Category: Uncategorized

A critique of contact-tracing apps

by  Tyler Cowen in

Here are some relevant criticisms from Soltani, Calo, and Bergstrom:

Studies suggest that people have on average about a dozen close contacts a day—incidents involving direct touch or a one-on-one conversation—yet even in the absence of social distancing measures the average infected person transmits to only 2 or 3 other people throughout the entire course of the disease. Fleeting interactions, such as crossing paths in the grocery store, will be substantially more common and substantially less likely to cause transmission. If the apps flag these lower-risk encounters as well, they will cast a wide net when reporting exposure. If they do not, they will miss a substantive fraction of transmission events. Because most exposures flagged by the apps will not lead to infection, many users will be instructed to self-quarantine even when they have not been infected. A person may put up with this once or twice, but after a few false alarms and the ensuing inconvenience of protracted self-isolation, we expect many will start to disregard the warnings.

And:

At least as problematic is the issue of false negatives—instances where these apps will fail to flag individuals as potentially at risk even when they’ve encountered someone with the virus. Smartphone penetration in the United States remains at about 81 percent—meaning that even if we had 100 percent installation of these apps (which is extremely unlikely without mandatory policies in place), we would still only see a fraction of the total exposure events (65 percent according to Metcalf’s Law). Furthermore, people don’t always have their phones on them.

And:

There is also a very real danger that these voluntary surveillance technologies will effectively become compulsory for any public and social engagement. Employers, retailers, or even policymakers can require that consumers display the results of their app before they are permitted to enter a grocery store, return back to work, or use public services—is as slowly becoming the norm in China, Hong Kong, and even being explored for visitors to Hawaii.

 

Taken with the false positive and “griefing” (intentionally crying wolf) issues outlined above, there is a real risk that these mobile-based apps can turn unaffected individuals into social pariahs, restricted from accessing public and private spaces or participating in social and economic activities. The likelihood that this will have a disparate impact on those already hardest hit by the pandemic is also high. Individuals living in densely populated neighborhoods and apartment buildings—characteristics that are also correlated to non-white and lower income communities—are likelier to experience incidences of false positives due their close proximity to one another.

In another study:

Nearly 3 in 5 Americans say they are either unable or unwilling to use the infection-alert system under development by Google and Apple, suggesting that it will be difficult to persuade enough people to use the app to make it effective against the coronavirus pandemic, a Washington Post–University of Maryland poll finds.

And here are skeptical remarks from Bruce Schneier.

I also have worried about how testing and liability law would interact.  If the positive cases test as positive, it may be harder for businesses and schools to reopen, because they did not “do enough” to keep the positive cases out, or perhaps the businesses and the schools are the ones doing the testing in the first place.  Whereas under a lower-testing “creative ambiguity” equilibrium, perhaps it is easier to think in terms of statistical rather than known lives lost, and to proceed with some generally beneficial activities, even though of course some positive cases will be walking through the doors.

I wonder if there also is a negative economic effect, over the longer haul, simply by making fear of the virus more focal in people’s minds.  The plus of course is simply that contact tracing does in fact slow down the spread of the virus and allows resources to be allocated to individuals and areas of greatest need.

Who wants to take UFO sightings more seriously?

by  Tyler Cowen in

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

Among my friends and acquaintances, the best predictor of how seriously they take the matter is whether they read science fiction in their youth. As you might expect, the science-fiction readers are willing to entertain the more outlandish possibilities. Even if these are not “little green men,” the idea that the Chinese or Russians have a craft that can track and outmaneuver the U.S. military is newsworthy in and of itself. So would be a secret U.S. craft, especially one unknown to military pilots.

The cynical view is that the science-fiction readers are a bit crazy and are trying to recapture the excitement of their youth by speculating about UFOs. Under this theory, they shouldn’t be taken any more seriously than Tolkien fans who wonder if orcs are hiding under the next stone.

The more positive view is that science-fiction readers are more willing to consider new ideas and practices. This kind of openness presumably is a good thing, at least in general, so why aren’t the opinions of more “open” observers accorded more respect? Science-fiction readers have long experience thinking about worlds that are very different from the current one, and perhaps that makes them more perceptive when something truly unusual does come along.

Some of the individuals who were early to see and point out Covid-19 risk, such as tech entrepreneur Balaji Srinivasan, also have taken the UFO reports seriously, perhaps due to the same flexibility of mind.

Do read the whole thing, the column does not excerpt easily.

Friday assorted links

by  Tyler Cowen

1. Black hole in the outer solar system?  By Edward Witten.

2. Mechanism design against cheaters.

3. “Except now it’s not my sister I want to vanquish, destroy and dominate—it’s my children.”

