In the public imagination, natural scientists have figured out a lot more reliable and non-obvious things about the world, compared to what non-experts would guess, than social scientists have. The insights of quantum mechanics and relativity are not things that most of us can even think sensibly about without quite a bit of background study. Social scientists, meanwhile, talk about things most people are relatively familiar with.

Hey, economists can talk obscure technical jargon just as easily as physicists. We don’t actually do that so much in public, because the public respects us less. Talking more technically wouldn’t make the public respect us more.

On the very basics of their fields (the Big Bang model, electromagnetism, natural selection), almost all natural scientists are in agreement. Social scientists seem to have trouble agreeing on the very foundations of their fields. If we cut taxes, will revenue go up or down? Does the death penalty deter crime or not? For many people, a lack of consensus gives them license to trust their own judgment as much as that of the experts.

Revenue if tax cut and crime if death penalty aren’t remotely near the foundations of economics. We can’t talk about economic foundations in public without using obscure technical concepts the public won’t tolerate. Physicists are more allowed to talk their foundations in public, as they are allowed more tech talk. (I’ll consider consensus issues below.)

The social sciences deal with fantastically more complicated subjects, about which it’s very naturally more difficult to make definitive statements, especially statements that represent counterintuitive discoveries. The esoteric knowledge that social scientists undoubtedly possess, therefore, doesn’t translate directly into actionable understanding of the world, in the same way that physicists are able to help get a spacecraft to the moon.

There is a final point that is much trickier: political inclinations and other non-epistemic factors color our social-scientific judgments, for experts as well as for novices. … When deciding where to place that trust, we rely on a number of factors, mostly involving the track record of the group to which the purported expert belongs, if not the individual experts themselves. So my advice to economists who want more respect from the outside world would be: make it much more clear to the non-expert public that you have a reliable, agreed-upon set of non-obvious discoveries that your field has made about the world. People have tried to lay out such discoveries, of course — but upon closer inspection they don’t quite measure up to Newton’s Laws in terms of reliability and usefulness.

The public is taught to credit physicists for all those physical things around them they enjoy, like cars, planes, phones, and skyscrapers. The public is not taught to credit economists for all those great economic institutions around them like markets, firms, cities, and industries. So naturally physicists are seen as contributing more. But is this fair?

Yes, economists were only a supporting influence in creating all those great economic institutions, unless we want to define all businessmen as economists. But similarly, physicists were only a supporting influence in creating all those great physical devices, unless we want to define all engineers as physicists. There were useful steam engines long before thermodynamics helped explain them, and it took far more than basic physics to get men to the moon, just as it took far more than basic economics to create modern industries. It is actually quite hard to say which discipline has been more useful overall to the world.

They key difference, I think, is that more interested parties see themselves as losing if the public listens to economists, and these parties therefore dispute economists in public. Such interested parties also influence individual economists, and so weaken within-economics consensus. In contrast, few care enough about what physicists say to dispute them in public.

The fact that economists are more disputed in public than physicists seem plenty sufficient to explain the differing public treatment of the two fields. Even if physicists did have a more “reliable, agreed-upon set of non-obvious discoveries,” that couldn’t explain the differing public treatment of the two fields for the simple reason that the vast majority of the public has no idea about such things. They don’t know about physical or economic discoveries, nor about how reliable or useful such things are. What the public mainly knows is that when physicists talk few disagree, but when economists talk lots of folks disagree, and each ordinary Joe is himself often tempted to disagree.

Now the fact that economists are more disputed does in fact give the public more reason to doubt what economists say. But this only justifies increased uncertainty, not swapping expert opinion for their own personal reasoning. The desire to believe that what is in your interest is also in the general interest can on average distort individual reasoning just as much as it can expert reasoning, if not more so. In both fields it is better to believe nothing, or believe the experts.

If you want to learn to do science, with all the thrills of actually discovering anything, you are probably best to pick an area where people don’t already know all of the cheap answers … Does decreasing the length of my skirt increase the propensity of the cool students to talk to me? Does learning the piano as a child really make people happier later in life? Does Father Christmas exist? Do the other children hate me or are they just indifferent? What factors best cause my brothers to leave me alone? How much do my grades change if I do half an hour more or less homework each night? Does eating sugar all evening really keep me awake? How often will I really be approached by potential kidnappers if I hang out at the mall by myself after school? …

Most children and teenagers disagree with their parents, teachers and other adults on a large number of issues. Investigating those issues scientifically might have the added benefit of getting students in the habit of keeping their opinions related to reality. (more)

