of the authors of "It Ain't Necessarily So"), who has been the DeWitt Wallace Chair in Mass Communications at the American Enterprise Institute and paid consultant to Fox News. There is a PhD economist and a PhD mathematician. These presumably constitute the core of the analytical team. The executive director is an MBA. And there are two journalists, one of whom is Trevor Butterworth.

Butterworth has no scientific training to speak of (rather, his training is in philosophy and intellectual history). Yet he makes quite strong statements about BPA. Consider this paragraph from Wente's column:

Does this mean BPA is completely off the hook? No. Lots of people think it needs more study. "The possibility that human development may be altered by bisphenol A at current exposure levels cannot be dismissed," said an important U.S. toxicology report this week. Some media stories billed this statement as a five-alarm fire. But as Mr. Butterworth says: "It's a very mild caution. Essentially, it says there is possibility there may be some effects, but we need more research."

Presumably someone with scientific training came to this conclusion and Butterworth is simply repeating it. But if Butterworth is simply a talking head, why is Wente not going to the source?

Toxic?

I started out wondering about the toxicity of BPA, and I still am. But along the way, I bumped into a different toxin altogether. So let's see what an Angry Toxicologist has to say about this (and see Butterworth's extensive comments in response).

Update: It turns out that in 2002, the Fraser Institute (a conservative think tank based in Canada) launched CANSTATS, clearly using STATS as a model. (By the way, the Canadian government's official statistics agency, Statistics Canada, is commonly referred to as StatsCan.) It seems that CANSTATS is no longer operating, but while it did it employed some familiar tactics.

The memory of a moment of happiness

The painting is by Ottawa artist Patty Woodyard (pwoodyard@primus.ca). And the title of this post is from Song of The Flower by Khalil Gibran:

I am a kind word uttered and repeated
By the voice of Nature;
I am a star fallen from the
Blue tent upon the green carpet.
I am the daughter of the elements
With whom Winter conceived;
To whom Spring gave birth; I was
Reared in the lap of Summer and I
Slept in the bed of Autumn.

At dawn I unite with the breeze
To announce the coming of light;
At eventide I join the birds
In bidding the light farewell.

The plains are decorated with
My beautiful colors, and the air
Is scented with my fragrance.

As I embrace Slumber the eyes of
Night watch over me, and as I
Awaken I stare at the sun, which is
The only eye of the day.

I drink dew for wine, and hearken to
The voices of the birds, and dance
To the rhythmic swaying of the grass.

I am the lover's gift; I am the wedding wreath;
I am the memory of a moment of happiness;
I am the last gift of the living to the dead;
I am a part of joy and a part of sorrow.

But I look up high to see only the light,
And never look down to see my shadow.
This is wisdom which man must learn.

Lowering the bar

I was helping my daughter with some homework the other night. She had been asked to use a spreadsheet program to produce a bar chart. I believe the numbers were densities (g/cm³) and they were something like:

92.5, 91, 93.5, 92

And here's what Excel produced:
The vertical axis starts at 89.5, so the height of each bar represents the density−89.5, which means ... ??

Junk Charts quotes Naomi Robbins, author of Creating More Effective Graphs thus: "all bar charts must include zero". Indeed—otherwise what do the bar heights represent? That Excel's defaults violate this rule is, ahem, unfortunate. (I've tried this using Excel 2000 and Excel on a Mac, but perhaps it's been fixed in newer versions? Maybe?)

Excel can be coerced into starting its vertical axis at 0, but it takes a fair bit of clicking and navigating. The result is:
Relative to a density of zero, there's very little variation. But perhaps this hides the message in these numbers. Doesn't that just bring us back to the first bar chart? Well ... no.


This graph shows the data, with the vertical axis zoomed in to where the action is. Unlike the original bar chart, it doesn't show bars with arbitrary heights.

Again from Junk Charts:

The "start-at-0" rule says that the vertical axis of any graph ought to start at value 0. The rule was mentioned in Huff's classic booklet, "How to Lie with Statistics": as the name implies, the rule is intended to eradicate mischievous graphs that exaggerate small differences by not starting at 0, which is to say, by choosing a misleading scale.

Others, like Tufte and Wainer, have long realized that the start-at-0 rule is not absolute ... My own "anti-rule" stipulates that if all data appearing in a chart are far from 0, then don't start at 0.

If, on the other hand, some of the plotted data are close to 0, then it is essential to start at 0.

This isn't too far from my view, but it doesn't address bar charts, which are a special case because they emphasize the heights of the bars, rather than the position of the tops of bars. Bar charts are only appropriate for variables that are measured on ratio scales. For such variables, there is a non-arbitrary zero, which means that you can calculate a meaningful ratio; e.g. for weight: one thing might weigh twice as much as another. But some variables aren't like that; e.g. IQ: an IQ of zero is meaningless, and so it doesn't make sense to say that someone with an IQ of 100 is twice as intelligent as someone with an IQ of 50. For variables of this kind bar charts make no sense at all.

So, if your variable isn't ratio scaled (in other words, there isn't a meaningful zero), don't use a bar chart. If it is ratio scaled and you decide to use a bar chart, make sure your axis starts at zero.

Derek puts it well in a comment at Pictures of Numbers:

There is a circumstance in which the would-be grapher absolutely must start with zero, and that's when creating a bar graph. If that causes problems, it's time to consider abandoning the bar graph and adopting something which doesn't need a zero on the scale. I've seen bar graphs where the designer recognised the problem with zero, adopted and defended the solutions, but without getting rid of the bar graph format. Those wavy gaps are the least bad of the abortive compromises resorted to by people who won't give up their bars.

