"Hypotheses Are Verified By Testing, Not By Submitting Them To Lay Juries For A Vote"

That quote comes from the conclusion of Judge Cecilia Altonaga's Order granting defendant's motion to exclude plaintiffs' experts in In Re Denture Cream Products Liability Litigation. If you're interested in the problem of causation in toxic tort cases this little gem would make a great primer.

Of particular interest are the following: (a) the court's dissection of the experts' arrangement of bits of unrelated data into what to the casual observer might appear to be a sound deductive argument; (b) the court's discussion of causal inference via induction and its implicit requirement that experts assess ( weigh) and then disclose the strength of their belief in each premise of the argument; and, (c) the court's recognition of the problem of selection bias when paid experts are allowed to opine as to causation using a so-called differential diagnosis or differential etiology approach - they tend, presumably subconsciously, to populate the line-up of suspect causes with the defendant's product and three or four easily ruled-out alternatives.

We especially liked the following about the opinion of plaintiffs' experts: "This theory is not ridiculous, but neither is it necessarily true; it is ripe for testing." That's what we said about Milward. All the plaintiff had was a plausible yet untested (because, said her expert, it was untestable) theory. Traditionally, that hadn't been nearly enough.

There's a clear split between the circuits with most requiring evidence that a theory's prediction has been confirmed at least once before it can go to a jury while a couple of others require only plausibility and an expert willing to say that it's so based on his or her scientific judgment. So it's the empiricists vs. the epistemological anarchists; Popper v. Feyerabend. If the Supremes decide to have a look it'll be a very big deal.

Discretizations

A risk-based tax on rubber duckies?

Tumors are superorganisms.

Kentucky adopts the economic loss rule. (An especially well written opinion btw).

To be injured, you have to be injured. (Wis Ct of Appeals: another well-reasoned opinion worth reading)

Roggli shows that brake repair workers got their meso from commercial amphiboles.

A Stage in the Age of the Phage

Gina Kolata of the NYTimes has an interesting article up today discussing the German E. coli O104:H4 outbreak. It turns out that a combination of two factors, the ability of the bug to produce Shiga toxin and to form a solid and tightly adhering biofilm on the walls of the intestines, is responsible for the severity of the illnesses suffered. It also appears that contrary to original assumptions the bacteria came not from food animals but from people.

How though did E. coli O104:H4 come to acquire the ability to produce Shiga toxin? We know it's produced by E. coli O157:H7 but how did this other bug come to produce a variant of the poison? Enter the phage.

E. coli O104:H4 doesn't have genes that would allow it to make Shiga toxin and guess what? Neither does E. coli O157:H7. Instead, they come from a phage that has infected E coli. and turned it into a deadly pathogen. See "Phage on the Rampage" in Nature News.

So bacteriophages are the villains of the E. coli story, right? Well, yes, and no. It depends on the phage. Clever bioengineers have found another phage that rips E. coli O157H7 apart and they've fed it to cows. The therapy reduces the level of E. coli O157:H7 in cows and thereby reduces the risk of infection to humans. See e.g. "Application of Bacteriophages To  Control Intestinal Escherichia coli O157:H7 Levels in Ruminants" and "Oral and Rectal Administration of Bacteriophages for Control of Escherichia coli O157:H7 in Feedlot Cattle."

Phage therapy isn't just for cows. Though it's been around for decades it was largely ignored in the West and its full potential never unlocked behind the iron curtain. Now, "bacteriophage-based 'probiotic products' may provide a novel, safe and effective approach for favorably manipulating the GI tract's microflora".

A cup of live bacteria chased with a spoonful of phages - together sent into your gut daily to wage war against our ancient enemies. What a world. And because it's so far beyond the future world we imagined we can be certain that at least some of the adventures on which we'll embark will end badly. And that means mass torts will be around for the biological revolution just as it was for the industrial version.

The Texas Supreme Court Issues an Unsettling Opinion on Causation

BIC Pen Corp. v. Carter has been decided, again, and seemingly for the last time. The court previously disposed of the design defect claims and this time the tragic case of a little girl severely burned as a consequence of her five-year-old brother playing with a lighter was before the court on the issues of manufacturing defect and causation.

Given that BIC's own tests of the lighter involved in the accident showed that a flame was produced more readily (because less force was required) than designed the court steamrolled over BIC's manufacturing defect arguments. It gave especially short shrift to the manufacturing variance argument (which actually has a lot of merit). Thus, by the time the opinion gets to causation, a defect for which liability may be imposed having just been found, to the reader things look pretty grim for BIC.

The court focused immediately on the issue that decides causation. Since lighters are designed to be child-resistant and not child-proof (as otherwise lots of adults could not operate them) how do we know that Carter's brother wouldn't have been able to light it anyway? Which is to ask how do we know that but for the defect Carter's brother would not have started the fire? Clearly Carter has to produce some evidence that her brother was enabled by the defect since even if a lighter meets the CPSC standard for lighters it may still be usable by 15% of children his age.