Given the typical expression on the typical student’s face, it is amazing that schools present themselves as sanctuaries of personal fulfillment, and sacred founts of creativity and innovation. School advocates imply: “All the great artists, scientists, etc. did well at school, and without school they’d be so much less.” But in fact schools arose with industry to get folks to accept the regimentation and ranking of the industrial workplace, and to curb natural human creativity, exploration, and challenging of authority. As Katja’s proposal’s illustrates, schools could in fact teach folks how to question common beliefs “scientifically,” if in fact authorities wanted common folks doing that sort of thing.  As I’ve written:

School is mostly not about the material taught in classes. I’m less sure to what extent it is about learning-to-learn, coming-to-obey, bonding with other kids, and signaling these features as well as intelligence and conscientiousness. I’m pretty sure signaling of various sorts is at least 30% of the average private value of school, and it could go as high as 80%. … The best evidence I’ve seen that school adds great value is the stories I’ve heard about how difficult are employees who grew up in “primitive” cultures without familiar schools. Apparently, it is not so much that such folks don’t know enough to be useful, but that they refuse to accept being told what to do, and object to being publicly ranked relative to co-workers. (more; see also more)

Spending on science is one of the best ways to generate jobs and economic growth, say research advocates. But … the evidence behind such claims is patchy.

The number one current rationale for extra research investment is that it will generate badly needed economic growth. … Heeding such arguments, governments in Germany, Sweden, Canada and Australia, as well as the United States, have increased research spending as part of stimulus packages …  Beneath the rhetoric, however, there is considerable unease that the economic benefits of science spending are being oversold. … The problem, economists say, is that the numbers attached to widely quoted economic benefits of research have been extrapolated from a small number of studies, many of which were undertaken with the explicit aim of building support for research investment, rather than being objective assessments. … “Too much of what has been done, has been done as a process of advocacy.” …

In one of the bedrock papers in this field, Edwin Mansfield, the late University of Pennsylvania economist, estimated that academic research delivered an annual rate of return of 28% (E. Mansfield Research Policy 20, 1–12; 1991). The figure has been widely quoted ever since. But Mansfield reached this estimate by interviewing chief executives, asking them what proportion of their companies’ innovation was derived from university research and, in effect, demanding that they come up with a number. “He was asking an impossible question.” …

Measuring the ROI from research has proved tough, and has produced a wide range of values (see table). Some … [ask] what contribution did a dozen neuroscience grants received by the University of Cambridge in 1972 eventually make to drug development? Such efforts are complicated, however, by the difficulties of attributing credit for any given drug to the numerous research teams involved over time. … “It is fair to say that this is an analytical dead end.” …

This [PR] influence derives in part from the activities of US medical research lobbyists. An example is the 2000 report Exceptional Returns: The Economic Value of America’s Investment in Medical Research by … Mary Woodard Lasker Charitable Trust that advocated biomedical research spending. … The document estimated that the steep decline in cardiovascular deaths in the United States between 1970 and 1990 has an economic value of $1.5 trillion annually, and deduced that one-third of this — $500 billion a year — could be attributed to medical research that led to new procedures and drugs. … Robert Topel, … whose work was cited in the report, distances himself from some of its claims. “Probably only a little of the fall in the cardiovascular death rate has to do with surgery and beta-blockers,” he says. …

Research agencies have no interest in assessing the costs of research fairly, says Barry Bozeman, a science-policy specialist. … “Honest clients are in short supply” for research in this field, he says. “Most of them think they already have the answers, and want someone to find the numbers to prove them right.”

Paul Davies, chair of the group that decides what SETI scientists will do if evidence of aliens is ever found, thinks … until scientists can say something to the public with great (~99%) confidence, they should say nothing. … Most early low-probability signs … being false alarms is “damaging to the credibility of science.”  So until scientists can confidently say that an asteroid will hit us or that we see aliens, they should just whisper to each other. … One might justify this confidence-or-silence policy by arguing … reporters are biased to present low probability news as if it were high probability.

Today’s Post:

NASA … reopened a 14-year-old controversy, … reaffirming and offering support for its widely challenged assertion that a 4-billion-year-old meteorite that landed thousands of years ago on Antarctica shows evidence of microscopic life on Mars. … Fourteen years of relentless criticism have turned many scientists against the McKay results, and the Mars meteorite “discovery” has remained an unresolved and somewhat awkward issue.  This has continued even though the team’s central finding — that Mars once had living creatures — has gained broad acceptance. …