In case anyone thinks this really isn't much of an issue, here are some examples I found quite easily:

Food for thought

The global price of food has risen sharply over the last 18 months. This is most acutely the case with cereals. The New York Times reports that wheat has reached its highest price in 28 years. The reasons for this phenomenon seem to be broadly accepted; see for example, Paul Krugman's column or a recent presentation (pdf) by Joachim von Braun of the International Food Policy Research Institute.

Though the relative importance of the reasons is difficult to assess, the list itself seems clear (the price of oil, a growing middle class in China and India with an increasing demand for meat which requires more grain for feed, droughts likely due to climate change, Western government subsidies for biofuels like corn ethanol).

But I wonder if we shouldn't consider a different aspect of this. As the New York Times points out:

Even the poorest fifth of households in the United States spend only 16 percent of their budget on food. In many other countries, it is less of a given. Nigerian families spend 73 percent of their budgets to eat, Vietnamese 65 percent, Indonesians half.

What is wrong with our world that so many people are living so close to the edge? Hmmm ...

Update 14Apr2008: The graph below was produced using Technorati. It shows the number of blog posts (in "any language" on blogs with "some authority") containing "food crisis". Too bad most of us are at least 6 months late.

StatLinks

The Internet makes it possible to link a dispersed community of common interest. Now there are a number of blogs that focus entirely or in part on Statistics, but they seem not to be well connected.

So I've just set up a social bookmarking website just for applied statistics, data analysis, and visualization. It's called StatLinks.

It lists links that users submit, and allows other users to vote on their relevance. Links are listed in order of popularity (or in chronological order, if you prefer).

I encourage people to visit StatLinks, to submit links that are likely to be of interest, and to pass the word! I've put a few links in to get things started. (Hat tip to Slinkset whose technology made it a breeze to set this up.)

Could you keep my place in line?

Line-ups are both eminently civilized and—really annoying! The first in first out (FIFO) principle is inherently egalitarian and respect for it is a sign of social order. But there's something crazy about using our bodies as place keepers in a queue, sometimes for hours on end.

Inevitably, after waiting some time in a lineup, someone will need to step out for a while. Rather than lose one's priority in the sequence, the convention is to ask someone (a complete stranger if need be), "Could you keep my place in line?"

The language here is metaphorical and indirect. The request is not really about keeping a place. It's about promising on the return of the person to vouch to any potential challengers that indeed this particular person was previously in line at this particular point in the sequence.

The fact is, complete strangers generally do agree to "keep your place in line". And that's a further sign of civil behaviour. Maybe line ups aren't so bad after all!

I bet there are lots of good stories about line-ups. I'd love to hear some. Then we could publish a book (I'm trying to think of a queued name for it ...)

P.S. I've tried to give equal time to the different spellings lineup / line-up / line up. I really don't know which is correct. Those who wish to correct me should form an orderly line.

Nature vs. not sure

The perennial nature-vs-nurture debate just won't go away. This is particularly true with regards to gender differences, a subject of broad interest.

I'll acknowledge my biases up front. I have long been skeptical about biological determinism. This is partly because of its historical association with racism, sexism, classism, and the eugenics movement. But it's also because, particularly in recent years, there has been a tendency to overstate the importance of genetics in explaining human behaviour. Part of the explanation for this "genohype" may be the dramatic achievements of the Human Genome Project together with the rise of the biotechnology sector. Just as the success of Darwin's theory of natural selection led to Social Darwinism, today's molecular genetics revolution has put a new wind in the sails of biological determinism.

In the scientific world, the nature-vs-nurture debate is generally accepted to be an ill-posed problem. Because the environment affects the expression of genes, it is not a question of nature versus nurture, but of nature vis-à-vis nurture. Nevertheless, the ways in which and the extent to which nature and nurture influence human behaviour remain controversial. And beliefs about this can have profound consequences.

But one thing's for certain, and that's uncertainty. Despite the way results from studies of gender differences are often portrayed, we're usually left with more questions than answers. Here I want to comment briefly on two considerations that should be borne in mind.

Does the difference matter?

It's common to read reports stating that, for example, "women perform task X better than men". What this really means is "on average women perform task X better than men, and this effect was found to be statistically significant". The magnitude of the effect may be small or large. The degree of overlap between women and men may be small or large. (And of course the study may be flawed.)

To what can the difference be attributed?

Assuming the difference is real and meaningful, we're still left with the question of whether it represents an innate biological difference or an environmental (cultural) difference. For some reason it seems that people quickly jump to the conclusion that gender differences are innate. But in most cases it is extremely difficult to sort this out. Cultural effects can be extremely subtle. As has been pointed out (by ?), the concept of "wet" wouldn't mean much to a fish.

Grist for the mill

Here are three interesting articles that touch on some of these issues. First, a review by Viv Groskop of "The Sexual Paradox: Troubled Boys, Gifted Girls and the Real Difference Between the Sexes" by Susan Pinker. Next, an interview with professor of language and communication Deborah Cameron about her book "The Myth Of Mars And Venus". Finally, a New York Times article by Elizabeth Weil about the movement for single-sex public education based on gender differences.

I've really only scratched the surface of this issue (not to mention related ones), and there's lots of stuff out there (a Google search of "gender differences" gives 2,450,000 results). Comments?

Update 09Apr2008: It seems there's an almost unlimited number of links that could be added. Here's another review of Susan Pinker's book, from the New York Times. Here's an entertaining retort to an argument about gender differences based on evolutionary psychology. And here's a piece that argues: "Nowhere do scientific findings get more mangled than when they’re about the differences between men and women." Finally, here's a conservative view on gender differences.

Update 11Apr2008: Here's a response to some of the arguments about single-sex schooling.