Category: Science
A correction from *Nature*
Corrected: In the original text, we wrongly attributed to Enrico Spolaore the opinion that using genetic data in economics could help policy-makers to set immigration levels. He actually suggested that the work could reduce barriers to the flows of ideas and innovations across populations. The text has been amended to reflect that.
The link is here. The earlier MR post is here. I thank a loyal MR reader for the pointer.
Controversies over economics and genetics
To critics, the economists’ paper seems to suggest that a country’s poverty could be the result of its citizens’ genetic make-up, and the paper is attracting charges of genetic determinism, and even racism. But the economists say that they have been misunderstood, and are merely using genetics as a proxy for other factors that can drive an economy, such as history and culture. The debate holds cautionary lessons for a nascent field that blends genetics with economics, sometimes called genoeconomics. The work could have real-world pay-offs, such as helping policy-makers to set the right level of immigration to boost the economy, says Enrico Spolaore, an economist at Tufts University near Boston, Massachusetts, who has also used global genetic-diversity data in his research.
But the economists at the forefront of this field clearly need to be prepared for harsh scrutiny of their techniques and conclusions. At the centre of the storm is a 107-page paper by Oded Galor of Brown University in Providence, Rhode Island, and Quamrul Ashraf of Williams College in Williamstown, Massachusetts. It has been peer-reviewed by economists and biologists, and will soon appear in American Economic Review, one of the most prestigious economics journals.
The full story is here. The previous MR post on the dispute, which includes a link to the paper, is here.
What’s the chance of rain?
…the for-profit weather forecasters rarely predict exactly a 50 percent chance of rain, which might seem wishy-washy and indecisive to consumers. Instead, they’ll flip a coin and round up to 60, or down to 40, even though this makes the forecasts both less accurate and less honest.
That is from Nate Silver’s new and excellent The Signal and the Noise: Why So Many Predictions Fail — But Some Don’t. The profile of Robin Hanson appears on p.201.
Truth Bounties
The Truth Market is an interesting combination of prediction markets, bounty hunting and crowd funding that aims to separate the wheat from the chaff of truth claims. Here is how it works:
You hear a statement that you think is bogus (or you hear the denial of something that you think is true). You open a challenge in which you offer to pay a truth bounty of $x if someone can prove that the bogus statement is true (or prove false the statement that you think is true). Other people can join your challenge, adding to the bounty. If the total bounty exceed a significant threshold the challenge goes live.
Once a challenge is live, anyone can earn the bounty if their evidence for or against the claim meets the standards of a neutral, professional, scientifically trained group of adjudicators (provided by TruthMarket). If within a given time-frame no one wins the bounty the bounties are returned to the contributors minus 20% which goes to the initial sponsor of the challenge. The initial sponsor can now also trumpet that despite significant cash no one was able to prove the bogus claim (or refute the true claim).
Thus, there are incentives to offer challenges, incentives to answer challenges, and incentives to pay attention to the results. TruthMarket has some serious people on its management team and advisory board. There are already challenges about global warming, cell phones, defensive gun use and other issues.
Will the Truth Market work? In order to work, TruthMarket will need a track record of significant money bounties and adjudicated claims. As of yet, I don’t see many (any? the site is unclear although this is the most important part of the process).
Most important, people have to regard winning a bounty and the failure to win a bounty as informative. My experience, however, is that the people who regard betting as informative are already rational and well-informed about other issues so the bounty isn’t necessary to prosecute the truth claim.
The Amazing Randi’s one million dollar prize for “evidence of any paranormal, supernatural, or occult power or event,” was first offered in 1964 but has never been claimed. In theory, that tells us a lot. In practice, the failure of the prize to be won does not seem to have changed many people’s beliefs.
Study of investment diversification on the UC-Berkeley campus
That’s a header from the excellent Mark Thorson. Here is an excerpt:
“Think of them as little bankers depositing money and spreading it out in different funds, and doing some management of those funds,” said Mikel Delgado, a doctoral student in psychology who heads the squirrel research team in the laboratory of UC Berkeley psychologist Lucia Jacobs.
Here is another good squirrel sentence:
“Despite her disability, she’s great at caching,” said Delgado.
And this:
…squirrels shake their heads to assess the quality of the nut, and that this “head-flicking behavior” increases when they plan to store the nut rather than eat it.