First the court looks at evidence that the brother was developing more slowly than a typical boy his age. The idea is that if the boy was cognitively more like a four-year-old than like a five-year-old then it's more likely that he was indeed enabled by the defect. The court quite rightly decided that it was an apples to oranges assertion because the defect was in a feature meant to physically deter children whereas there was no defect found in the mechanism meant to confound them. Next the court turned to Carter's contention that she could prove her brother was enabled by the defect using the reasoning of Havner.

Carter points to data indicating that low-force-to-operate levels in lighters such as the one in question quadruple the likelihood of a child being able to produce a flame. If Havner requires a doubling of the risk isn't a quadrupling more than enough? Before we get to how the court decided this issue let's run the numbers. As best we can tell there is at least one good test showing that the number of children able to active the lighter goes from 4% to 16% when the physical deterrent to ignition (force) is reduced. Now, assuming that the lighter in question produced a reduction in force necessary to produce a flame similar to the one used in the test then we can calculate how likely it was that Carter's brother was enabled by the defect. Using Bayes' Rule, the likelihoods of ignition for as-designed lighters and reduced force lighters and our knowledge that the lighter in question was in fact defective we can calculated that the likelihood that Carter's brother would not have been able to start the fire (i.e. was enabled by the defect) but for the defect is 75% - a result easily clearing the "more likely than not" hurdle.

Now, the court could have decided that the quadrupling of risk of ignition involved a different level of force (which, in fact, it did) and that plaintiff had zip, zero, nada evidence that the reduction in force at issue (a very tiny one) has ever been shown to double, much less quadruple, risk (which, apparently, it has not). That would have preserved and extended to manufacturing defect cases the rational decision-making approach to uncertain cases established by the court in Havner. Instead, the court decided that probabilistic reasoning can't be used in manufacturing defect cases and gave an extraordinarily weak rationale for doing so.

The court held that "[t]he nature of the injury-causing activities and testing that would have to be done to show causation in this case are not similar to, nor do they pose the practical difficulties posed by, those we considered in Havner. In this case, testing of J-26 lighters posed no unreasonable risk of injury to the test subjects as would have been the case if testing of the drug on humans had been performed under the facts of Havner ... In such instances, tests are done with surrogate lighters that do not pose a risk of harm to the participating children. And testing was also performed on the Subject Lighter itself that posed no risk of injury. Thus we decline to adopt a Havner-type analysis as to causation in this case where manufacturing defects are the basis for the liability claim."

So, because the test subjects tested lighters that didn't contain butane and because the lighter in question posed no risk of burning children when it was tested in a lab post accident, modern techniques for inferring causation aren't appropriate? With all due deference that makes no sense whatsoever.

Maybe the court was worried about permitting Havner-esque analysis in manufacturing defect cases because eventually it would be deployed in a case where the allegedly defective product had been lost or destroyed. If so, a defendant's product could indeed be found to have been more likely than not the cause of the accident even though the product was lost or destroyed. But for that to happen one of two things would have to hold true. Either the defect was responsible for a huge percentage of all such accidents or a huge percentage of the product had been manufactured defectively. In this case, for example, had the lighter been destroyed in the fire plaintiff could not show "more likely than not" (even assuming a quadrupling of the risk) unless she could also show that at least two-thirds of all lighters had the reduced-force defect. Either way, imposing liability when a defect is almost always the cause of an accident or when almost all of the product involved has been defectively manufactured hardly seems an injustice.

Case by case for more than a decade the Texas Supreme Court has worked to produce a coherent and just approach to causation by demanding sound science and utilizing modern decision theory approaches when reasoning out the cases before it. Hopefully, given our fondness for Havner, the true meaning of BIC Pen Corp. v. Carter is exceptio probat regulam in casibus non exceptis.

The Attempted "Reshapement" of Toxic Torts

Building up to the publication of the Restatement (Third) of Torts and now reaching what must surely be a crescendo has come one law review article after another assailing various courts' (re)adoption of the Enlightenment's view of causation and their (re)embrace of empiricism. Last Friday for example we posted a link to a recent paper making the case that loose causation standards (as opposed to those of "classical liberalism") in toxic tort cases are vital to the consolidation and empowerment of "the administrative state". And a couple of days before that we wrote about another new article that attempts to provide intellectual support for the proposition that the consequence of courts' application of strict causation standards has been to tip the scales in favor of defendants. Today we'll address an assertion from the second article.

On page 107 author Gold makes the following claim: "To the extent courts treat general and specific causation as separate elements requiring distinct proof, plaintiffs who already confront scientific uncertainty may be required to jump two hurdles instead of one - increasing the likelihood of false negative adjudications on causation." What he's done is to confuse what happens when we estimate the probability of the conjunction of two events (here: e.g. the likelihood that tetra-methyl death (TMD) can cause prostate cancer and the likelihood that plaintiff's prostate cancer was actually caused by TMD) with the manner in which false positives and negatives are identified and the manner in which the odds of being false negative or false positive are estimated. A simple illustration will hopefully suffice.

