Month: July 2021

Scientists discover spiders are eating snakes all over the world

“They can outfight snakes 10 to 30 times their size,” says the University of Basel in Switzerland.

According to a new meta-analysis study, perhaps snakes should be fearful of spiders. It seems arachnids like to chow down on the reptiles, all over the world.

The study, published in The Journal of Arachnology, has the straightforward title Spiders (Arachnida: Araneae) Feeding on Snakes (Reptilia: Squamata). The researchers looked at 319 reports of spiders feeding on snakes from every continent except Antarctica. Most of the events occurred in the US and Australia.

The data showed that spiders representing 11 different families have been observed eating snakes. “That so many different groups of spiders sometimes eat snakes is a completely novel finding,” lead author and arachnologist Martin Nyffeler said in a Monday news release from Switzerland’s University of Basel. Guess we can add the discovery to our Surprising Insect Dining Habits file, alongside praying mantises eating hummingbird brains.

Here is the full story, via Shaffin.

Tuesday assorted links

1. Taiwan and TSMC dependence.

2. Claims about necks.

3. Replicable mask results.

4. Rigged for thee but not for me?

5. Can individual investors beat the market?

6. “With low level of infections, vaccines may (depending on testing strategy, but especially with universal or random testing) appear ineffective simply because of randomness due to false positives that would constitute most of the positive outcomes” Link here.

Use Fractional Dosing to Speed Vaccination and Save Lives

I’ve been shouting about fractional dosing since January, most recently with my post A Half Dose of Moderna is More Effective Than a Full Dose of AstraZeneca and the associated paper with Michael Kremer and co-authors. Yesterday we saw some big movement. Writing in Nature Medicine, WHO epidemiologists Benjamin Cowling and Wey Wen Lim and evolutionary biologist Sarah Cobey title a correspondence:

Fractionation of COVID-19 vaccine doses could extend limited supplies and reduce mortality.

Exactly so. They write:

Dose-finding studies indicate that fractional doses of mRNA vaccines could still elicit a robust immune response to COVID-192,3. In a non-randomized open-label phase 1/2 trial of the BNT162b2 vaccine, doses as low as one third (10 μg) of the full dose produced antibody and cellular immune responses comparable to those achieved with the full dose of 30 μg (ref. 4). Specifically, the geometric mean titer of neutralizing antibodies 21 days after the second vaccine dose was 166 for the group that received 10 μg, almost the same as the geometric mean titer of 161 for the group that received 30 μg, and 63 days after the second dose, these titers were 181 and 133, respectively4. For the mRNA-1273 vaccine, a dose of 25 μg conferred geometric mean PRNT80 titers (the inverse of the concentration of serum needed to reduce the number of plaques by 80% in a plaque reduction neutralization test) of 340 at 14 days after the second dose, compared with a value of 654 for the group that received the standard dose of 100 μg (ref. 5). According to the model proposed by Khoury et al.6, if vaccine efficacy at the full dose is 95%, a reduction in dose that led to as much as a halving in the post-vaccination geometric mean titer could still be in the range of 85–90%. Although other components of the immune response may also contribute to efficacy, these dose-finding data are at least indicative of the potential for further exploration of fractionation as a dose-sparing strategy. Durability of responses after fractional doses should also be explored.

…Concerns about the evolution of vaccine resistance have been posited as a potential drawback of dose-sparing strategies. However, vaccines that provide protection against clinical disease seem to also reduce transmission, which indicates that expanding partial vaccination coverage could reduce the incidence of infection. As described in a recent paper, lower prevalence should slow, not accelerate, the emergence and spread of new SARS-CoV-2 variants8.

…In conclusion, fractionated doses could provide a feasible solution that extends limited supplies of vaccines against COVID-19, which is a major challenge for low- and middle-income countries.

Also a new paper in preprint just showed that 1/4 doses of Moderna create a substantial and lasting immune response on par with that from natural infection.

Here we examined vaccine-specific CD4+ T cell, CD8+ T cell, binding antibody, and neutralizing antibody responses to the 25 ug Moderna mRNA-1273 vaccine over 7 months post-immunization, including multiple age groups, with a particular interest in assessing whether pre-existing crossreactive T cell memory impacts vaccine-generated immunity. Low dose (25 ug) mRNA-1273 elicited durable Spike binding antibodies comparable to that of convalescent COVID-19 cases. Vaccine-generated Spike memory CD4+ T cells 6 months post-boost were comparable in quantity and quality to COVID-19 cases, including the presence of TFH cells and IFNg-expressing cells.

