They used to say this couldn’t be done:

We construct genomic predictors for heritable and extremely complex human quantitative traits (height, heel bone density, and educational attainment) using modern methods in high dimensional statistics (i.e., machine learning). Replication tests show that these predictors capture, respectively, ~40, 20, and 9 percent of total variance for the three traits. For example, predicted heights correlate ~0.65 with actual height; actual heights of most individuals in validation samples are within a few cm of the prediction. The variance captured for height is comparable to the estimated SNP heritability from GCTA (GREML) analysis, and seems to be close to its asymptotic value (i.e., as sample size goes to infinity), suggesting that we have captured most of the heritability for the SNPs used. Thus, our results resolve the common SNP portion of the “missing heritability” problem – i.e., the gap between prediction R-squared and SNP heritability. The ~20k activated SNPs in our height predictor reveal the genetic architecture of human height, at least for common SNPs. Our primary dataset is the UK Biobank cohort, comprised of almost 500k individual genotypes with multiple phenotypes. We also use other datasets and SNPs found in earlier GWAS for out-of-sample validation of our results.

While I don’t find “within a few centimeters” to be especially impressive, the question is still “what’s next?”

The authors on the paper are Louis Lello, Steven G Avery, Laurent Tellier, Ana Vazquez, Gustavo de los Campos, and Stephen D. H. Hsu.

Via Ben Schmidt, the term becomes common only in the 1970s:

I’d like to see a detailed look at actual journal practices, but my personal sense is that editorial review was the norm until fairly recently, not review by a team of outside referees.  In 1956, for instance, the American Historical Review asked for only one submission copy, and it seems the same was true as late as 1970.  I doubt they made the photocopies themselves. Schmidt seems to suggest that the practices of government funders nudged the academic professions into more formal peer review with multiple referee reports.

Further research is needed (how about we ask some really old people?), at least if peer review decides it is worthy of publication.  Frankly I suspect such work would stand a better chance under editorial review.

In the meantime, here is a tweet from the I didn’t know she was on Twitter Judy Chevalier:

I have just produced a 28-page “responses to reviewer and editor questions” for a 39-page paper.

I’d rather have another paper from Judy.

By the way, scientific papers are getting less readable.


Individuals experiencing extreme weather activity more likely to support climate adaptation policy.

Effect of extreme weather activity on opinion is modest and not consistent across specific adaptation policies.

Effect of extreme weather activity on opinion diminishes over time.

Here is the paper, via the excellent Kevin Lewis.

Social insect colonies are highly successful, self-organized complex systems. Surprisingly however, most social insect colonies contain large numbers of highly inactive workers. Although this may seem inefficient, it may be that inactive workers actually contribute to colony function. Indeed, the most commonly proposed explanation for inactive workers is that they form a ‘reserve’ labor force that becomes active when needed, thus helping mitigate the effects of colony workload fluctuations or worker loss. Thus, it may be that inactive workers facilitate colony flexibility and resilience. However, this idea has not been empirically confirmed. Here we test whether colonies of Temnothorax rugatulus ants replace highly active (spending large proportions of time on specific tasks) or highly inactive (spending large proportions of time completely immobile) workers when they are experimentally removed. We show that colonies maintained pre-removal activity levels even after active workers were removed, and that previously inactive workers became active subsequent to the removal of active workers. Conversely, when inactive workers were removed, inactivity levels decreased and remained lower post-removal. Thus, colonies seem to have mechanisms for maintaining a certain number of active workers, but not a set number of inactive workers. The rapid replacement (within 1 week) of active workers suggests that the tasks they perform, mainly foraging and brood care, are necessary for colony function on short timescales. Conversely, the lack of replacement of inactive workers even 2 weeks after their removal suggests that any potential functions they have, including being a ‘reserve’, are less important, or auxiliary, and do not need immediate recovery. Thus, inactive workers act as a reserve labor force and may still play a role as food stores for the colony, but a role in facilitating colony-wide communication is unlikely. Our results are consistent with the often cited, but never yet empirically supported hypothesis that inactive workers act as a pool of ‘reserve’ labor that may allow colonies to quickly take advantage of novel resources and to mitigate worker loss.

