The meat supply is starting to fail. Meat processing factories seem especially susceptible to COVID-19 probably because of mist, chilled air circulation, the creation of aerosols and close worker contact. What other industries could be affected? What would happen if the energy, transportation, or pharmaceutical sector failed? We aren’t even sure which industries are critical. Who would have thought that nasal swabs would be a critical industry? In researching vaccine production I was stunned to learn that glass vials may be a bottleneck. Glass vials! How then do we best protect the workers in our critical industries? Should everyone else practice social distancing, closing of non-essential firms and work from home or should everyone else return to work as if everything were normal?
Social distancing, closing non-essential firms and working from home protect the vulnerable but these same practices protect workers in critical industries. Thus, the debate between protecting the vulnerable and protecting the economy is moot. “Lockdowns” protect vulnerable people and protect vulnerable industries. Save grandma, save the economy.
The point is simple but made formally in Social Distancing and Supply Disruptions in a Pandemic by Bodenstein, Corsetti and Guerrieri.
Abstract: Drastic public health measures such as social distancing or lockdowns can reduce the loss of human life by keeping the number of infected individuals from exceeding the capacity of the health care system but are often criticized because of the social and economic costs they entail. We question this view by combining an epidemiological model, calibrated to capture the spread of the COVID-19 virus, with a multisector model, designed to capture key characteristics of the U.S. Input Output Tables. Our two-sector model features a core sector that produces intermediate inputs not easily replaced by inputs from the other sector, subject to minimum-scale requirements. We show that, by affecting workers in this core sector, the high peak of an infection not mitigated by social distancing may cause very large upfront economic costs in terms of output, consumption and investment. Social distancing measures can reduce these costs, especially if skewed towards non-core industries and occupations with tasks that can be performed from home, helping to smooth the surge in infections among workers in the core sector.
Addendum: I wrote “lockdowns” because I am in favor of getting back to work with mass testing and safety protocols so I don’t think that a “lockdown” is necessarily the optimal policy. Indeed, I think we could get the meat processors back up and running with testing at the door and safety protocols. But we are not having a rational discussion about the tools and the investments that we need to reopen the economy. Instead, the people protesting to reopen the economy are also protesting against the use of a key tool to reopen the economy, masks! Welcome to crazy town.
My viewing habits are less hi-brow than Tyler’s, perhaps especially now when I am seeking escape and mind rest. Here’s a few things I have enjoyed and some that I have not.
DEVS on Hulu. If you know what the Everett interpretation is you will probably enjoy this science-fiction drama with big ideas on quantum computing and free will but also enough suspense, action and human relationships to drive the drama forward. From the director of Ex Machina. Sonoya Mizuno steals the show, super charismatic in an off beat way.
Westworld on HBO. A few interesting scenes but mostly disappointing.
Formula 1: Drive to Success on Netflix. I have no real interest in car racing but this documentary–each season is a season–is very well produced. Great shots from within the cars and each episode is tightly crafted, dare I say formulaic, so you want to watch the next. Popcorn but good popcorn. An extended version of Rush. I had no idea a team can cost $300-$500 million a year.
Bosch on Amazon. A police noir set in the real Los Angeles. Bosch is the Sisyphus of police detectives, driven to find justice for the victims but the victims never thank him, justice doesn’t bring them back and each day brings another. A study in character.
Extraction on Netflix. Awful. Brainless. If you want action, watch Fauda about a special Israeli Defense Unit. It’s well done and you will learn something even if what you will learn is how decent people turn into terrorists in an endless cycle of retribution and misery.
Impostors on Neflix: A light con-woman caper. Good for one season but harder to sustain once you’ve seen behind the curtain.
Beforeigners on HBO: My only share with Tyler. I look forward to a second season.
Top Chef on Amazon (I bought the new Season). Still my go to for competence-porn and don’t we all need some of that? Plus makes me look forward to restaurants.
