The authors are Alex Bell, Raj Chetty, Xavier Jaravel, Neviana Petkova, and John Van Reenen, here is the abstract:

We characterize the factors that determine who becomes an inventor in America by using deidentified data on 1.2 million inventors from patent records linked to tax records. We establish three sets of results. First, children from high-income (top 1%) families are ten times as likely to become inventors as those from below-median income families. There are similarly large gaps by race and gender. Differences in innate ability, as measured by test scores in early childhood, explain relatively little of these gaps. Second, exposure to innovation during childhood has significant causal effects on children’s propensities to become inventors. Growing up in a neighborhood or family with a high innovation rate in a specific technology class leads to a higher probability of patenting in exactly the same technology class. These exposure effects are gender-specific: girls are more likely to become inventors in a particular technology class if they grow up in an area with more female inventors in that technology class. Third, the financial returns to inventions are extremely skewed and highly correlated with their scientific impact, as measured by citations. Consistent with the importance of exposure effects and contrary to standard models of career selection, women and disadvantaged youth are as under-represented among high-impact inventors as they are among inventors as a whole. We develop a simple model of inventors’ careers that matches these empirical results. The model implies that increasing exposure to innovation in childhood may have larger impacts on innovation than increasing the financial incentives to innovate, for instance by cutting tax rates. In particular, there are many “lost Einsteins” – individuals who would have had highly impactful inventions had they been exposed to innovation.

Here is the paper, here are the slides (best place to start), here is a David Leonhardt column on it.

Florence!  Motown!  Kuna molas!  David Hume knew this!  The work looks very interesting, though I doubt if the main effect is actually channeled through absolute income, as evidenced by the immediately afore-mentioned examples.  Also, I don’t think their tax analysis quite holds up once you see intermediaries as needing to cover fixed costs for the innovators.  Taxing profits from innovation then lowers the number of potential innovators quite a bit, by discouraging investment from the intermediaries.

That is the new and excellent history by Leslie Berlin, substantive throughout, here is one good bit of many:

In March 1967, Robert and Taylor, jointly leading a meeting of ARPA’s principal investigators in Ann Arbor, Michigan, told the researchers that ARPA was going to build a computer network and they were all expected to connect to it.  The principle investigators were not enthusiastic.  They were busy running their labs and doing their own work.  They saw no real reason to add this network to their responsibilities.  Researchers with more powerful computers worried that those with less computing power would use the network to commandeer precious computing cycles.  “If I could not get some ARPA-funded participants involved in a commitment to a purpose higher than “Who is going to steal the next ten percent of my memory cycles?”, there would be no network,” Taylor later wrote.  Roberts agreed: “They wanted to buy their own machines and hide in the corner.”

You can buy the book here, here is one good review from Wired, excerpt:

While piecing together a timeline of the Valley’s early history—picture end-to-end sheets of paper covered in black dots—Berlin was amazed to discover a period of rapid-fire innovation between 1969 and 1976 that included the first Arpanet transmission; the birth of videogames; and the launch of Apple, Atari, Genentech, and major venture firms such as Kleiner Perkins and Sequoia Capital. “I just thought, ‘What the heck was going on in those years?’ ” she says.

Here is praise from Patrick Collison on Twitter.

From a recent survey by Pennington, Heim, Levy, and Larkin:

This systematic literature review appraises critically the mediating variables of stereotype threat. A bibliographic search was conducted across electronic databases between 1995 and 2015. The search identified 45 experiments from 38 articles and 17 unique proposed mediators that were categorized into affective/subjective (n = 6), cognitive (n = 7) and motivational mechanisms (n = 4). Empirical support was accrued for mediators such as anxiety, negative thinking, and mind-wandering, which are suggested to co-opt working memory resources under stereotype threat. Other research points to the assertion that stereotype threatened individuals may be motivated to disconfirm negative stereotypes, which can have a paradoxical effect of hampering performance. However, stereotype threat appears to affect diverse social groups in different ways, with no one mediator providing unequivocal empirical support. Underpinned by the multi-threat framework, the discussion postulates that different forms of stereotype threat may be mediated by distinct mechanisms.