Critics had said that the magnetites could have just as easily existed without bacteria or biology — that they sometimes form as a result of the shock and searing heat that could come, for instance, from an asteroid strike. But … [a] recent paper … reported that the purity of the magnetites made that explanation impossible. … “All the criticisms of our original paper got widely distributed, but when we did the work to prove the critics were wrong, it hardly made a ripple. … We’re now in a position to say we’ve knocked down all the criticisms — and our biological explanation is the one left standing.” …

At the conference, a leading cautionary voice in astrobiology proposed that a special protocol be established to oversee release of any journal articles making dramatic extraterrestrial claims. Andrew Steele … compared the absence of astrobiology review with the formal procedures set up by scientists involved with the search for extraterrestrial life, or SETI.  He said that SETI leaders understood the societal sensitivity of their work and that it was time for researchers in astrobiology “grow up and do the same.” (more)

Yet another voice for muzzling!  It seems clear to me that scientists do not usually insist on such high standards of confidence for publication.  Most Research Findings Are False seems pretty clear evidence, as does the high rate of celebrated new medical treatments that are later repudiated, and the very low marginal health-effectiveness of medicine.  I suspect I see similarly low standards for publications that are pro-global warming, or that warn of low science funding or manpower.  If the standard of evidence for publication varies with the topic, we can’t explain it via a generic tendency for reporters to exaggerate findings.  So what explains this variation?

Here I’ll channel Tyler Cowen, and suggest this is mostly about how real events echoing stories we tell change which intellectuals get more status.  Think of all the movies you’ve ever seen of an outsider intellectual unfairly rejected by establishment scientists.  Evidence of aliens, or a Really Big Disaster are prototypical.  Well establishment scientists see those movies too, and they don’t want real stories like them to appear in the media. They correctly perceive, for example, that a story confirming aliens would raise the status of UFO nuts, relative to establishment academics.  Similarly, news about a really big disaster would raise the status of “the sky is falling” outsiders.

On the other hand, establishment academics correctly perceive their status would be raised, relative to outsiders, by more stories of promising new medical treatments, of the seriousness of global warming, of the need for more science funding, or that a new result “might lead to a new theory of everything.” Even if such stories turn out later to be wrong.  Why?  Because we hear many similar stories about heroic scientists discovering treatments, or warning of enviro disaster, and few stories about such scientists being later wrong.

I see two effects:

1. There are some long standing disagreements between insider and outsider intellectuals in our society, and any news that confirms outsider claims raises outsider status.
2. News about a real event about you that matches a commonly-told story in which you’d be a hero, raises your status.   If that news is later reversed, that won’t reverse your status, if there aren’t commonly told stories about you being a villain in a news reversal story.

Paul Davies, chair of the group that decides what SETI scientists will do if evidence of aliens is ever found, thinks similarly about science news: until scientists can say something to the public with great (~99%) confidence, they should say nothing.  (Quotes below.)  You see, frequent public updates on science issues of great popular interest, like evidence of aliens or asteroids headed toward Earth, would result in reporters bothering scientists at work with “mayhem”, disrupting their “lines of communication,” and disturbing their “dispassionate analysis.”  The fact that most early low-probability signs would end up being false alarms is “damaging to the credibility of science.”  So until scientists can confidently say that an asteroid will hit us or that we see aliens, they should just whisper to each other.

In the extreme case of receiving an actual alien message directed at us, Davies prefers scientists to kept quiet for the many years it would likely take to decode it fully.  And he prefers aliens to not send us any useful tech info, as then we would fight over who could decode it first.  How disruptive!

One might justify this confidence-or-silence policy by arguing either that non-scientists are biased to overreact to low confidence news, or that reporters are biased to present low probability news as if it were high probability, and non-scientists gullibly believe them.  I have not seen any systematic evidence presented in support of these claims, however.

Within academia, the bias against non-top articles seems like signaling.  Since folks confident they are great would not admit they’d ever done work that could not meet the highest standards, medium journal publications reveal a lack of confidence.  Similarly, I suspect signaling is behind the confidence-or-silence policy.  Since it is harder to credibly say something with great confidence than with low confidence, saying something with low confidence sends a bad signal about your abilities.  Keeping info secret is also a status move; info gives control and control marks status.