That is by Daniel Charbonneau, Takao Sasaki, and Anna Dornhaus, file under “speculative.”  For the pointer I thank Eric Durbrow.

There is now another paper on this theme by Nicholas Bloom, Charles I. Jones, John Van Reenen, and Michael Webb, abstract:

In many growth models, economic growth arises from people creating ideas, and the long-run growth rate is the product of two terms: the effective number of researchers and their research productivity. We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productivity is declining sharply. A good example is Moore’s Law. The number of researchers required today to achieve the famous doubling every two years of the density of computer chips is more than 18 times larger than the number required in the early 1970s. Across a broad range of case studies at various levels of (dis)aggregation, we find that ideas — and in particular the exponential growth they imply — are getting harder and harder to find. Exponential growth results from the large increases in research effort that offset its declining productivity.

Here is the NBER link.

I say no, but some disagree:

There hasn’t been an innovation in the world of chocolate since the white variant was introduced in 1930, which is fine because — in the immortal words of Cogsworth in “Beauty and the Beast” — if ain’t baroque, don’t fix it.

But still, we’d never turn away a new kind of creamy, chocolate-y thing to munch on while we binge-watch Netflix.

And thanks to some Swiss chocolate scientists over at Barry Callebaut — the world’s leading manufacturer of the good stuff, producing 1.8 million tons of cocoa every year and with a revenue of almost $10 billion — that’s exactly what we’re getting. A brand new chocolate flavor called Ruby, developed from the Ruby Cocoa bean, colored a pleasingly millennial pink hue and that tastes like sweet, sweet berries despite having no added color or flavoring.

“Ruby chocolate is the fourth type of chocolate [after milk, white and dark] and is an intense sensorial delight,” a spokesperson for Barry Callebaut said after launching the chocolate to a panel of experts in China.

Here is the (noisy) link, via the excellent Samir Varma.


by on September 8, 2017 at 12:19 pm in Economics, History, Medicine, Science | Permalink

Long ago, in the ancient city of Cyrene, there was a herb called silphium. It didn’t look like much – with stout roots, stumpy leaves and bunches of small yellow flowers – but it oozed with an odiferous sap that was so delicious and useful, the plant was eventually worth its weight in gold.

Image result for silphiumThat’s the opening to an excellent story about silphium, a herb widely-used and loved by the Romans but that hasn’t been seen for nearly two thousand years. Part of the problem was biological, the plant grew only in a tiny region of modern day Libya:

Its entire range consisted of a narrow strip of land about 125 miles (201km) by 35 miles (40km).

Try as they might, neither the Greeks or the Romans could work out how to farm it in captivity. Instead silphium was collected from the wild, and though there were strict rules about how much could be harvested, there was a thriving black market.

Even today there are plants, like huckleberry which resist all efforts to farm them. (Ala Jared Diamond’s Guns, Germs and Steel). Part of the problem was also economic–a tragedy of the commons–as prices shot up and property rights weren’t strong enough to prevent over-farming.

And might silphium still be found somewhere in remote regions of Libya? Read the whole thing.

…We also find evidence supporting short-term adaptation effects prior to a hurricane landfall. Our results show that the 67 percent improvement in hurricane forecasts over the past 60 years is associated with damages being 16-63 percent lower than they otherwise would have been. Accounting for outlying observations narrows this range to 16-24 percent.

That is from an Oxford working paper by Andrew Martinez.

The formal title of this important paper is “The Wind of Change: Maritime Technology , Trade , and Economic Development.”  One of the major findings is that if you consider 1850-1905, using conservative estimates, the introduction of the faster and more reliable steam ships was responsible for least half of the world trade boom during those years.