Or from Wikipedia:

Whether the effect occurs at all has also been questioned, with researchers failing to replicate the finding. Flore and Wicherts concluded the reported effect is small, but also that the field is inflated by publication bias. They argue that, correcting for this, the most likely true effect size is near zero (see meta-analytic plot, highlighting both the restriction of large effect to low-powered studies, and the plot asymmetry which occurs when publication bias is active).[

Earlier meta-analyses reached similar conclusions. For instance, Ganley et al. (2013)[10] examined stereotype threat on mathematics test performance. They report a series of 3 studies, with a total sample of 931 students. These included both childhood and adolescent subjects and three activation methods, ranging from implicit to explicit. While they found some evidence of gender differences in math, these occurred regardless of stereotype threat. Importantly, they found “no evidence that the mathematics performance of school-age girls was impacted by stereotype threat”. In addition, they report that evidence for stereotype threat in children appears to be subject to publication bias. The literature may reflect selective publication of false-positive effects in underpowered studies, where large, well-controlled studies find smaller or non-significant effects:

Personally, I find stereotype threat to be a very intuitive idea with a fair amount of anecdotal support.  So why aren’t these meta-results more convincing?

A remarkable new paper on logical induction by Scott Garrabrant, Tsvi Benson-Tilsen, Andrew Critch, Nate Soares, and Jessica Taylor dramatically extends Ramsey’s Dutch book arguments in support of Bayesian epistemology and in so doing demonstrates deep connections between logical thinking and efficient markets. The research was supported by the Machine Intelligence Research Institute.

We present a computable algorithm that assigns probabilities to every logical statement in a given formal language, and refines those probabilities over time. For instance, if the language is Peano arithmetic, it assigns probabilities to all arithmetical statements, including claims about the twin prime conjecture, the outputs of long-running computations, and its own probabilities. We show that our algorithm, an instance of what we call a logical inductor, satisfies a number of intuitive desiderata, including: (1) it learns to predict patterns
of truth and falsehood in logical statements, often long before having the resources to evaluate the statements, so long as the patterns can be written down in polynomial time; (2) it learns to use appropriate statistical summaries to predict sequences of statements whose truth values appear pseudorandom; and (3) it learns to have accurate beliefs about its own current beliefs, in a manner that avoids the standard paradoxes of self-reference. For example, if a given computer program only ever produces outputs in a certain range, a logical inductor learns this fact in a timely manner; and if late digits in the decimal expansion of π are difficult to predict, then a logical inductor learns to assign ≈ 10% probability to “the nth digit of π is a 7” for large n. Logical inductors also learn to trust their future beliefs more than their current beliefs, and their beliefs are coherent in the limit (whenever φ → ψ, P∞(φ) ≤ P∞(ψ), and so on); and logical inductors strictly dominate the universal semimeasure in the limit.

These properties and many others all follow from a single logical induction criterion, which is motivated by a series of stock trading analogies. Roughly speaking, each logical sentence φ is associated with a stock that is worth $1 per share if φ is true and nothing otherwise, and we interpret the belief-state of a logically uncertain reasoner as a set of market prices, where Pn(φ) = 50% means that on day n, shares of φ may be bought or sold from the reasoner for 50¢. The logical induction criterion says (very roughly) that there should not be any polynomial-time computable trading strategy with finite risk tolerance that earns unbounded profits in that market over time. This criterion bears strong resemblance to the “no Dutch book” criteria that support both expected utility theory (von Neumann and Morgenstern 1944) and Bayesian probability theory (Ramsey 1931; de Finetti 1937).

The authors are quick to acknowledge that their algorithm holds only in the limit which makes it impractical to implement. Nevertheless, the first fully rational beings on the planet will surely be artificial intelligences.

In 2013, the Post-Polio Health International (PPHI) organizations estimated that there were six to eight iron lung users in the United States. Now, PPHI executive director Brian Tiburzi says he doesn’t know anyone alive still using the negative-pressure ventilators. This fall, I met three polio survivors who depend on iron lungs. They are among the last few, possibly the last three.”