Quotes from Eerie Silence:

The fact that it may take days to be sure that a [SETI] signal is not manmade raises a very serious problem for managing the post-detection agenda. … Any hint of a positive result from a SETI project could immediately trigger media frenzy, and events might soon spiral out of control. … In the case of the SOHO satellite detection, the press got hold of the story even before the identification was made.  Fortunately the reporter concerned acted responsibly and waited for more data before rushing into print.  But not all members of the media can be relied upon to be so restrained. …

Because SETI astronomers are professional scientists, rigorous checking is an essential part of their training, and they want to be sure of their ground before making a definitive statement. History has shown that when scientists run to the press with sensational claims that haven’t been properly checked, the outcome is very damaging to the credibility of science itself, not to mention the reputations of the scientists involved.  A salutary lesson in how not to handle the media comes from the now largely discredited claim for cold nuclear fusion … They held a hasty press conference, and the media understandably had a field day. … It took many months for laboratories around the world to test the claim, and find it wanting. …

The lesson from that debacle is that it is wise to exercise restraint when dealing with the media about discoveries that carry sweeping implications for society. In the case of SETI, … once word got out, mayhem could ensue.  The astronomers might show up for work only to find their observatory besieged by journalists, … hardly an environment conducive to dispassionate analysis.  Even normal modes of communication are likely to be disrupted as lines become jammed by callers eager to check the rumors. …

It is in the nature of this type of investigation that false alarms greatly outnumber the real thing, so the above scenario might be played out many times, with the hullabaloo eventually subsiding as the story evaporates. A close analogy is the all too frequent announcement that civilization is menaced by an oncoming asteroid or comet. … When a new asteroid or comet seems to be moving on an Earth-crossing trajectory, … carefully checking takes time.  In the early days following the discovery, the projected orbits are uncertain because of normal measurement errors.  After the object has been followed for several days or weeks, the errors shrink enough that the astronomers can then work out whether it will or won’t hit Earth.  The most sensible strategy is to wait until the orbit has been properly determined, and only then, if there is still a clear and present danger, ‘wake the President’.  But … more often than not, the press get wind that a new object has been found that might strike our planet on the next orbital pass. It makes a wonderful scare story: ‘Killer asteroid may wipe out life as we know it!’  Headlines like that attract a lot of readers. … The known uncertainty in the measurements lets astronomers work out the probability of a collision – typically it is about one in 10,00 when the object is first identified. …

I personally believe the public does have a right to know, even if the news is bad – as soon as the situation is properly understood. I have yet to meet with a SETI scientist who doesn’t agree with this basic principle. There is no ‘code of secrecy’ in SETI. … Suppose the … discovery holds up at, say 99 per cent confidence level. …  If an astronomer were to spot something weird, which on closer inspection bore all the hallmarks of artificiality, then I believe it should be announced just like any other major astronomical discovery. … If an alien civilization were to send us a customized message, … I personally feel that the implications of simply  receiving such a message would be so startling and so disruptive that, all though eventual disclosure is essential, every effort should be made to delay a public announcement until a thorough evaluation of the content had been conducted, and the full consequences of  releasing the news carefully assessed in light of the Taskgroup’s recommendations. …

Information about the astronomical coordinates of the transmitter should be restricted to the astronomers involved … Even governments … no doubt would also want to take charge.  In my view, however, the less government involvement at the evaluation stage, the better. … Decoding it could take a very long time, perhaps involving years of meticulous work before we had any idea of what we were dealing with. … Most worring of all would be [a message] that merely handed us on a plate a revolutionary item of technology, e.g. a new source of energy, or a technique for engineering designier life forms reliably.  The problem here is that the gorup that possessed the knowledge first would be in a position of incomparable power. … Outright warfare might follow the scamble to grab the information. One can only hope that the aliens would recongnize the dangers and refrain from handing out scientific secretes like sweets.  [pp172-184]

[Science journalism] converts original scientific findings, via a production line of embargoed press releases from journals and universities, into a steady stream of largely uncritical stories. … In stark contrast to proper investigations of issues such as public corruption, corporate maleficence or industrial health and safety — essentially silly stories about science continue to fill newspapers and news broadcasts.  Some science reporters are uneasy about this situation, but most accept it. … Most [scientists] seem to be largely content with a system that disguises the very human process of scientific discovery as a seamless stream of ingenious and barely disputed ‘breakthroughs’. Like other elites, researchers feel no great yearning to be held to account by the press. ….

There is a need for dedicated newspaper sections, radio and TV programmes, more akin to existing sports coverage, that can provide detailed, critical assessment of the scientific enterprise for people who really like science.  Reporters and editors could then engage with sets of findings and associated issues of real societal importance in the news pages, asking the hard questions about money, influence and human frailty that much of today’s science journalism sadly ignores. …

The machine … serves the short-term interests of its participants. … Researchers, universities and funding agencies get clips that show that their work has had ‘impact’. And readers get snippets, such as how red or white wine makes you live longer or less long, to chat about at the water-cooler. … Science is being misrepresented as a cacophony of sometimes divergent but nonetheless definitive ‘findings’, each warmly accepted by colleagues, on the record, as deeply significant. The public learns nothing about the actual cut and thrust of the scientific process.