The COVID-19 crisis is accelerating a long-term trend, the shift to online education. I’ve long argued that online education is superior to traditional models. In an excellent essay in the New York Times, Veronique Mintz, an eighth-grade NYC student agrees:
Talking out of turn. Destroying classroom materials. Disrespecting teachers. Blurting out answers during tests. Students pushing, kicking, hitting one another and even rolling on the ground. This is what happens in my school every single day.
You may think I’m joking, but I swear I’m not…during my three years of middle school, these sorts of disruptions occurred repeatedly in any given 42-minute class period.
That’s why I’m in favor of the distance learning the New York City school system instituted when the coronavirus pandemic hit.
…Distance learning gives me more control of my studies. I can focus more time on subjects that require greater effort and study. I don’t have to sit through a teacher fielding questions that have already been answered.
…This year I have struggled with math. The teacher rarely had the patience for questions as he spent at least a third of class time trying to maintain order. Often, when I scheduled time to meet with him before school, there would be a pileup at his door of students who also had questions. He couldn’t help us all in 20 minutes before first period. Other times he just wouldn’t show up….With distance learning, all of that wasted time is eliminated. I stop, start and even rewind the teacher’s recording when I need to and am able to understand the lesson on the day it’s taught.
Veronique’s online courses were put together in a rush. Imagine how much more she will learn when we invest millions in online classes and teach at scale. The online classes that Tyler and I teach, using Modern Principles and the Sapling/Achieve online course management system, took years to produce and feature high quality videos and sophisticated assessment tools including curve shifting (not just multiple-choice), empirical questions based on FRED, and adaptive practice–plus the videos are all subtitled in multiple languages, they can be sped up or slowed down, watched at different times of the day in different time zones and so forth. Moreover, technology is increasing the advantages of online education over time.
Today in the New York Times I have an op-ed with Susan Athey, Michael Kremer and Christopher Snyder. We argue for a big program to invest in vaccine capacity before any vaccine is tested and approved. We agree with Bill Gates that we want the vaccine factories to be warmed up by the time a vaccine is approved. We can’t leave it all to Gates, however. The US economy is hemorrhaging $150-$350 billion a month so the benefits of a vaccine to society are huge and we should go big.
Today, the U.S. government could go big and create a Covid-19 vaccine A.M.C., guaranteeing to spend about $70 billion on new vaccines — enough to make direct investments to support capacity installation or to repurpose capacity and to pay, say, $100 per person for the first 300 million people vaccinated.
An investment of that size can anticipate and overcome several challenges typical of vaccine development. If we want to achieve a 90 percent probability of success, we must take into account historical rates of success from publicly available data; doing that suggests that we need to actively pursue not two or three vaccine candidates, but 15 to 20.
…Usually, to avoid the risk of investing in capacity that eventually proves worthless, firms invest in large-scale capacity only after the vaccine has proved effective. But in the middle of a pandemic, there are huge social and economic advantages to having vaccines ready to use as soon as they have been approved. If we leave it entirely to the market, we will get too little vaccine too late.
An advance market commitment for Covid-19 should combine “push” and “pull” incentives. The “pull” incentive is the commitment to buy 300 million courses of vaccine at a per-person price of $100, for vaccines produced within a specified time frame. If multiple vaccines are developed, the A.M.C. fund will have authority to choose products to purchase based on efficacy, the availability of sufficient vaccine for timely vaccination or suitability for different population groups. So firms compete to serve the first 300 million people with the most attractive vaccines, and the “pull” component provides strong incentives for both speed and quality.
The “push” incentive guarantees firms partial reimbursement for production capacity built or repurposed at risk and partial reimbursement as they achieve milestones. The partial reimbursement ensures that manufacturers have “skin in the game,” while inducing them to build large-scale capacity before approval is certain.
More than usual, read the whole thing and please do help to circulate the ideas by posting and tweeting.
The op-ed draws on the work of a large team of economists and statisticians who have been working days and nights for weeks. You can find out more at AcceleratingHT where we will soon be posting additional analysis and tools.