…In the 1940s and 1950s, hospitals across the country were filled with rows of iron lungs that kept victims alive. Lillard recalls being in rooms packed with metal tubes—especially when there were storms and all the men, women, adults, and children would be moved to the same room so nurses could manually operate the iron lungs if the power went out. “The period of time that it took the nurse to get out of the chair, it seemed like forever because you weren’t breathing,” Lillard said. “You just laid there and you could feel your heart beating and it was just terrifying. The only noise that you can make when you can’t breathe is clicking your tongue. And that whole dark room just sounded like a big room full of chickens just cluck-cluck-clucking. All the nurses were saying, ‘Just a second, you’ll be breathing in just a second.’”

…Mia Farrow only had to spend eight months in an iron lung when she was nine, before going on to become a famous actress and polio advocate.

Here is the full story, via the excellent Samir Varma.

*The Wizard and the Prophet*

by on November 9, 2017 at 1:34 pm in Books, History, Science | Permalink

That is the new Charles C. Mann book, I pre-ordered long ago, here is the new Kirkus review:

A dual biography of two significant figures who “had little regard” for each other’s work but “were largely responsible for the creation of the basic intellectual blueprints that institutions around the world use today for understanding our environmental dilemmas.”

A thick book featuring two scientists unknown to most readers is a tough sell, but bestselling journalist and historian Mann (1493: Uncovering the New World Columbus Created, 2011, etc.), a correspondent for the Atlantic, Science, and Wired, turns in his usual masterful performance. Nobel Prize–winning agronomist Norman Borlaug (1914-2009) developed high-yield wheat varieties and championed agricultural techniques that led to the “Green Revolution,” vastly increasing world food production. Ornithologist William Vogt (1902-1968) studied the relationship between resources and population and wrote the 1948 bestseller Road to Survival, a founding document of modern environmentalism in which the author maintains that current trends will lead to overpopulation and mass hunger. Borlaug and Vogt represent two sides of a centurylong dispute between what Mann calls “wizards,” who believe that science will allow humans to continue prospering, and “prophets,” who predict disaster unless we accept that our planet’s resources are limited. Beginning with admiring biographies, the author moves on to the environmental challenges the two men symbolize. Agriculture will require a second green revolution by 2050 to feed an estimated 10 billion inhabitants. Only 1 percent of Earth’s water is fresh and accessible; three-quarters goes to agriculture, and shortages are already alarming. More than 1.2 billion people still lack electricity; whether to produce more or use less energy bitterly divides both sides. Neither denies that human activities are wreaking havoc with Earth’s climate. Mann’s most spectacular accomplishment is to take no sides. Readers will thrill to the wizards’ astounding advances and believe the prophets’ gloomy forecasts, and they will also discover that technological miracles produce nasty side effects and that self-sacrifice, as prophets urge, has proven contrary to human nature.

An insightful, highly significant account that makes no predictions but lays out the critical environmental problems already upon us.

You can pre-order here.

There is a new NBER working paper on these topics, by Anna Chorniy, Janet Currie, and Lyudmyla Sonchak, here is the abstract:

In the U.S., nearly 11% of school-age children have been diagnosed with ADHD, and approximately 10% of children suffer from asthma. In the last decade, the number of children diagnosed with these conditions has inexplicably been on the rise. This paper proposes a novel explanation of this trend. First, the increase is concentrated in the Medicaid caseload nationwide. Second, nearly 80% of states transitioned their Medicaid programs from fee-for-service (FFS) reimbursement to managed care (MMC) by 2016. Using Medicaid claims from South Carolina, we show that this change contributed to the increase in asthma and ADHD caseloads. Empirically, we rely on exogenous variation in MMC enrollment due a change in the “default” Medicaid plan from FFS or MMC, and an increase in the availability of MMC. We find that the transition from FFS to MMC explains most of the rise in the number of Medicaid children being treated for ADHD and asthma. These results can be explained by the incentives created by the risk adjustment and quality control systems in MMC.

The economics of medical diagnoses remain a drastically understudied area.

I will be having a Conversations with Tyler with Andy Weir, author of The Martian and assorted on-line works (many of which appear to be off-line at the moment).  He has a new book coming out, Artemis.  Here is Andy’s Wikipedia page.

I thank you all in advance for your ideas and assistance.

Lights On, Lights Off

by on October 29, 2017 at 7:21 am in Economics, Science | Permalink

You can learn a lot from satellite pictures of the earth at night; the famous picture of North and South Korea, which Tyler and I feature in Modern Principles, is just one such example.