4. Homeostasis at R = 0?

5. Peruvian indigenous rap (NYT).

6. Paul Romer on tests and sodas.

7. The culture that was French: France to sell some of nation’s antique furniture to support hospitals.

8. The debate over Human Challenge Trials.

9. The culture that is Japan: should you video chat your local aquarium eel?

10. Madeline Kripke, doyenne of dictionaries, RIP.

Rapid progress from Fast Grants

by  Tyler Cowen in

I was pleased to read this NYT reporting:

Yet another team has been trying to find drugs that work against coronavirus — and also to learn why they work.

The team, led by Nevan Krogan at the University of California, San Francisco, has focused on how the new coronavirus takes over our cells at the molecular level.

The researchers determined that the virus manipulates our cells by locking onto at least 332 of our own proteins. By manipulating those proteins, the virus gets our cells to make new viruses.

Dr. Krogan’s team found 69 drugs that target the same proteins in our cells the virus does. They published the list in a preprint last month, suggesting that some might prove effective against Covid-19…

It turned out that most of the 69 candidates did fail. But both in Paris and New York [where the drugs were shipped for testing], the researchers found that nine drugs drove the virus down.

“The things we’re finding are 10 to a hundred times more potent than remdesivir,” Dr. Krogan said. He and his colleagues published their findings Thursday in the journal Nature.

The Krogan team was an early recipient of Fast Grants, and you will find more detail about their work at the above NYT link.  Fast Grants is also supporting Patrick Hsu and his team at UC Berkeley:

And the work of the Addgene team:

Nursing homes across nations

by  Tyler Cowen in

This is all from Michael A. Alcorn, from my email, no further indentation offered:

“Just to keep hammering on this nursing home point… I saw your Tweet about Eastern vs. Western Europe and decided to explore the nursing home angle there too. The WHO has data on the number of nursing and elderly home beds for different countries here. Unfortunately, the data only goes up to 2013-ish for many countries, but it’s suggestive nonetheless.

Italy and France were clearly trending up seven years ago in its number of beds… would be interesting to see if Italy had a similar jump to Spain at some point. The number of beds gives us a proxy for the number of people who are highly vulnerable to COVID-19. Obviously, these countries have different total populations, but I don’t think that should matter too much because I suspect nursing homes tend to be highly concentrated within countries (e.g., how many of France’s nursing homes are in the Paris metro?). Based on what I’ve read about nursing home staff often being low paid and so perhaps coming to work when sick and working at multiple facilities, I suspect nursing home density is nonlinearly related to the number of COVID-19 deaths in a country (especially when you account for some of the truly horrifying government decisions regarding nursing homes).

Here are those Nordic countries everyone likes to compare:

You can get exact numbers on the website, but Sweden had twice as many nursing home beds as Finland and three times as many as Norway. The ship might have sailed on what we can do to protect these vulnerable populations, but I would love to see a Fast Grant go towards investigating the COVID-19/nursing home tragedy.”

An epidemiologist (who is also an economist) responds

by  Tyler Cowen

Matthew Bonds, who is at Harvard, wrote this response to my original post on epidemiologists.  I am offering it in its entirety, click here.

Here is the first paragraph:

Since the novel coronavirus outbreak turned into a global health and economic crisis, one of the few silver linings has been unprecedented collaboration across spheres of science, innovation, and policy that have potential for long-term benefits. My training is in economics (PhD) and ecology (PhD) with a specialty in infectious disease modeling. Over the past decade, I have focused on implementing global health delivery programs where the lack of models and technical solutions are rarely the biggest problem – instead, the challenge often lies with breakdowns in the systems of delivering those solutions. That is not the case with COVID-19. We do not have solutions at our fingertips. We do not know the full scope of the problem, and consequently how to best navigate policy tradeoffs. So, I was dismayed to read, “What does this economist think of epidemiologists?” by Tyler Cowen, which struck me as a reinforcement (maybe even a celebration?) of boundaries that do more harm than good.

Do read the whole thing, and note that Bonds wrote his economics dissertation with Dwight Lee (a former co-author of mine) at the University of Georgia.  Here is the home page of Matthew Bonds.

Thursday assorted links

by  Tyler Cowen

1. The Sahara was once the most dangerous place on earth, and why were there so many carnivorous relative to plant-eating dinosaurs and was that a paradox (Correct link here).