It’s a great privilege for me to be working with this group. One day I will write the story but for now let me just say that I have never seen such a brilliant and dedicated group come together to apply their skills to a problem of such importance and urgency.
The Coronavirus Pandemic may be the most warned about event in human history. Surprisingly, we even did something about it. President George W. Bush started a pandemic preparation plan and so did Governor Arnold Schwarzenegger in CA but in both cases when a pandemic didn’t happen in the next several years those plans withered away. We ignored the important in favor of the urgent.
It is evident that the US government finds it difficult to invest in long-term projects, perhaps especially in preparing for small probability events with very large costs. Pandemic preparation is exactly one such project. How can we improve the chances that we are better prepared next time?
…we would like organizations tasked with protecting the public from low-probability, high-cost events to be funded on a permanent basis that is not subject to budgetary discretion or degradation. Instead of yearly appropriations, it’s preferable to have a one-time appropriation to finance a stream of investments. The financial means of doing this is to buy a bond with an earmarked revenue stream. That is, instead of selling bonds the government buys long-term safe bonds which pay out dividends that are earmarked to a program, in this case to pandemic preparation.
There is a well-known example of such a financing scheme, the social security trust fund. The social security trust fund was established in 1937. It buys long-term safe bonds that pay dividends that are used to finance social security payments. Unlike the pandemic trust fund I propose, the Social Security Trust Fund buys bonds on an ongoing basis but that is a relatively unimportant difference.
The Social Security Trust Fund buys the safest form of government bonds, which has given rise to a long-standing controversy over whether the trust fund is a “fiction.”10Of course, the trust fund is a kind of fiction but so are federalism, checks and balances, and the Constitution. Fictions can be powerful because they create shared understandings that govern behavior and determine equilibrium action. The trust fund does what it says—it increases trust by indicating that Social Security payments are higher in creditor priority than other spending. Just as Section 507 of the Bankruptcy Code increases trust by indicating that secured bondholders get paid before unsecured creditors such as a company’s suppliers. Since 1937, the Social Security Trust Fund has always held net assets, and when it briefly ran deficits in the 1970s and early 1980s, the Greenspan commission was established to shore up the system.11 That is, the simple existence of the Trust Fund as an accounting entity created an awareness, which made it easier to act to maintain the Fund.
A Pandemic Trust Fund would begin with a $250 billion investment in bonds earmarked to pandemic preparations. At current effective rates of interest of about 3%, this is enough to support spending of $7.5 billion annually.12 Note that $7.5 billion is nowhere near enough to address the current pandemic, but that is because we did not invest enough in pandemic preparation. Had we invested $7.5 billion in pandemic preparation every year for the last two decades, for example, we would be in much better shape today. The $7.5 billion is for annual ongoing preparation.
…A Pandemic Trust Fund invested in $250 billion of government bonds is an accounting fiction that may be readily agreed upon today at the height of the crisis because it has few current costs. Yet, as we have discussed, accounting fictions can have real power in changing the future allocation of resources.
Read the whole thing, it is also includes some interesting info on clever DOD contracts that have advanced pandemic preparations.
NYTimes: Around the world, scientists are racing to develop and mass produce reliable antibody tests that public health experts say are a crucial element in ending the coronavirus lockdowns that are causing economic devastation. But that effort is being hamstrung, scientists say, by a shortage of the blood samples containing antibodies to Covid-19, the disease caused by the virus, that are needed to validate the tests.
Recognizing a rare opportunity, some companies are seeking to cash in on the shortages, soliciting blood donations and selling samples at rich markups in a practice that has been condemned by medical professionals as, at the very least, unethical.
“I’ve never seen these prices before,” said Dr. Joe Fitchett, the medical director of Mologic, one of the British test manufacturers that was offered the blood samples. “It’s money being made from people’s suffering.”
I am reminded of Walter Williams who asks his students whether it is wrong to profit from the misfortune of others:
But I caution them with some examples. An orthopedist profits from your misfortune of having broken your leg skiing. When there’s news of a pending ice storm, I doubt whether it saddens the hearts of those in the collision repair business. I also tell my students that I profit from their misfortune — their ignorance of economic theory.