ESRI has an interesting picture-story illustrating the lights that have turned on and those that have turned off between 2012 and 2016. It’s remarkable how much North India literally turns on in this short space of time. Lights have also turned off around the globe. Not only in places like Syria but also in much of the United States and Northern Europe. In the latter two cases, as the surprising result of more efficient lighting and campaigns to reduce light pollution. Check it out.

After decades of researching the impact that humans are having on animal and plant species around the world, Chris Thomas has a simple message: Cheer up. Yes, we’ve wiped out woolly mammoths and ground sloths, and are finishing off black rhinos and Siberian tigers, but the doom is not all gloom. Myriad species, thanks in large part to humans who inadvertently transport them around the world, have blossomed in new regions, mated with like species and formed new hybrids that have themselves gone forth and prospered. We’re talking mammals, birds, trees, insects, microbes—all your flora and fauna. “Virtually all countries and islands in the world have experienced substantial increases in the numbers of species that can be found in and on them,” writes Thomas in his new book, Inheritors of the Earth: How Nature Is Thriving in an Age of Extinction.

That is the introduction to a very interesting interview with Chris Thomas, a conservation biologist. Read the whole thing.

Hat tip: The Browser.

The great Tim Urban of Wait but Why has a deep dive into Why Cryonics Makes Sense.

A key argument:

Here’s an interesting way to think about it: Imagine a patient arriving in an ambulance to Hospital A, a typical modern hospital. The patient’s heart stopped 15 minutes before the EMTs arrived and he is immediately pronounced dead at the hospital. What if, though, the doctors at Hospital A learned that Hospital B across the street had developed a radical new technology that could revive a patient anytime within 60 minutes after cardiac arrest with no long-term damage? What would the people at Hospital A do?

Of course, they would rush the patient across the street to Hospital B to save him. If Hospital B did save the patient, then by definition the patient wouldn’t actually have been dead in Hospital A, just pronounced deadbecause Hospital A viewed him as entirely and without exception doomed.

What cryonicists suggest is that in many cases where today a patient is pronounced dead, they’re not dead but rather doomed, and that there is a Hospital B that can save the day—but instead of being in a different place, it’s in a different time. It’s in the future.

Kurzgesagt and CGP Grey also have a new two part video series on why we should stop aging forever. The first one is below. The second is here.

Am I seeing a trend? I hope so. To quote CGP Grey:

Humans must discard the learned helplessness that the reaper and their own brains have imposed on them.

*The Fate of Rome*

by on October 19, 2017 at 11:21 am in Books, History, Medicine, Science, Uncategorized | Permalink

That is the new and very important book by Kyle Harper, with the subtitle Climate, Disease, & the End of an Empire.  I am just reading through this now, but it appears to be an significant revision of our views on the decline of Rome.  p.21 offers a capsule summary, which I will summarize in turn:

1. During the reign of Marcus Aurelius, a pandemic “interrupted the economic and demographic expansion” of the empire.

2. In the middle of the third century, a mix of drought, pestilence, and political challenge “led to the sudden disintegration of the empire.”  The empire however was willfully rebuilt, with a new emperor, new system of government, and in due time a new religion.

3. The coherence of this new empire was broken in the late fourth and early fifth centuries.  “The entire weight of the Eurasian steppe seemed to lean, in new and unsustainable ways, against the edifice of Roman power…and…the western half of the empire buckled.”

4. In the east there was a resurgent Roman Empire, but this was “violently halted by one of the worst environmental catastrophes in recorded history — the double blow of bubonic plague and a little ice age.”

Here is a key passage from the book:

The centuries of later Roman history might be considered the age of pandemic disease.  Three times the empire was rocked by mortality events with stunning geographical reach.  In AD 165 an event known as the Antonine Plague, probably caused by smallpox, erupted.  In AD 249, an uncertain pathogen swept the territories of Roman rule.  And in AD 541, the first great pandemic of Yersinia pestis, the agent that causes bubonic plague, arrived and lingered for over two hundreds years.  the magnitude of these biological catastrophes is almost incomprehensible.

Here is the book on Amazon.  Here is Kyle Harper on Twitter.  Here is Harper on; he is also Provost at the University of Oklahoma.

I do not feel I can assess the veracity of this thesis, but it does seem to be intelligently and reasonably argued.

