Category: Science

The culture that is Japan markets in everything

by  Tyler Cowen in

Uguisu no Fun’s main effect – that being bleaching and exfoliating the skin – is a result of Guanine, a naturally occurring enzyme found in nightingale droppings. Kabuki actors and high-ranking geisha girls have always prized it as the best way to remove their heavy makeup while leaving their high-priced skin smooth and supple.

The link with photos is here and for the pointer I thank Scott Rogers.

Should computers have their own websites?

by  Tyler Cowen in

I think so, if not now very soon:

Websites designed to be read by computers rather than humans could make it easier to share and use data says Stephen Wolfram, creator of “computational knowledge engine” Wolfram Alpha. Writing in a blog post, he suggests that “.data” should join the likes of .com, .org and .net as a new top-level domain (TLD) for organisations to share data in a standard from, creating a “data web” that would run in parallel with the ordinary web.

Under Wolfram’s scheme, a website like wolfram.com would be accompanied by wolfram.data. A human visitor to wolfram.data would just see a list of publicly available databases, but a computer would be able to access and interact with the data itself.

Of course, this kind of data sharing is already possible thanks to application programming interfaces (APIs), the software instructions published by many web services that allow programmers to combine data in creative ways, such as plotting Twitter updates on a Google map. Each organisation’s API is different though, which can make them hard to use. Wolfram’s proposal would put data in a standard location and format, making it easier to access.

For the pointer I thank Michelle Dawson.

*The Sounding of the Whale*

by  Tyler Cowen in

For now, suffice it to say that a kind of tragedy haunts the story of whale biology in the first half of the twentieth century: the science that developed between 1910 and 1940 for the purpose of protecting whale populations from excessive exploitation by whalers became, along the way, a science so deeply entangled with the whaling industry — dependent upon it, bound to it, acculturated to its physical labor, and finally, constituted on its operations — as to become, finally, nothing less than an obstacle to many conservation policies.  It was a reasonably complete science of whales but was ultimately incapable of realizing the aims of its founders: checking the progressive destruction of the world’s large cetaceans.

That is from D. Graham Burnett’s very impressive The Sounding of the Whale: Science and Cetaceans in the Twentieth Century.  Here is a NYT review, and here is a WSJ review.  It could be the most detailed study of a commons problem ever written, with plenty on the corruption of science along the way.

Paging Dr. Siri

by  Alex Tabarrok in

In 2004 I wrote In Praise of Impersonal Medicine arguing:

I have nothing against my physician but I would prefer to be diagnosed by a computer.  A typical physician spends most of the day playing twenty questions. Where does it hurt?  Do you have a cough?  How high is the patient’s blood pressure?  But an expert system can play twenty questions better than most people.  An expert system can use the best knowledge in the field, it can stay current with the journals, and it never forgets.

and in 2006 I noted:

The practice of modern medicine is surprisingly primitive…My credit card company knows far more about my shopping history than my physician knows about my medical history.

I now believe that we are on the cusp of major changes to medicine. The thousand dollar genome sequence is less than a year away, Ford has just developed a car seat that can monitor your health, many people are already using wrist monitors to measure heart and sleep patterns. All of this data will soon be combined with massive databases to offer predictive and prescriptive health diagnosis.

In Do We Need Doctors or Algorithms the venture capitalist Vinod Khosla expands:

IBM’s Watson computer… is now being applied to medical diagnosis after handling imprecise and vague tasks like winning at Jeopardy, which experts a few years ago would have said could not be done. “Computers cannot match the judgment of humans on these kinds of tasks!” And with enough data, medical diagnosis or 90% of it is an easier task than Jeopardy.

Already Kaiser Permanent already has 10 million real-time medical records with details of 30,000,000 e-visits last year with caregivers and computer modeling of key diseases per individual that data scientists would love to get their hand on. Already, according to IDC 14% of the US population is using their phones for medical help and 200 million health and fitness related mobile applications have been downloaded according to pyramid research. Fun stuff, though early. They are probably two generations away from systems that are actually useful.