Yes, science reporting is less critical than political, business, or sports reporting.  Since the media is very competitive, readers/viewers must prefer it that way.  But why?

First, we are far more suspicious of bids for dominance-status than for prestige-status.  We see politicians and businesses as threatening to dominate us and so we are eager to watch out for illicit power grabs.  In contrast, we see science, arts, literature, etc. as only awarding prestige, not power, and we are less worried about illicit prestige grabs.  We mainly care about prestigious stuff as ways to see who is more impressive, and a tricky “illicit” prestige grab is itself pretty impressive, so little harm done.

Also, we like some critical reporting on sports, music, and literature because we are expected to choose sides in these areas as part of our identity.  We are supposed to have our favorite band, team, or author, and so we appreciate news rehearsing arguments we might offer for or against such things

But we are not supposed to have favorite positions on science disputes.  Science is more like our communal religion, something that distinguishes us advanced insiders from those ignorant outsiders, and we are eager to signal being part of us and not them.  It is like how, aside from worrying about power-grabs by our military leaders, we are not each supposed to have a different favorite war strategy for our troops – that would be divisive and we prefer to show that we are united against them.

Sciences of politics or business are of course the obvious exception, as we suspect illicit power in politics or business might be supported by illicit scientists.  So we do see critical reporting in these sort of sciences.

Of the many ways of gathering advice from experts, the Cooke method is, in my view, the most effective when data are sparse, unreliable or unobtainable. … Take as an example an elicitation I conducted in 2003, to estimate the strength of the thousands of small, old earth dams in the United Kingdom. Acting as facilitator, I first organized a discussion between a group of selected experts. … The experts were then asked individually to give their own opinion of the time-to-failure in a specific type of dam, once such leakage starts. They answered with both a best estimate and a ‘credible interval’, for which they thought there was only a 10% chance that the true answer was higher or lower.

I also asked each expert a set of eleven ‘seed questions’, for which answers are known, so that their proficiency could be calibrated. One seed question, for example, asked about the observed time-to-failure of the Teton Dam in Idaho in June 1976. Again the specialists answered with a best estimate and a credible interval. Their performance on these seed questions was used to ‘weight’ their opinion, and these weighted opinions were pooled to provide a ‘rational consensus’. For the UK dams, the performance-weighted solution indicated a best estimate of time-to-failure of 1,665 hours (70 days) — much higher than if all of the answers were pooled with equal weights (6.5 days).

So what evidence shows this is “most effective”?  First, other methods aren’t perfect:

The traditional committee still rules in many areas … Committees traditionally give all experts equal weight (one person, one vote). This assumes that experts are equally informed, equally proficient and free of bias. These assumptions are generally not justified.  … The Delphi method … involves getting ‘position statements’ from individual experts, circulating these, and allowing the experts to adjust their own opinions over multiple rounds. … What often happens is that participants revise their views in the direction of the supposed ‘leading’ experts, rather than in the direction of the strongest arguments. … Another, more recent elicitation method … involves asking each participating expert to predict the range of uncertainty estimates of any and every person in the field. This creates a huge spread of overall uncertainty, and sometimes physically implausible results: it once implied higher earthquake risk in Switzerland than in California.

Second, more folks are using and liking it:

We were able to provide useful guidance to the authorities, such as the percentage chance of a violent explosion, as quickly as within an hour or two. … More than 14 years on, volcano management in Montserrat stands as the longest-running application of the Cooke method. … The Cooke approach is starting to take root in similar problem areas, including climate-change impacts on fisheries, invasive-species threats and medical risks. … Participants found the elicitation “extremely useful”, and suggested that it would be helpful in assessing other public-health issues.

And, that’s it.  No lab or field trials comparing this method to others are offered, nor can I find them elsewhere, nor are they mentioned under future “research questions.”  Strangely, it is as if scientist Aspinall and his top science journal editor never considered scientific trials!

People complain that we don’t have enough kinds trials comparing prediction markets to other methods – not enough different topics, methods, timescales, etc. And they aren’t always dramatically better.  But, hey, at least we have some trials.  Why doesn’t Aspinall even list prediction markets among competing methods?

My guess: scientists must manage a delicate balance.  Their customers mainly want to affiliate with prestigious academics, and so need official estimates to come attached to the names and affiliations of such academics.  They’d be fine with a simple vote of a committee of prestigious academics.  But the scientists want to estimate in more “scientific” ways, with numbers, procedures, etc.  Weighting votes by test scores fits that bill.