Finally, unlike many of us:
While Delgado hopes to crack the mystery of which cognitive navigation skills squirrels use to find their personal stashes, one thing’s for sure: “They’re saving for the future,” she said, “and they’re really smart about it.”
The story is here.
China’s Solyndra Problem
The NYTimes reports that China has a much bigger Solyndra problem than the United States ever did:
…China’s strategy is in disarray. Though worldwide demand for solar panels and wind turbines has grown rapidly over the last five years, China’s manufacturing capacity has soared even faster, creating enormous oversupply and a ferocious price war.
The result is a looming financial disaster, not only for manufacturers but for state-owned banks that financed factories with approximately $18 billion in low-rate loans and for municipal and provincial governments that provided loan guarantees and sold manufacturers valuable land at deeply discounted prices.
China’s biggest solar panel makers are suffering losses of up to $1 for every $3 of sales this year, as panel prices have fallen by three-fourths since 2008. Even though the cost of solar power has fallen, it still remains triple the price of coal-generated power in China, requiring substantial subsidies through a tax imposed on industrial users of electricity to cover the higher cost of renewable energy.
This bit also seemed familiar:
Mr. Li said in an interview that he wanted banks to cut off loans to all but the strongest solar panel companies and let the rest go bankrupt. But banks — which were encouraged by Beijing to make the loans — are not eager to acknowledge that the loans are bad and take large write-offs, preferring to lend more money to allow the repayment of previous loans. Many local and provincial governments also are determined to keep their hometown favorites afloat to avoid job losses and to avoid making payments on loan guarantees, he said.
Looking at pictures of cute animals makes you work more carefully and deliberately
A new study by Japanese researchers now shows there are more benefits to looking at pictures of these universal delights than just getting a case of the warm and fuzzies. Afterwards, we concentrate better.
Such is the “Power of Kawaii”, as a paper documenting the research is appropriately titled. The Japanese word “kawaii” means cute. The paper was published in the online edition of the U.S. journal Plos One on Thursday. Through three separate experiments a team of scientists from Hiroshima University showed that people showed higher levels of concentration after looking at pictures of puppies or kittens.
For the pointer I thank Mark Thorson.
In which they fail to credit Miss A. Elk
“Why sauropods had long necks; and why giraffes have short necks”
The necks of the sauropod dinosaurs reached 15 m in length: six times longer than that of the world record giraffe and five times longer than those of all other terrestrial animals. Several anatomical features enabled this extreme elongation, including: absolutely large body size and quadrupedal stance providing a stable platform for a long neck; a small, light head that did not orally process food; cervical vertebrae that were both numerous and individually elongate; an efficient air-sac-based respiratory system; and distinctive cervical architecture. Relevant features of sauropod cervical vertebrae include: pneumatic chambers that enabled the bone to be positioned in a mechanically efficient way within the envelope; and muscular attachments of varying importance to the neural spines, epipophyses and cervical ribs. Other long-necked tetrapods lacked important features of sauropods, preventing the evolution of longer necks: for example, giraffes have relatively small torsos and large, heavy heads, share the usual mammalian constraint of only seven cervical vertebrae, and lack an air-sac system and pneumatic bones. Among non-sauropods, their saurischian relatives the theropod dinosaurs seem to have been best placed to evolve long necks, and indeed they probably surpassed those of giraffes. But 150 million years of evolution did not suffice for them to exceed a relatively modest 2.5 m.
The link is here, and for the pointer I thank Michelle Dawson. The inspiration for this paper can be found here.
The half-life of an economics book
9.38 years, measured in terms of citations over time.
That is from the new and excellent book by Samuel Arbesman, The Half-Life of Facts:Why Everything We Know Has an Expiration Date.
Guns don’t kill people, printers do!
Imagine an America in which anyone can download and print a gun in their own home. They wouldn’t need a license, a background check, or much technical knowledge, just a 3D printer. That’s the vision a cadre of industrious libertarians are determined to turn into reality.
Last week, Wiki Weapon, a project to create the first fully printable plastic gun received the $20,000 in funding it needed to get off the ground. The project’s goal is not to develop and sell a working gun, but rather to create an open-source schematic (or blueprint) that individuals could download and use to print their own weapons at home.
The technology that makes this possible is 3D printing, a process during which plastic resin is deposited layer by layer to create a three dimensional object. In the past few years 3D printers have become increasingly affordable, and just last week the first two retail stores selling 3D printers opened in the United States with models ranging from $600 to $2,199.