Here is the transcript and podcast, here is the summary introduction:

She joins Tyler for a conversation covering the full range of her curiosity, including fear, acclimating to grossness, chatting with the dead, freezing one’s head, why bedpans can kill you, sex robots, Freud, thinking like an astronaut, the proper way to eat a fry, and why there’s a Medicare reimbursement code for maggots.

Here are a few excerpts:

ROACH: It is never uncomfortable. People sometimes say, “The questions that you ask people, is it an awkward interview? When you went to Avenal State Prison for the rectum chapter of Gulp, and you, talking to this convicted murderer about using his rectum to smuggle cellphones and other things, was that not a very awkward conversation to have?”

A little bit, but then you have to keep in mind, this is somebody for whom hooping, as it’s called, is . . . everybody does it. It’s just something that you do; it’s everyday to him. Like for a sex researcher, talking about orgasm is like talking about tire rotation for a car mechanic.


COWEN: To do a whirlwind tour of some of your books, you have a book on corpses. If you could chat with the dead, what would you ask them?

ROACH: Oh, if I could chat with the dead. Are we assuming the personality or the body?

COWEN: Well, both.

ROACH: The corpse?

COWEN: The corpse.

ROACH: Oh, is this a research corpse or . . .

COWEN: It’s a research corpse.

ROACH: …So what I’d say to the cadaver is, “Is this embarrassing for you? Are you OK with this? Are they treating you respectfully? Do you wish you had some clothes on?”


COWEN: Why do only 18 percent of people who are in the position to have a life-after-death experience actually have one? What’s your view on that?

ROACH: The trouble seems to be remembering the near-death experience.


COWEN: Why are bedpans dangerous?

There is much, much more at the link.  Jonathan Swift, Elvis, Adam Smith, and Jeff Sachs all make appearances, in addition to Catholicism, bee larvae, Mozambique, whether people know what they really want in sex, and whether it should be legal to harvest fresh road kill in Oregon.

From my email, by Jason N. Doctor:

You provide a good perspective on Blade Runner 2049.  In addition to the biblical references and themes, I was also impressed by the psychology and philosophy of mind references:

1)  After every event where he eliminates a replicant, “K” must take a cognitive interference test similar to those used most recently by Sendhil Mullianathan and Eldar Shafir to study the effects of economic scarcity on cognition–but to test if killing a replicant heightens his emotions by perhaps putting him in a moral quandary.

2) On the door to his apartment, some graffiti reads “F*** off Skinner”.  This seems odd in its prominence.  B.F. Skinner developed, to an extreme, John Watson’s radical suggestion that behavior does not have mental states. Skinner’s ideas shutout discussions of whether or not machines could support mental states. Of course, rational economics by similar methodologic scruple ignores mental states.

3)  The movie promotes the idea that there is no computation without representation.  Ana de Armis’ character formulates mental symbols in her relationship with K and behaves in accordance with interdefined internal states (we can’t predict some of her actions directly from stimuli). We are led to believe that she qualitatively experiences real love (though we cannot know) .  In irony, one of these mental symbols involves a longing to be a “real girl” by means that are unrelated to the mind-body problem.  She wants to being taken off the network, so that she can be in one place, just as are neurophysiologic organisms.

>All in all, the movie legitimizes the notion of (hardware agnostic) mental representations and takes a fairly hard stance in opposition to behaviorist constraints on psychological explanations. So it is a critique of behavioral psychology and indirectly rational economics.

I am not sure I trust any TFP measures (what if innovation is simply embodied in investment?), but this paper by Gerben Bakker, Nicholas Crafts, and Pieter Woltjer is worth a ponder:

We develop new aggregate and sectoral Total Factor Productivity (TFP) estimates for the United States between 1899 and 1941 through better coverage of sectors and better-measured labor quality, and find TFP-growth was lower than previously thought, broadly based across sectors, and strongly variant intertemporally. We then test and reject three prominent claims. First, the 1930s did not have the highest TFP-growth of the twentieth century. Second, TFP-growth was not predominantly caused by four ‘great inventions’. Third, TFP-growth was not driven indirectly by spillovers from great inventions such as electricity. Instead, the creative-destruction -friendly American innovation system was the main productivity driver.

For the pointer I thank David Levey.