Prediction market estimates might be more accurate, but they less clearly come attached to prestigious academics, so scientist customers won’t like them.  Each scientist also prefers when possible to affiliate with other prestigious academics, and so also prefers to join prestigious committees, however weighed, than to trade in prediction markets.

Alas, only strong clear evidence that prediction markets are more accurate on such topics is likely to embarrass scientists and their customers enough to get them to prefer markets to committees.  And neither are eager to pay for trials that might produce such evidence.

Although the researchers were mostly using established techniques, more than 50 percent of their data was unexpected. (In some labs, the figure exceeded 75 percent.) … “The results kept contradicting their theories. It wasn’t uncommon for someone to spend a month on a project and then just discard all their data because the data didn’t make sense.” …

There were models that didn’t work and data that couldn’t be replicated and simple studies riddled with anomalies. “These weren’t sloppy people,” Dunbar says. “They were working in some of the finest labs in the world. But experiments rarely tell us what we think they’re going to tell us. That’s the dirty secret of science.” …

Most such anomalies are just ignored:

The vast majority of people in the lab followed the same basic strategy. First, they would blame the method. The surprising finding was classified as a mere mistake; perhaps a machine malfunctioned or an enzyme had gone stale. … The experiment would then be carefully repeated. Sometimes, the weird blip would disappear, in which case the problem was solved. But the weirdness usually remained, an anomaly that wouldn’t go away.  …

Even after scientists had generated their “error” multiple times — it was a consistent inconsistency — they might fail to follow it up. “Given the amount of unexpected data in science, it’s just not feasible to pursue everything.” …

Marginalized folks contribute more to innovation:

Thorstein Veblen was commissioned … to write an essay on how Jewish “intellectual productivity” would be changed if Jews were given a homeland. … [he] argued instead that the scientific achievements of Jews — at the time, Albert Einstein was about to win the Nobel Prize and Sigmund Freud was a best-selling author — were due largely to their marginal status.  … They were able to question everything, even the most cherished of assumptions. …

Diversity induces far view talk, which finds creative answers:

The diverse lab, in contrast, mulled the problem at a group meeting. None of the scientists were protein experts, so they began a wide-ranging discussion of possible solutions. …. “After another 10 minutes of talking, the protein problem was solved.” .. The intellectual mix generated a distinct type of interaction in which the scientists were forced to rely on metaphors and analogies to express themselves. … These abstractions proved essential for problem-solving, as they encouraged the scientists to reconsider their assumptions. Having to explain the problem to someone else forced them to think, if only for a moment, like an intellectual on the margins, filled with self-skepticism.

Thorstein Veblen is under-appreciated, as is how weak are our theories.  How much innovation do we lose because Jews are no longer on the margin?  Hat tip to R0bert Koslover.

[Johnstone & Finch's] Scientific Scandal of Antismoking … makes the case that smoking is not bad for your health. … [It has] the superficial appearance of referencing scientific studies and claiming the the mainstream misrepresents the results.

Yes, they are superficially credible.  Their New Scientist letter:

WHO … claims … “an epidemic of chronic illnesses … could be prevented through simple changes in diet, by being more active and by not smoking.” … There have been a number of such studies, with various combinations of these three lifestyle factors, including the WHO collaborative trial (60,881 subjects, 6 years), the Goteborg trial (30,022 subjects, 11.8 years) and the Multiple Risk Factor Intervention trial (12,866 subjects, 7 years).  These and another eight trials were conducted over three decades, one of the most expensive and sustained series of biological experiments in the history of medical science. … None showed any improvement in life expectancy and two showed a significant reduction in life expectancy in the test group.

So I dug further; bottom line:  Johnstone & Finch are right.  We usually see strong correlations between death and smoking, and we see those same correlations within each random arm (i.e., group) of a randomized trial.  Nevertheless, we see no significant net death differences between control arms and arms induced to smoke less.

So we don’t have clear evidence that smoking kills on net; it could be that most or all of the death-smoking correlation is due to selection effects, and not smoking causing death.  Experts say there is a substantial causal component, and for now I’m accepting that claim, but this lack of clear evidence is suspicious, and disturbing.  Now for some details.

First I know of only one randomized trial directly and only on smoking.  Of 1400 men, a random half were advised to stop smoking, and stop they did:

A randomised controlled trial of anti-smoking advice in 1445 male smokers, aged 40-59, at high risk of cardiorespiratory disease. After one year reported cigarette consumption in the intervention group (714 men) was one-quarter that of the “normal care” group (731 men); over 10 years the net reported reduction averaged 53%. The intervention group experienced less nasal obstruction, cough, dyspnoea, and loss of ventilatory function.