Here is more.
What is the smallest prime?
From Chris K. Caldwell and Yeng Xiong:
What is the first prime? It seems that the number two should be the obvious answer, and today it is, but it was not always so. There were times when and mathematicians for whom the numbers one and three were acceptable answers. To find the first prime, we must also know what the first positive integer is. Surprisingly, with the definitions used at various times throughout history, one was often not the first positive integer (some started with two, and a few with three). In this article, we survey the history of the primality of one, from the ancient Greeks to modern times. We will discuss some of the reasons definitions changed, and provide several examples. We will also discuss the last significant mathematicians to list the number one as prime.
The paper is here, hat tip goes to Natasha Plotkin.
Fox and Mitchum on the Flynn Effect and how it works
James R. Flynn recommends this paper, by Fox and Mitchum, in his new book:
Secular gains in intelligence test scores have perplexed researchers since they were documented by Flynn (1984, 1987). Gains are most pronounced on abstract, so-called culture-free tests, prompting Flynn (2007) to attribute them to problem solving skills availed by scientifically advanced cultures. We propose that recent-born individuals have adopted an approach to analogy that enables them to infer higher-level relations requiring roles that are not intrinsic to the objects that constitute initial representations of items. This proposal is translated into item-specific predictions about differences between cohorts in pass rates and item-response patterns on the Raven’s Matrices, a seemingly culture-free test that registers the largest Flynn effect. Consistent with predictions, archival data reveal that individuals born around 1940 are less able to map objects at higher levels of relational abstraction than individuals born around 1990. Polytomous Rasch models verify predicted violations of measurement invariance as raw scores are found to underestimate the number of analogical rules inferred by members of the earlier cohort relative to members of the later cohort who achieve the same overall score. The work provides a plausible cognitive account of the Flynn effect, furthers understanding of the cognition of matrix reasoning, and underscores the need to consider how test-takers select item responses.
The paper is here (pdf).
From a loyal MR reader
I read through the Heckman debate. He does what he always does. One response is terrible (quality of early intervention doesn’t matter, just do a lot of it) but most of them make decent points. Carol Dweck hints at the problem of writing people off.
No one considers neurodiversity. No one considers that many successful people take big risks, follow their impulses, fail to comply, have bad habits, and otherwise misbehave. Heckman himself may be an example.
The Flynn Effect in East Germany
Economic, Educational, and IQ Gains in Eastern Germany 1990-2006 (gated), Eka Roivainen, Intelligence, Nov/Dec 2012
Abstract: Lynn and Vanhanen (2012) have convincingly established that national IQs correlate positively with GDP, education, and many other social and economic factors. The direction of causality remains debatable. The present study re-examines data from military psychological assessments of the German federal army that show strong IQ gains of 0.5 IQ point per annum for East German conscripts in the 1990s, after the reunification of the country. An analysis of IQ, GDP, and educational gains in 16 German federal states between 1990 and 1998 shows that IQ gains had a .89 correlation with GDP gains and a .78 correlation with educational gains. The short time frame excludes significant effects of biological or genetic factors on IQ gains. These observations suggest a causal direction from GDP and education to IQ.
For the pointers I thank Michelle Dawson and Ron Unz.
The new Oded Galor and Quamrul Ashraf paper
Here is from an editorial summary published in Science (gated):
…Ashraf and and Galor present the hypothesis that genetic diversity has exerted a long-lasting effect on economic development—which is quantified as population density in the precolonial era and as per-capita income for contemporary nations—beyond the influences of geography, institutions, and culture. They posit that intermediate levels of heterozygosity allow for a productive balance between the social costs of high diversity and the creative benefits of higher variance in cognitive skills. They show that the optimal level of diversity was approximately 0.68 in 1500 CE, and that this increased to 0.72 (which is pretty much where the United States sits) in the year 2000, with the most homogeneous country, Bolivia, placed at 0.63 and the most diverse country, Ethiopia, at 0.77. Just how large an effect are we talking about? They estimate that genetic diversity accounts of 16% of the cross-country dispersion in per-capita income; put in another way, shifting the diversity of the United States higher or lower by one percentage point would decrease per-capita income by 1.9%.
One version of the paper is here, and it will be coming out in the American Economic Review. Being on the road, I have yet to read this work.