Finally, an article in Reuters notes that Moderna are preparing to launch a 50 ug dose regimen as a booster and for children. Thus, contrary to some critics of our paper, the technology is ready.

Frankly, governments are way behind on this–they should have been pushing the vaccine manufacturers and funding trials on alternative dosing since at least January. Indeed, imagine how many lives we might have saved had we listened to Operation Warp Speed advisor Moncef Slaoui who advocated for half doses in January. On a world scale, we could have vaccinated tens even hundreds of millions more people by now had we ramped up fractional dosing.

At this point, it’s my view that there is enough knowledge to justify rolling out alternative dosing in any hot spot or in any country worried about outbreaks. Roll it out in a randomized fashion (as Kominers and I discussed in the context of the US vaccination rollout) to study it in real time but start the roll out now. Lives can be saved if we speed up vaccination, especially of the best vaccines we have, the mRNAs. Moderna and Pfizer have together pledged to deliver (mostly Pfizer and mostly through the US) some 250m vaccine doses to COVAX in 2021 for delivery to less developed countries. If we go to half-doses that becomes 500m doses–a life saver. And recall these points made earlier:

Judging by neutralizing antibodies, a 50 ug dose of, for example, Moderna looks to be more effective than standard dosing of many other vaccines including AZ and J&J and much better than others such as Sinovac. Thus alternative dosing is a way to *increase* the quality of vaccine for many people.

A 50 ug dose vaccine available today is much higher quality than a 100 ug dose vaccine available one year from now.

If we have the will, we can increase vaccine supply very rapidly.

The Public Choice Outreach Conference!

The Public Choice Outreach Conference, a compact lecture series designed as a “crash course” in Public Choice for students planning careers in academia, journalism, law, or public policy, will be online this year–a week of noon to 1:15 (EST) Zooms, August 2-7.

Monday, August 2
An Introduction to Public Choice—Alex Tabarrok

Tuesday, August 3
Arrow’s Theorem and All That—Alex Tabarrok

Wednesday, August 4
Public Choice and Development Economics—Shruti Rajagopalan

Thursday, August 5
Evaluating Democratic Institutions—Garett Jones

Friday, August 6
Futarchy: An Alternative Decision-Making Procedure—Robin Hanson

Saturday, August 7
Hayek and Buchanan—Peter Boettke

You can find out more here and the application is here. The program is designed for students but going online will allow us to expand the attendees so do apply!

Abolishing tenure is the least of my proposals

In my latest Bloomberg column I attempt to design an ideal university from scratch.  The point is not that all schools should be this way, rather this is the experiment I would like to see at the margin:

I would start with what I expect students to know. They should be able to write very well, have  a basic understanding of economics and public policy, and a decent working knowledge of statistical reasoning. I would give a degree to students who demonstrated “B-grade” competence in all of these areas; what now goes for passing C-minus work wouldn’t cut it.

Most important, the people who write and grade the students’ tests would not be their instructors. So students would have to acquire a genuine general knowledge base, not just memorize what is supposed to be on the exam.

Next, each student would have the equivalent of a GitHub certification page. If you learned three programming languages, for example, or won a prize in a science fair, that would go on your page as a credential. But it would not count as a credit toward graduation. Some students could finish their degrees in a year or two even if their pages were not adorned with many accomplishments, while others might fill their pages but get no degree.

My imaginary school would not have many assistant deans, student affairs staff or sports teams. The focus would be on paying more money to the better instructors.


Instructors would not have tenure, but would have to compete for students — by offering them classes and services that would help them graduate and improve the quality of their certification pages. Teachers would be compensated on the basis of how many students they could attract, in a manner suggested long ago by Adam Smith, who himself lived under such a system in 18th-century Scotland.

The very best instructors could earn $300,000 to $400,000 a year…

The school would hire online instructors too, many of them from poorer countries and working at lower wages. So you might take French from a tutor in Senegal, or have a high school teacher from Tamil Nadu read your essays and offer writing tips. I am a big believer in face-to-face instruction, but in my school it would have to compete with online instruction. For this reason, I think my school would have a much more diverse faculty and instructional base than any other institution of higher education. None of the instructors would be required to have any undergraduate or advanced degrees.

The goal is to introduce competition across as many different margins as possible.  There would be an “all on-line” option as well, offered to anyone in the world, though of course the on-line degree might be worth less as judged in the market place.