The results:

During the next 20 years there were 620 deaths (231 from coronary heart disease), 96 cases of lung cancer, and 159 other cancers. Comparing the intervention with the normal care group, total mortality was 7% lower, fatal coronary heart disease was 13% lower, and lung cancer (deaths+registrations) was 11% lower.

However, these differences are clearly not statistically significant.  (The death difference 320-300 = 20 is a typical deviation sqrt(320) = 18.)

All the other smoking trials are randomized comparisons of whole packages of lifestyle advice; smoking is only one part of the package.  The most recent such trial was MRFIT;

The MRFIT design called for the recruitment of at least 12,000 men aged 35 to 57 years who were at increased risk of death from CHD [heart attack], but had no clinical evidence of CHD. Persons were designated at “increased risk” if their levels of three risk factors-cigarette smoking, serum cholesterol, and blood pressure (BP)-were sufficiently high at a first screening visit to place them in the upper 15% of a risk score distribution based on data from the Framingham Heart Study.  After about one third of the screening was completed and success in recruitment had been demonstrated, the 15% was changed to 10%.

Out of 8000 smokers, a random half were advised to quit smoking, and more of them did quit:

4,103 special intervention [SI] and 4,091 usual care [UC] men … reported smoking cigarettes at the first screening visit. Among SI men, the reported cessation rate increased from 43.1% at 12 months to 48.9% at 72 months. The reported cessation rate among UC men increased from 13.5% at 12 months to 28.8% at 72 months. Among smokers who reported cessation at 72 months, 51.3% of SI men and 22.7% of UC men had quit smoking within the first year and remained abstinent thereafter. Average thiocyanate and expired-air carbon monoxide served as objective measures of smoking and were significantly lower among the special intervention men.

Within each half of the experiment, the study did see strong correlations between death and smoking:

For both SI and UC men, substantial differences in subsequent CHD (34-49%) and all-cause (35-47%) mortality were evident for men who reported cigarette smoking cessation by the end of the trial compared with those continuing to smoke.

But comparing the two halves, we find that smoking less has no observed effect on lung cancer deaths:

After 16 years of follow-up, lung cancer mortality rates were higher in the SI than in the UC group … 135 SI and 117 UC participants died from lung cancer.  … None of the hypotheses proposed to explain the unexpected higher rates of lung cancer mortality among SI as compared with UC subjects were sustained by the data.

Nor were there significant overall mortality effects from the entire package of advice:

After 16 years … 991 SI and 1050 UC men had died by the end of follow-up (relative difference, -5.7%; 95% CI, -13% to 2.8%)..

Again, those who smoked less died about 6% less (though more of lung cancer), but this difference still isn’t 5% significant.

The other studies are older, and harder to find.  (Can anyone get copies of these papers: EHJ83, Lancet86, EHJ86, AnnMed92?)   I did find this one:

In a randomized five-year multifactorial primary prevention trial of vascular diseases, hyperlipidemias, hypertension, smoking, obesity, and abnormal glucose tolerance of the high-risk test group (n=612 men) were treated with dietetic-hygienic measures and hypolipidemic (mainly probucol and clofibrate) and antihypertensive (mainly diuretics and β-blockers) agents.  [There was] a matched high-risk control group (n=610) … Despite the highly significant reduction in the risk factor level, the five-year intervention program did not reduce coronary mortality or morbidity. In fact, the number of total coronary events tended to be higher in the intervention group than in the control group (19 vs nine cases; P=.057).

Bottom line: when folks freely choose if to smoke, we see strong correlations between death and smoking.  The simple correlation is that smokers die about 60-70% more often, but after controlling for a few other factors this drops to 20-40%.   Yet when a randomized trials selects 8000 of the 10% highest risk smokers, and induces half of them to smoke less, so that 49% instead of 29% quit smoking by seven years, that half dies only 6% less over 16 years, and dies more of lung cancer.

Now if that entire 6% drop were real and due entirely to one half smoking 20% less, that would translate into a roughly 30% smoking mortality effect.  So if we assume high risk smokers aren’t hurt more by smoking than other smokers, we aren’t quite at the point of seeing a clear contradiction.  Apparently we need bigger trials if we are going to see clearly if smoking kills on net.   Alas the era of the large risk trial seems to be over, at least for now; it seems it will be a long time before we really know.

William Napier

But I still would not have heard of Napier had I not read his two brilliant 2007 Astrobiology papers, published when he was 67.  The first argued comets were a likely origin of life:

A single comet of radius 10 km … contains [about] as much clay … as … early Earth. … Our Solar System is surrounded by about 10¹¹ comets … A cometary interior provides a stable, aqueous, organic-rich environment for around 10⁶ years.