2. This guy documents product placement.

3. Good John Cochrane post about university finances and endowments in particular.

4. Words from Holman Jenkins (WSJ): “Please, if you are a jour­nal­ist re­port­ing on these mat­ters and can’t un­der­stand “flat­ten the curve” as a mul­ti­vari­ate propo­si­tion, leave the pro­fession. You are what econ­o­mists call a “neg­a­tive mar­ginal prod­uct” em­ployee. Your non­par­tic­i­pa­tion would add value. Your par­tic­i­pa­tion sub­tracts it.”

5. Large clusters with low R.

6. Netflix will make another season of Borgen.

7. Swedish public opinion.  And Swedes deter park visitors with horse manure.

8. What can we learn from other coronaviruses?

9. Why so many asymptomatic cases in prison?  And more heterogeneities: why are eastern European death rates so low?

10. How they do things in Iceland.

How tourism will change

by  Tyler Cowen in

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

Some of the safer locales may decide to open up, perhaps with visitor quotas. Many tourists will rush there, either occasioning a counterreaction — that is, reducing the destination’s appeal — or filling the quota very rapidly. Then everyone will resume their search for the next open spot, whether it’s Nova Scotia or Iceland. Tourists will compete for status by asking, “Did you get in before the door shut?”

Some countries might allow visitors to only their more distant (and less desirable?) locales, enforcing movements with electronic monitoring. Central Australia, anyone? I’ve always wanted to see the northwest coast of New Zealand’s South Island.

Some of the world’s poorer countries might pursue a “herd immunity” strategy, not intentionally, but because their public health institutions are too weak to mount an effective response to Covid-19. A year and a half from now, some of those countries likely will be open to tourism. They won’t be able to prove they are safe, but they might be fine nonetheless. They will attract the kind of risk-seeking tourist who, pre-Covid 19, might have gone to Mali or the more exotic parts of India.

And:

laces reachable by direct flights will be increasingly attractive. A smaller aviation sector will make connecting flights more logistically difficult, and passengers will appreciate the certainty that comes from knowing they are approved to enter the country of their final destination and don’t have to worry about transfers, delays or cancellations. That will favor London, Paris, Toronto, Rome and other well-connected cities with lots to see and do. More people will want to visit a single locale and not worry about catching the train to the next city. Or they might prefer a driving tour. How about flying to Paris and then a car trip to the famous cathedrals and towns of Normandy?

Maybe. But I might start by giving Parkersburg, West Virginia, a try.

My Conversation with Glen Weyl

by  Tyler Cowen in

I found it interesting throughout, the first half was on Covid-19 testing, and the second half on everything else.  Here is the audio and transcript.  Here is the summary:

Tyler invited Glen to discuss the plan, including how it’d overcome obstacles to scaling up testing and tracing, what other countries got right and wrong in their responses, the unusual reason why he’s bothered by price gouging on PPE supplies, where his plan differs with Paul Romer’s, and more. They also discuss academia’s responsibility to inform public discourse, how he’d apply his ideas on mechanism design to reform tenure and admissions, his unique intellectual journey from socialism to libertarianism and beyond, the common element that attracts him to both the movie Memento and Don McLean’s “American Pie,” what talent he looks for in young economists, the struggle to straddle the divide between academia and politics, the benefits and drawbacks of rollerblading to class, and more.

Here is one excerpt:

And:

And:

For me the most instructive part was this:

COWEN: What do you view yourself as rebelling against? At the foundational level.

But you will have to read or listen to hear Glen’s very good answer.

Definitely recommended.

Wednesday assorted links and non-links

by  Tyler Cowen

1. New York City parents care about the quality of the peers when choosing a school for their kids, not the effectiveness of the school per se.

2. Secular stagnation vs. technological lull?

3. Dan Klein on Covid and Coase.

4. “Investors are betting, in part, that the Covid-19 crisis accelerates the already growing power of America’s corporate colossuses.” (NYT)

5. NYT covers Sweden.  In my view we still don’t know how well the Swedish experiment is working out, but a continuing verdict of “we still don’t know” does in fact favor Sweden relative to priors.  And Thomas Friedman (NYT) on Sweden.  And update on some Swedish numbers.

6. A reader email on why child abuse is not opposed more passionately: “Basically, I think it comes down to the problem of agency vs structure. The left (including myself) wants to emphasize that problems have large structural components so we need to change the system. However individual heinous acts don’t fit neatly into that paradigm. Plus, child abuse is pervasive enough that it is sort of structural itself, and talking about it can sound like blaming a community or demographic, or hitting close to racism.  No idea why the right doesn’t emphasize it more other than the idea that it’s somehow “traditional”?”