One issue I did not have time to get into is how the school would “shadow price” its different services to students.  Access to different services has to be priced somehow, so should the school hand out total vouchers to each student for use within the school?  Should the on-line and also face-to-face classes be priced at marginal cost (plus mark-up)?  Or do positive externalities from class cohesion mean that the face-to-face classes should be priced at some additional discount?  To what extent should factors other than this shadow price system be used to allocate access to classes?

Wyoming fact of the day

Wyoming—the first US state to grant a charter to a crypto bank—has approved legal status for a decentralized autonomous organization (DAO), the American CryptoFed DAO, according to an announcement on Sunday. The organization, which has a mission to introduce a new monetary system, now becomes the first legally recognized DAO in the U.S.

It comes after Wyoming lawmakers voted in March to pass a bill allowing DAOs to be officially registered in the state. The law affords these entities—which are governed by smart contracts and dispense with the hierarchical control structure seen in traditional companies—the same rights as a limited liability company. The bill came into effect on July 1, 2021.

Just think — limited liability for “a company managed by nobody”!  And:

The DAO law also solidifies Wyoming’s reputation as the most crypto-friendly U.S. state. Last year, it was the first in the US to issue a state charter for crypto banks and has already licensed two: Kraken and Avanti.

Here is the full story, via Shaffin Shariff.

Which media have proven sticky as pandemic has diminished?

The single biggest new media habit to be formed during the pandemic appears to be gaming. The extra hour per week that people spent gaming last year represented the largest percentage increase of any media category. And unlike other lockdown hobbies, it is showing no sign of falling away as life gets back to normal. It has become “a sticky habit”, says Craig Chapple of Sensor Tower. He finds that last year people installed 56.2bn gaming apps, a third more than in 2019 (and three times the rate of increase the previous year). The easing of lockdowns is not denting the habit: the first quarter of 2021 saw more installations than any quarter of 2020. Roblox, a sprawling platform on which people make and share their own basic games, reported that in the first quarter of this year players spent nearly 10bn hours on the platform, nearly twice as much time as they spent in the same period in 2020.


…whereas all other generations of Americans named television and films as their favourite form of home entertainment, Generation Z ranked them last, after video games, music, web browsing and social media.

Here is more from The Economist.

A new study of crypto ownership

Employing representative data from the U.S. Survey of Consumer Payment Choice, we disprove the hypothesis that cryptocurrency investors are motivated by distrust in fiat currencies or regulated finance. Compared with the general population, investors show no differences in their level of security concerns with either cash or commercial banking services. We find that cryptocurrency investors tend to be educated, young and digital natives. In recent years, a gap in ownership of cryptocurrencies across genders has emerged. We examine how investor characteristics vary across cryptocurrencies and show that owners of cryptocurrencies increasingly tend to hold their investment for longer periods.


Moving from a lower category of education to a higher one increases the probability, on average, of recognising at least one cryptocurrency by around 8.7 to 11.1 percentage points…Being a man in the US increases, on average, the probability of knowing
about at least one cryptocurrency by between 9.6 and 12.1 percentage points.

That is from a recent paper by Raphael Auer and David Tercero-Lucas, via Shaffin Shariff.  Data are from 2019.

Facts and uncertainties about ear wax

Our attitude to ear wax is in some ways surprising. A review of impacted ear wax estimates that 2.3 million people a year in the United Kingdom suffer problems with wax needing treatment, with some 4 million ears being syringed annually.2 This makes it possibly the the most common therapeutic procedure carried out on any part of the body. Symptoms of excessive wax or impaction, especially in the elderly, include not only hearing loss but tinnitus, dizziness, infections, social withdrawal, poor work function and mild paranoia. Other problems include general disorientation and loss of an aural sense of direction. With unilateral wax, sounds can appear to be coming from the wrong side, leading to accidents as a driver or especially as a pedestrian. Inappropriate self-treatment (or even treatment by health professionals) can cause perforated eardrums and in very rare cases cochlear damage, leading to nystagmus and sensorineural deafness. In spite of this catalogue of harms, the clinical profile and management of excessive wax are poorly understood. The evidence base is poor and inconsistent, leading to few strong recommendations, even relating to the most commonly used treatments.