On chromosome 19, carried by both men and women, is a gene, KLK3, a variant of which is highly correlated with prostate cancer. There's a test for prostate cancer that looks for the KLK3 variant. Since both men and women carry the gene what happens to the number of false negatives (the KLK3 test shows they don't have the variant but later they're found to have prostate cancer after all) and false positives (the test says they have it but they really don't) if a general causation "hurdle" like "can women even get prostate cancer?" is placed before the KLK3 test? The number of false negatives is unchanged (good) and the number of false positives is cut in half (great).

What we suspect Gold is trying to complain about is the following: If we're 51% sure that TMD is a cause of toe cancer and 51% sure that of the possible causes of plaintiff's toe cancer TMD was actually the cause of it then across the set of toe cancer plaintiffs there will be some who recover nothing because of the extreme uncertainty in the science. But that's really just proof that the law is far too lenient towards plaintiffs in toxic tort cases.

What are the odds that our hypothetical toe cancer plaintiff actually got his toe cancer from TMD? Only 26.01% (51% x 51%) - hardly "more likely than not". Yet every court in the country will let a toxic tort plaintiff stack uncertainty upon uncertainty, "more likely than not" upon "more likely than not" to get to a cumulative "more likely than not" in spite of the fact that mathematically that ain't how it works. Furthermore, given the fact that courts will allow plaintiffs to establish both general and specific causation with a single study demonstrating a relative risk (RR) of 2.0 and given the fact that most published research findings with low (less than 4-ish) RRs are false anyway the odds that our toe cancer plaintiff waving his toe cancer - TMD peer reviewed paper actually got his cancer from TMD is no more than 13% (51% x 51% x 51%) and likely much lower - yet he'll get to a jury, meaning he'll be offered a settlement, in every courthouse in the land.

At the end of the day the "Reshapement" of toxic torts won't increase the odds of truly wronged plaintiffs being compensated but it will, where adopted, swamp unfavored companies with meritless claims - perhaps that's the whole point of it.

 

 

Discretizations

NTP Adds Formaldehyde to "Known", Glass Wool FIbers and Styrene to "Reasonably Anticipated To Be" Lists of Human Carcinogens

Formaldehyde has been known to be a cause of nasopharnygeal cancer for a long time but the NTP's determination that it likely causes leukemia and other lymphohematopoetic cancers is a big deal. The inclusion of styrene on the list of things "reasonably anticipated to be a human carcinogen"is the real shocker though. Back in the late 80s when the butadiene litigation was beginning to unfold there was considerable worry about whether the other big component of styrene-butadiene rubber might be a carcinogen. Numerous studies settled the question and the litigation never went anywhere (well, they sued the butadiene people instead of the styrene people). Expect styrene litigation.

Finally, the glass fiber determination brings with it a fair share of irony. For years asbestos plaintiff lawyers claimed that glass wool was a safe, non-carcinogenic substitute fiber (and I'd bet it is, actually). For more see: "12th Report on Carcinogens" or the report itself in .pdf.

Discretizations

The "Reshapement" (Third) of Toxic Torts?

Want some more evidence that at least with regard to toxic tort cases the Restatement (Third) of Torts is nothing of the sort but rather an effort by "the academy" to impose its vision of what the law ought to be? Read "The 'Reshapement' of the False Negative Asymmetry in Toxic Tort Causation".

The central premise of the paper is that for a variety of reasons the law has decided to err on the side of letting victims of toxic chemicals go uncompensated (a sort of "false negative") rather than letting errors of judgment fall with equal frequency on the wrongly accused (the false positives). However, unlike say the science surrounding breast cancer and mammography the author presents no data to demonstrate that there are more victims on the Plaintiff side of the ledger than on the Defendant side. Instead, he argues in essence that because science (as opposed, somehow, to plaintiffs' retained scientist experts) plays it safe and errs on the side of false negatives. By adopting such methods the courts then necessarily put a thumb on the "D" scale.

Of course the real reason epidemiologists, toxicologists and the like have learned to go slow in the face of uncertainty is that the proportion of false positives to false negatives was enormous throughout the 70s, 80s and 90s. Small relative risks and the peculiar metabolism of mice launched false health scare after false health scare. Contrary to what the author suggests the vast majority of positive findings have turned out to have been false - that's why coffee alone has been falsely implicated in more cancers over the last forty years than has human carcinogenicity been confirmed in all chemicals combined.

There's lots to dissect in the paper and we'll be doing so in coming days. One topic we'll hit is the effort to sneak the so-called precautionary principle into the law via Comment "c" of Section 28, Liability for Physical and Emotional Harm. See page 1572 for the author's approving nod to the effort which had previously been denied by the comment's reporters.

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