That was just published in the AER by Luigi Pascali.  Here is the abstract:

The 1870–1913 period marked the birth of the first era of trade globalization. How did this tremendous increase in trade affect economic development? This work isolates a causality channel by exploiting the fact that the introduction of the steamship in the shipping industry produced an asymmetric change in trade distances among countries. Before this invention, trade routes depended on wind patterns. The steamship reduced shipping costs and time in a disproportionate manner across countries and trade routes. Using this source of variation and novel data on shipping, trade, and development, I find that (i) the adoption of the steamship had a major impact on patterns of trade worldwide; (ii) only a small number of countries, characterized by more inclusive institutions, benefited from trade integration; and (iii) globalization was the major driver of the economic divergence between the rich and the poor portions of the world in the years 1850–1900.

Here are ungated copies.

Flooded Cities

by on September 1, 2017 at 12:35 am in Data Source, History, Science, Uncategorized | Permalink

That is the title of a recent research paper (pdf) by Adriana Kocornik-Mina, Thomas K.J. McDermott, Guy Michaels, and Ferdinand Rauch.  Here is the abstract:

Does economic activity relocate away from areas that are at high risk of recurring shocks? We examine this question in the context of floods, which are among the costliest and most common natural disasters. Over the past thirty years, floods worldwide killed more than 500,000 people and displaced over 650,000,000 people. This paper analyzes the effect of large scale floods, which displaced at least 100,000 people each, in over 1,800 cities in 40 countries, from 2003-2008. We conduct our analysis using spatially detailed inundation maps and night lights data spanning the globe’s urban areas. We find that low elevation areas are about 3-4 times more likely to be hit by large floods than other areas, and yet they concentrate more economic activity per square kilometer. When cities are hit by large floods, the low elevation areas also sustain more damage, but like the rest of the flooded cities they recover rapidly, and economic activity does not move to safer areas. Only in more recently populated urban areas, flooded areas show a larger and more persistent decline in economic activity. Our findings have important policy implications for aid, development and urban planning in a world with rapid urbanization and rising sea levels.

One possible implication of these strong results is that, better pricing of flood insurance, which I favor, still probably won’t get most population centers out of those low-lying, relatively vulnerable areas.

That is the topic of my latest column from Bloomberg, here is one excerpt:

If you could directly alter your kids’ genetic profile, what would you want? It’s hard to know how the social debate would turn out after years of back and forth, but I was dismayed to read one recent research paper by psychologists Rachel M. Latham and Sophie von Stumm. The descriptive title of that work, based on survey evidence, is “Mothers want extraversion over conscientiousness or intelligence for their children.” Upon reflection, maybe that isn’t so surprising, because parents presumably want children who are fun to spend time with.

Would a more extroverted human race be desirable, all things considered? I genuinely don’t know, but at the very least I am concerned. The current mix of human personalities and institutions is a delicate balance which, for all of its flaws, has allowed society to survive and progress. I’m not looking to make a big roll of the dice on this one.

It’s also not difficult to imagine parents wanting children who are relatively well-behaved. The same research paper found that mothers, after extroversion, preferred the trait of “agreeableness” in their children, again over both intelligence and conscientiousness.

I was struck by a recent Chinese report that some parents are asking for children who are able to drink socially, for business purposes, and thus trying to avoid some genes that make it difficult to process alcohol. Caveat emptor.

Best sentence: “I don’t trust people to take so much control over the future of human nature.”

Tim reaffirms his status as one of the great (greatest?) contemporary popular writers on economics, this time turning his attention to technology.  From a Smithsonian interview:

So what made you decide to write a book looking at the modern economy through specific inventions? 

I think it was a slight sense of frustration. I’m an economist, and economics often feels abstract and very impersonal, even though I don’t think it’s abstract or impersonal. As an economics writer, I’m also looking for a way to tell a good story and get some ideas across. I realized if I produced a kind of technological history with lots of ideas and examples I could teach some economics lessons through these very specific stories.

What’s your favorite invention in the book?