…But I doubt very much if within 10-15 years (given continued investment and innovation and keeping the AMA from quashing such efforts politically) I won’t be able to ask Siri’s great great grandchild (Version 9.0?) for an opinion far more accurate than the one I get today from the average physician. Instead of asking Siri 9.0, “I feel like sushi” or “where can I dispose a body” (try it…it’s fairly accurate!) and with your iPhone X or Android Y with all the power of IBM’s current Watson computer in the mobile phone and an even more powerful “Nvidia times 10-100” server which will cost far less than med school with terabytes or petabytes of data on hundreds of millions (billions?) of patients, including their complete genomics and proteomics (each sample costing about the same as a typical blood test).

Facts about engines

by  Tyler Cowen in

The RMS Titanic weighed almost 50,000 tons and could carry 3,500 people. Before it sunk, it was world-famous as the massive titan of the sea. Its multiple engines, powered by 159 coal furnaces, were designed to deliver 46,000 horsepower.

Compare that to today’s beastly mode of transport: the Boeing 777. Bangalore Aviation points out that a single GE90-115B engine puts out over 110,000 horsepower, or more than twice the design output of all the Titanic’s steam engines.

And that power is obviously hooked up to a much smaller vehicle. The Titanic had to carry 14,000,000 pounds of coal alone; the 777 has a total weight of only 775,000 pounds.

Here is more and for the pointer I thank Roland Stephen.

Andrew Lo reviews 21 books on the financial crisis

by  Tyler Cowen in

The paper and abstract are here:

Abstract:
The recent financial crisis has generated many distinct perspectives from various quarters. In this article, I review a diverse set of 21 books on the crisis, 11 written by academics, and 10 written by journalists and one former Treasury Secretary. No single narrative emerges from this broad and often contradictory collection of interpretations, but the sheer variety of conclusions is informative, and underscores the desperate need for the economics profession to establish a single set of facts from which more accurate inferences and narratives can be constructed.

It is an instructive look at how bad we are at discovering the truth and talking about it.  Here is part of his beginning:

To illustrate just how complicated it can get, consider the following “facts” that have become part of the folk wisdom of the crisis:

1. The devotion to the Efficient Markets Hypothesis led investors astray, causing them to ignore the possibility that securitized debt2 was mispriced and that the real-estate bubble could burst.

2. Wall Street compensation contracts were too focused on short-term trading profits rather than longer-term incentives. Also, there was excessive risk-taking because these CEOs were betting with other people’s money, not their own.

3. Investment banks greatly increased their leverage in the years leading up to the crisis, thanks to a rule change by the U.S. Securities and Exchange Commission (SEC).

While each of these claims seems perfectly plausible, especially in light of the events of 2007–2009, the empirical evidence isn’t as clear.

Starting on p.35, you can find a new take on the myth of the 2004 SEC change to Rule 15c3–1 (though see the first comment), relating to the supposed increase in leverage requirements from 12-1 to 33-1:

…it turns out that the 2004 SEC amendment to Rule 15c3–1 did nothing to change the leverage restrictions of these financial institutions. In a speech given by the SEC’s director of the Division of Markets and Trading on April 9, 2009 (Sirri, 2009), Dr. Erik Sirri stated clearly and unequivocally that “First, and most importantly, the Commission did not undo any leverage restrictions in 2004”. He cites several documented and verifiable facts to support this surprising conclusion, and this correction was reiterated in a letter from Michael Macchiaroli, Associate Director of the SEC’s Division of Markets and Trading to the General Accountability Office (GAO) on July 17, 2009, and reproduced in the GAO Report GAO–09–739 (2009, p. 117).

It is also shown that the higher leverage was common in the late 1990s.  There is more to the discussion, but it is time to reconsider this point.

Where are they?

by  Tyler Cowen in

Hey, you!  Do you ever leave comments on MR?

NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet’s surface, but they are the smallest exoplanets ever confirmed around a star like our sun.

The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1,000 light-years away in the constellation Lyra.

The link is here and for the pointer I thank Bernard Guerrero.