Low esteem for ear wax is surprising in other ways too. As a substance, it is unique in the human and mammalian body. This is due to its position in our sole anatomical cul-de-sac. Everywhere else on our body surface, dead and redundant skin cells fall off or are scrubbed away when we wash. In the ear canal – which points forwards and downwards and might otherwise turn into a dermatological garbage dump – ear wax binds these together, along with other assorted detritus that may have entered from the world outside. It is then moved up to the exit by jaw movements and as a result of the skin of the canal slowly moving outwards like an escalator. Wax also prevents multiplication of micro-organisms and infection. It is as essential as sweat and tears, although perhaps not quite as vital as blood. Wax is also fascinating in its own right.

Imagine an ear wax post that is not solely about Q-tips! (Have you ever wondered why they have to be so dangerous?  Can’t you just put them in a little way?  Or is there some indivisibility here?  I have never understood the anguished warnings here.  If you are not using Q-tips at all, you only have to put them in a little way to pull out a lot of earwax, right?  Solve for the equilibrium!)

Here is more by John Launer, about ear wax throughout, via Michelle Dawson.

Sunday assorted links

1. Culture wars are long wars.  And is it the Left that has jacked up the culture wars?

2. More Scott Sumner movie reviews, he is always right.

3. Cleaner air has contributed one-fifth of U.S. maize and soybean yield gains since 1999.

4. Do we enjoy our stereotypes?

5. Police officer plays Taylor Swift song to try to block video.

6. “Demisexual people only feel sexually attracted to someone when they have an emotional bond…

Nematodes Maximize Expected Utility on the heels of the new paper showing that the trading behavior of mycorrhizal fungi is consistent with the predictions of general equilibrium theory we have that nematodes obey the generalized axiom of revealed preference. It would be amusing if economics turns out to work well everywhere except for humans.

Abstract: In value-based decision making, options are selected according to subjective values assigned by the individual to available goods and actions. Despite the importance of this faculty of the mind, the neural mechanisms of value assignments, and how choices are directed by them, remain obscure. To investigate this problem, we used a classic measure of utility maximization, the Generalized Axiom of Revealed Preference, to quantify internal consistency of food preferences in Caenorhabditis elegans, a nematode worm with a nervous system of only 302 neurons. Using a novel combination of microfluidics and electro-physiology, we found that C. elegans food choices fulfill the necessary and sufficient conditions for utility maximization, indicating that nematodes behave exactly as if they maintain, and attempt to maximize, an underlying representation of subjective value. Food choices are well-fit by a utility function widely used to model human consumers. Moreover, as in many other animals, subjective values in C. elegans are learned, a process we now find requires intact dopamine signaling. Differential responses of identified chemosensory neurons to foods with distinct growth potential are amplified by prior consumption of these foods, suggesting that these neurons may be part of a value-assignment system. The demonstration of utility maximization in an organism with no more than several hundred neurons sets a new lower bound on the computational requirements for maximization, and offers the prospect of an essentially complete explanation of value-based decision making at single neuron resolution.

Photo Credit: By Agricultural Research Service – source (15016 KB); Description page, Public Domain,

Hat tip: Derek Lowe.

Some major cities ranked by surveillance cameras per km

Not what I would have expected:

1. Seoul

2. Paris

3. Boston

4. NYC

5. Baltimore

6. San Francisco

7. Tokyo

8. London

9. Chicago

10. Philadelphia

11. Bangkok

12. Washington, D.C.

13. Milwaukee

14. Singapore

15. Seattle

16. Los Angeles

The difference here between Seoul and Los Angeles is almost 4x.  Mostly I am surprised that London and also Singapore are so low.  Here is the paper, via the excellent Samir Varma.

*The Volga: A History of Russia’s Greatest River*

The author is Janet M. Hartley from LSE, here is one excerpt:

…the religious composition on the Volga is complex.  Finno-Ugric settlers originally followed shamanistic beliefs, although many converted, at least nominally, to Orthodoxy after they became subjects of the Russian Empire.  The ruler and the elite in Khazaria probably converted to Judaism sometime in the early ninth century.  Kalmyks in the south and south-east of the Volga were Buddhists (the only Buddhists in Europe).  The Bolgar state, the Golden Horse and the khanates of Kazan and Astrakhan were, or became, Muslim.  the Russian and Soviet states were conscious of the potential threat of Islam in the Volga region from the time of the conquest of Kazan in 1552.  The history of the Volga is, in part, the history of (often forced) conversion to Orthodoxy by the Russian government and the reaction to this of the local inhabitants.  In many cases, the conversion process was incomplete or, in the case of Islam, could be reversed.  The remoteness of much of the Volga countryside attracted Old Believers — that is, schismatics from the Russian Orthodox Church who did not accept the changes in liturgy and practice in the middle of the seventeenth century.