The second showed that life could spread across a galaxy when via giant molecular clouds reliably collecting life from the stars they drift near, and then passing that life on to a few of the thousands of new stars they create.  I now honor Napier by quoting lots of his detail:

The Solar System passes within 5 pc of star-forming nebulae every 50–100 million years, a distance which can be bridged by protected micro-organisms ejected from the Earth by impacts. Such encounters disturb the Oort cloud, and induce episodes of bombardment of the Earth and the ejection of microbiota from its surface. Star-forming regions within the nebulae encountered may thus be seeded by significant numbers of microorganisms. … Dissemination of microbiota proceeds most rapidly through the molecular ring of the Galaxy. …

The Oort cloud comprises perhaps 10¹¹ comets at distances up to 50,000 AU from the sun, with orbital periods up to ~4 Myr. The mass of the system probably lies in the range 0.1–250 Earth masses.  … Surges in flux (‘ comet showers ’ …) are expected owing to discrete perturbations of the Oort cloud. Giant molecular clouds have masses characteristically M~5 x 10⁵ Msun.  ….  The bombardment profile resulting from a grazing encounter with a [500K Msun] GMC [Giant Molecular Cloud], an event which has probably happened five to ten times in Solar System history. … [has] a distinct bombardment episode, declining with a half-width ~3 Myr.  …

Bombardment episodes can be seen with some degree of statistical confidence in the terrestrial impact record of the past 250 million years. … A weak periodicity does seem to be present … The periodicity may be ~36 Myr … It likely has a Galactic provenance, consistent with the Sun’s vertical motion through the Galactic disc and the tendency for nebulae to be concentrated towards the plane. …

In the inner planetary system, … a 1 m boulder would be destroyed by erosion in 19,000 to 230,000 yr. …  Metre-sized boulders ejected from Earth may then be collisionally reduced to submicrometre particles on timescales of a few centuries, whereupon Solar radiation pressure will expel them from the Solar System. … The meteoroid attains a terminal velocity v ~13 km/s and travels 1.9 pc from the Solar System in 140,000 years. … A 1 mm grain with a graphite coat 0.02 mm thick would achieve this. This timescale may be compared with the half-life of deep-frozen microbiota against destruction by Galactic cosmic rays, which according to Mileikowsky et al. (2000) is ~75 000 yr for some micro-organisms. Thus a significant fraction of microbiota would survive exposure to Galactic cosmic rays while travelling out to a few parsecs from the Solar System (arguments have been given to suggest much longer survival times). The Galactic cosmic ray count within a GMC is low and will increase the half-life taken for the biosphere radius calculation.

The Solar System may thus be surrounded by a biosphere extending out to at least ~5 pc, capable of infecting a star-forming nebula during a close encounter. One readily finds that, conservatively, ~3 x 10¹⁵ g of unshocked surface material from the Earth is injected into the GMC during the ~3 Myr of the passage. Furthermore, as this material is largely in micrometre-sized particles, … If there are 10⁶ microorganisms per gram of terrestrial material ejected, …

Massive nebulae are scavengers, disturbing the comet clouds of star systems penetrating them and gathering up the expelled dust, which will include any microbiota ejected in unshocked planetary material. A typical GMC may have ~50 000 stars passing through it at any time. They are also sites of star and planet formation (an OB association may contain several thousand stars) and so there is a clear potential for propagating life throughout the Galaxy as a chain reaction. …

Diffusion of life throughout the Galactic habitable zone would proceed most rapidly through the molecular ring of the Galaxy and spread from there. The mean interval between significant encounters in the ring is ~50 Myr. In the ring, only 1.12 habitable planets or their precursor material need be inoculated per encounter with a molecular cloud for panspermia to go to completion within the age of the Galaxy. Two inoculations per encounter would lead to complete dissemination in less than 400 Myr.

Some criticism of these papers here, which noted:

The [Falkowski] team recovered highly degraded microbial DNA from 8 million-year-old Antarctic ice and estimated that DNA on Earth has a half-life of only about 1.1 million years. In other words, every 1.1 million years, half of the DNA disappears.

But see also this elaboration by Chandra Wickramasinghe, and this confirmation of the comet claims:

Liquid water in comets, once considered impossible, now appears to be almost certain.
New evidence has come from the discovery of clay minerals in comet Tempel 1, which compliments the indirect evidence in aqueous alteration of carbonaceous chondrites. Infrared spectral indication of clay is confirmed by modelling data.

See also these suspiciously red comets, and Richard Hoover’s picts and vid of suspiciously lifelike materials in an older-than-Earth meteorite.

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