Markets in everything: the market for magic tricks

by  Tyler Cowen in

Allen’s new new crop are the Internet magicians. “They’ve got a different approach and different goals. I’m not sure they even want to develop an act that they can perform live; they’re interested in making videos that go viral. From my viewpoint, it’s not a problem so much as it’s an interesting evolution.”

The full story is here, and for the pointer I thank Mark Thorson.

Science

by  Tyler Cowen in

The latest rumour is that both ATLAS and CMS have evidence that the Higgs mass is about 125 GeV/C2 at confidence levels of 3.5σ and 2.5σ respectively. At 3.5σ, the measurement could be the result of a random fluke just 0.1% of the time whereas at 2.5σ the fluke factor is about 1%.

If you are really optimistic, I believe you can add these two results together in quadrature to get an overall result with a significance of 4.3σ.

While these might sound like fantastic odds to you and me, particle physicists normally wait until they have a confidence of 5σ or greater before they call it a “discovery”. Anything over 3σ is described as “evidence”.

…Crease wisely cites past experience as the number-one reason for caution. Indeed he quotes University of Oxford physicist and data-analysis guru Louis Lyons as saying “We have all too often seen interesting effects at the 3σ or 4σ level go away as more data are collected.”

As Crease points out, nearly everyone he spoke to in writing his article “had tales – many well known – of signals that went away, some at 3σ: proton decay, monopoles, the pentaquark, an excess at Fermilab of high-transverse-momentum jets”.

Here is more, and for the pointer I thank Ken Regan.  Here are the InTrade markets, which are pricing observation before 2014 at 88.

We now return to your regularly scheduled programming.

Small samples mean statistically significant results should usually be ignored

by  Alex Tabarrok in
Size really matters: prior to the era of large genome-wide association studies, the large effect sizes reported in small initial genetic studies often dwindled towards zero (that is, an odds ratio of one) as more samples were studied. Adapted from Ioannidis 2001 et al., Nat Genet 29:306-309.

Genomes Unzipped: In October of 1992, genetics researchers published a potentially groundbreaking finding in Nature: a genetic variant in the angiotensin-converting enzyme ACE appeared to modify an individual’s risk of having a heart attack. This finding was notable at the time for the size of the study, which involved a total of over 500 individuals from four cohorts, and the effect size of the identified variant–in a population initially identified as low-risk for heart attack, the variant had an odds ratio of over 3 (with a corresponding p-value less than 0.0001).

Readers familiar with the history of medical association studies will be unsurprised by what happened over the next few years: initial excitement (this same polymorphism was associated with diabetes! And longevity!) was followed by inconclusive replication studies and, ultimately, disappointment. In 2000, 8 years after the initial report, a large study involving over 5,000 cases and controls found absolutely no detectable effect of the ACE polymorphism on heart attack risk.

The ACE story is not unique to the ACE polymorphism or to medical genetics; the problem is common to most fields of empirical science. If the sample size is small then statistically significant results must have big effect sizes. Combine this with a publication bias toward statistically significant results, plenty of opportunities to subset the data in various ways and lots of researchers looking at lots of data and the result is diminishing effects with increasing confidence, as beautifully shown in the figure.

For more see my post explaining Why Most Published Research Findings are False and Andrew Gelman’s paper on the statistical challenges of estimating small effects.

Addendum: Chris Blattman does his part to reduce bias. Will journal editors follow suit?

Gratitude

by  Alex Tabarrok in

PsycNet: The effect of a grateful outlook on psychological and physical well-being was examined. In Studies 1 and 2, participants were randomly assigned to 1 of 3 experimental conditions (hassles, gratitude listing, and either neutral life events or social comparison); they then kept weekly (Study 1) or daily (Study 2) records of their moods, coping behaviors, health behaviors, physical symptoms, and overall life appraisals. In a 3rd study, persons with neuromuscular disease were randomly assigned to either the gratitude condition or to a control condition. The gratitude-outlook groups exhibited heightened well-being across several, though not all, of the outcome measures across the 3 studies, relative to the comparison groups. The effect on positive affect appeared to be the most robust finding. Results suggest that a conscious focus on blessings may have emotional and interpersonal benefits.