7. Mel Baggs, disability advocate, RIP (NYT).  Formerly known as Amanda Baggs.

8. Quarantine stereotypes (video, funny, some of it).

9. Will colleges lose twenty percent of their student body this year?  Solve for the equilibrium.

10. Jason Furman: “If you had told me we would have a massive pandemic I would have predicted an increase in health spending. Shows why you shouldn’t listen to me. Health spending down 4.9% in Q1 (not annualized). Responsible for nearly 1/2 of the overall GDP decline. Likely down much more in Q2.”  Correctly or not, that makes me feel better about the observed gdp decline.  I am not minimizing the import of the non-Covid extra death toll (which is what exactly? Is it net even positive?), but I already felt bad about that.

Modeling COVID-19 on a network: super-spreaders, testing and containment

by  Tyler Cowen in

These would seem to be some important results:

To model COVID-19 spread, we use an SEIR agent-based model on a graph, which takes into account several important real-life attributes of COVID-19: super-spreaders, realistic epidemiological parameters of the disease, testing and quarantine policies. We find that mass-testing is much less effective than testing the symptomatic and contact tracing, and some blend of these with social distancing is required to achieve suppression. We also find that the fat tail of the degree distribution matters a lot for epidemic growth, and many standard models do not account for this. Additionally, the average reproduction number for individuals, equivalent in many models to R0, is not an upper bound for the effective reproduction number, R. Even with an expectation of less than one new case per person, our model shows that exponential spread is possible. The parameter which closely predicts growth rate is the ratio between 2nd to 1st moments of the degree distribution. We provide mathematical arguments to argue that certain results of our simulations hold in more general settings.

And from the body of the paper:

To create containment, we need to test 30% of the population every day. If we only test 10% of the population every day, we get 34% of the population infected – no containment (blue bars).

As for test and trace:

Even with 100% of contacts traced and tested, still mass-testing of just over 10% of the population daily is required for containment.

The authors are not anti-testing (though relatively skeptical about mass testing compared to some of its adherents), but rather think a combination is required in what is a very tough fight:

Our simulations suggest some social distancing (short of lockdown), testing of symptomatics and contact tracing are the way to go.

That is all from a new paper by Ofir Reich, Guy Shalev, and Tom Kalvari, from Google, Google, and Tel Aviv University, respectively.  Here is a related tweetstorm.  With this research, I feel we are finally getting somewhere.

Human Challenge Trials for vaccines

by  Tyler Cowen in

From an anonymous reader:

As you are of course aware, testing on vaccines for Covid-19 are beginning to be undertaken. The scientific community has seemingly decided that Human Challenge Trials (HCT) where test subjects are directly exposed to the virus following vaccination are unethical, instead using the typical protocol of vaccine/placebo inoculation followed by months of observation in order to observe effectiveness. This seems to me a grave moral error based on the following argument.

1) There exists a large cohort of young, healthy, fully informed, willing participants who would undergo HCT.

2) Given the mortality profile of this disease, these participants would be undertaking an exceptionally small mortality risk (perhaps 5-10 per 100k, based on data from Spain/Italy/NYC, assuming zero vaccine effectiveness).

3) Society deems acceptable other activities with much higher fatality risk (at least 5-10x) in both professional (soldiers, logging workers) and recreational (motorcycling, mountaineering) capacities.

4) HCT would speed up the vaccine testing process by many months, saving tens of thousands of lives and avoiding enormous economic damage.

5) HCT actually poses significantly less risk to participants in terms of allergic reaction or ADE risk compared to a standard testing protocol since the number of participants could be much smaller and they would be medically observed.

I fail to find any ethical justification for the current stance of the medical community, from either a utilitarian or deontological perspective, and believe a highly consequential error is being made. This error may be based on false analogies to past unethical testing practices in history where participants were not informed or willing and danger was significant. The current case bears no ethical resemblance, in my judgement, to these past cases.

The simplest model of such errors is that many members of the biomedical establishment do not wish to have bad feelings about any “sins of commission” and to see their status lowered as a result of “dirty hands,” and the readily criticized logistics of Human Challenge Trials.  Since HCTs do not “feel right” to them, they self-deceive into associating that feeling with a concern for the greater public good.

You should not be surprised to see grave moral errors committed in a crisis, however.  Our “mainstream” protection against grave moral errors, in normal circumstances, simply is that usually we are not given the opportunity to commit them.

I do understand that a Human Challenge Trial does not necessarily suffice to show that a given vaccine is safe.  Nonetheless it should be in the “armor of our discourse,” so to speak, as a morally acceptable alternative.  So if you are a biomedical professional, or a public intellectual, I hope you will speak up.