It varies, but right now it’s paper. I just loved the realization that there was an alternative to talking about the Gutenberg press. Obviously I have nothing but admiration for the Gutenberg press – it’s a tremendously important innovation. But everybody told me, ‘oh, you’ve doing fifty inventions that shaped the world, you must do the Gutenberg press.’ And I thought, ‘yeah, but it’s so obvious.’ Then I was looking at the Gutenberg Bible in the New York Public Library, and thinking, ‘this bible is printed on something. It’s not printed on nothing. It’s printed on a surface.’ It turns out that the Gutenberg press works perfectly well with parchment, technologically speaking, but economically speaking it doesn’t make any sense without paper. Parchment is just too expensive to produce a long print run. So as long as all you’re doing is handwriting bibles and making them look beautiful, there’s no need to use paper at all. But with paper you’ve got a mass-produced writing surface. It’s often the very cheap inventions that get overlooked, but nevertheless change the world.

Here is an adaptation from the book on the history of barbed wire.  Here is another BBC adaptation on why electricity did not change manufacturing more quickly.  You can pre-order the book here.

I recall the eclipse in 1973.  As a kid, I made some kind of cardboard box, so I could view the sun through a little squinting hole.  The entire event was a big disappointment, even given the fact that, at the time, I had hardly seen anything before.  I hadn’t even been to Philadelphia.

I’ve seen it get dark before.  So is it special because we wonder how the others will react?  If traffic will freeze up and wild animals will burrow into the sleep holes for the night?  Or do we care simply because it is rare and publicly observable?  (NB: It is the 3 billionth total solar eclipse.)  Because it upends something about our sense of the world and its underlying orderliness?  Because we somehow find the crossing of the heavenly bodies intrinsically aesthetic?

Because we can see it?  No one much seems to care when various planets line up in what are supposed to be astrologically meaningful ways.  Or maybe because the event is dangerous and capable of damaging our eyes.

Or is it like a football game, namely that you go someplace to watch it and drink a lot of beer?  Would it be a lesser public event if everyone could see it perfectly from their back yard?  Few people get to see it from a plane.

I expect to be underwhelmed.

I will be doing a Conversation with Tyler with her.  On the off chance you don’t already know, here is a brief Wikipedia summary of her work:

Mary Roach is an American author, specializing in popular science and humor.[1] As of 2016, she has published seven books,: Stiff: The Curious Lives of Human Cadavers (2003), Spook: Science Tackles the Afterlife (2005) (published in some markets as Six Feet Over: Adventures in the Afterlife), Bonk: The Curious Coupling of Science and Sex (2008), Packing for Mars: The Curious Science of Life in the Void (2010), My Planet: Finding Humor in the Oddest Places, Gulp: Adventures on the Alimentary Canal (2013), and Grunt: The Curious Science of Humans at War (2016).

But there is much more to her than that.  Here is the full Wikipedia page.  Here is her own home page.

So what should I ask?  I thank you in advance for your inspiration.

Where to even begin enumerating the wealth of fruitful work — some of it highly critical — that continues to emerge from real engagement with Freud’s ideas? Consider Marina Warner’s musings on Freud’s mediation of Eastern and Western cultural tropes told through the story of his Oriental carpet-draped couch; Rubén Gallo’s panoramic exploration of the reception of Freud’s work in Mexico and the reciprocal influence of Mexican culture on Freud; and the rich medley of sociopolitical critiques grounded in Lacan’s reinterpretation of Freud’s thought.

The idea that large parts of our mental life remain obscure or even entirely mysterious to us; that we benefit from attending to the influence of these depths upon our surface selves, our behaviors, language, dreams and fantasies; that we can sometimes be consumed by our childhood familial roles and even find ourselves re-enacting them as adults; that our sexuality might be as ambiguous and multifaceted as our compendious emotional beings and individual histories — these core conceits, in the forms they circulate among us, are indebted to Freud’s writings. Now that we’ve effectively expelled Freud from the therapeutic clinic, have we become less neurotic? With that baneful “illusion” gone, and with all our psychopharmaceuticals and empirically grounded cognitive therapy techniques firmly in place, can we assert that we’ve advanced toward some more rational state of mental health than that enjoyed by our forebears in the heyday of analysis? Indeed, with a commander in chief who often seems to act entirely out of the depths of a dark unconscious, we might all do better to read more, not less, of Freud.

That is from an excellent NYT book review by George Prochnik.