Here is a Matt Yglesias piece on the urgency of developing a vaccine as quickly as possible.  Eric Weinstein notes that women risk their lives every time they proceed with having children.

Tuesday assorted links

by  Tyler Cowen

1. Revised look at IHME epidemiological predictions.  And public code for the Imperial College model.

2. Very good Derek Thompson piece on the evolution of retail (Atlantic).

3. Pandemic urbanism bibliography.

4. Mulligan, Murphy, and Topel on Covid-related issues.  They think like economists.

5. The role of different occupations in transmitting Covid-19.

6. Osterholm and Olshaker on testing, good piece (NYT).

7. Coronavirus spreading in Africa more slowly than expected (FT but not gated).

8. Forced isolation.

9. How New Zealand responded to the end of lockdown.

Early detection of superspreaders by mass group pool testing

by  Tyler Cowen in

Most of epidemiological models applied for COVID-19 do not consider heterogeneity in infectiousness and impact of superspreaders, despite the broad viral loading distributions amongst COVID-19 positive people (1-1 000 000 per mL). Also, mass group testing is not used regardless to existing shortage of tests. I propose new strategy for early detection of superspreaders with reasonable number of RT-PCR tests, which can dramatically mitigate development COVID-19 pandemic and even turn it endemic. Methods I used stochastic social-epidemiological SEIAR model, where S-suspected, E-exposed, I-infectious, A-admitted (confirmed COVID-19 positive, who are admitted to hospital or completely isolated), R-recovered. The model was applied to real COVID-19 dynamics in London, Moscow and New York City. Findings Viral loading data measured by RT-PCR were fitted by broad log-normal distribution, which governed high importance of superspreaders. The proposed full scale model of a metropolis shows that top 10% spreaders (100+ higher viral loading than median infector) transmit 45% of new cases. Rapid isolation of superspreaders leads to 4-8 fold mitigation of pandemic depending on applied quarantine strength and amount of currently infected people. High viral loading allows efficient group matrix pool testing of population focused on detection of the superspreaders requiring remarkably small amount of tests. Interpretation The model and new testing strategy may prevent thousand or millions COVID-19 deaths requiring just about 5000 daily RT-PCR test for big 12 million city such as Moscow.

Speculative, but I believe this is the future of our war against Covid-19.

The paper is by Maxim B. Gongalsky, via Alan Goldhammer.

Monday assorted links

by  Tyler Cowen

1. “We also looked Iceland-scale mass population testing (i.e. 0.7% of population per day). Such testing would be very helpful for monitoring the epidemic, but unsurprisingly it had a negligible impact on reducing transmission, because cases would be detected too late (if at all)”, link here.

2. Which workers bear most of the burden from social distancing policies?

3. This 1,000-Year-Old Mill Has Resumed Production Due to Demand for Flour.

4. “A model assuming continuous evolution of reproduction rates through imitation errors predicts fertility to fall below replacement levels if death rates are sufficiently low. This can potentially explain the very low preferred family sizes in Western Europe.”

5. BMI is very hard to predict, even with an impressive data set of socioeconomic and genetic factors.

6. Graph of excess deaths in various locales, recommended, and Sweden far from the worst.  Bergamo ouch.

7. Was Portugal early to take care of the nursing home problem?  And Connecticut looking for a nursing home solution (WSJ).

8. Vaccine update.

9. Solving for the equilibrium: “Some of the millions of British workers furloughed during the coronavirus lockdown will be encouraged to take a second job picking fruit and vegetables, the government has said. Giving the daily COVID-19 briefing, Environment Secretary George Eustice said only a third of the migrant workers who normally picked fruit and vegetables were currently in the country.”

10. ComedyCellar podcast with me, Coleman Hughes, Yascha Mounk, others, audio / pod: http://riotcast.com/thecomedycellar and the link to youtube: https://www.youtube.com/watch?v=fNG1FsUdXDw.

11. Which retailers generate the most physical interactions? (Big, internationally known chains)  Might the same be true for restaurants?

12. “The scenario of one million Covid-19 deaths is similar in scale to the decades-long HIV/AIDS and opioid-overdose epidemics but considerably smaller than the Spanish Flu of 1918. Unlike HIV/AIDS and opioid epidemics, the Covid-19 deaths will be concentrated in months rather than spread out over decades.”  Link here.

13. Spanish flu closings were short in duration and didn’t help much.

14. What community colleges do and do not know.  And a list of colleges’ plans.

15. New Mercatus call for Covid-19 short papers.