A price is a signal wrapped up in an incentive so if you want a strong signal and a strong incentive you need to let prices rise. The prices in this case don’t even seem that high:
From March 31 to April 22, prices asked by Cantor BioConnect for its cheapest samples — always sold by the milliliter, the equivalent of less than a quarter of a teaspoon — rose more than 40 percent, to $500 from $350.
Bear in mind the costs of collecting the sample, including nurse time and PPE. Some samples which are especially rich in antibodies, do sell for prices that are well above cost which is not surprising as those samples are in high demand as they may offer a cure.
Do the firms willing and able to pay the highest prices necessarily have the best science? No, not necessarily, but on balance the decentralized allocation process offered by markets and civil society will likely be far more effective than centralized, political allocation. We also know from field experiments around the world that higher prices for blood increase supply, a key consideration.
As Hayek said the moral rules of the tribe which appear natural to us–like don’t profit from misery–cannot maintain a civilization so we struggle between what we think is right and what actually works to prevent misery.
There can be no doubt that our innate moral emotions and instincts were acquired in the hundreds of thousand years—probably half a million years—in which Homo sapiens lived in small hunting and gathering groups and developed a physiological constitution which governed his innate instincts. These instincts are still very strong in us. Yet civilization developed by our gradually learning cultural rules which were transmitted by teaching and which served largely to restrain and suppress some of those natural instincts.
MRU introduces a new series, Economists in the Wild. In this series, we talk with economists in widely varying fields about their cutting edge research. First up in the series is David Autor on the rise of superstar firms and the fall of the labor share.
More great material for your online economics seminars and a great resource to use with Modern Principles!
Mitch Daniels, the President of Purdue, has outlined a preliminary plan to reopen involving test, trace and supported isolation on campus.
We intend to know as much as possible about the viral health status of our community. This could include pre-testing of students and staff before arrival in August, for both infection and post-infection immunity through antibodies. It will include a robust testing system during the school year, using Purdue’s own BSL-2 level laboratory for fast results. Anyone showing symptoms will be tested promptly, and quarantined if positive, in space we will set aside for that purpose.
We expect to be able to trace proximate and/or frequent contacts of those who test positive. Contacts in the vulnerable categories will be asked to self-quarantine for the recommended period, currently 14 days. Those in the young, least vulnerable group will be tested, quarantined if positive, or checked regularly for symptoms if negative for both antibodies and the virus.
This paper provides details on transforming a university lab into a testing center. In essence, a major university with a hospital (which Purdue doesn’t have) should be able to do it technically but to work to reopen for students it probably has to be a university located outside of a major urban area. Here are a few possibilities:
- Baylor University
- Vanderbilt University
- University of Michigan, Ann Arbor
- University of Virginia
- University of Iowa
- University of Utah
- University of Alabama
Mitch Daniel also notes:
Our campus community, a “city” of 50,000+ people, is highly unusual in its makeup. At least 80% of our population is made up of young people, say, 35 and under. All data to date tell us that the COVID-19 virus, while it transmits rapidly in this age group, poses close to zero lethal threat to them.
which does seem to miss (ahem) an important group necessary for reopening.
Many people claim that commodification, transforming a good or activity into a commodity bought and sold on a market, corrupts that good or activity. As Michael Sandel puts it:
Putting a price on the good things in life can corrupt them. That’s because markets don’t only allocate goods; they express and promote certain attitudes toward the goods being exchanged.
But few people have tested this idea which is why I loved Stephen Clowney’s Does Commodification Corrupt? Lessons from Paintings and Prostitutes. Clowney does something simple. He interviews art appraisers and male escorts, people who live with commodification, and asks them about art and sex. In short he uses the “lived experiences of those affected by commodification” to test whether commodification corrupts.
Does appraising art, for example, reduce the appraiser’s appreciation for art the way working in a pork factory might reduce a worker’s appetite for bacon?
Scott Altman, a legal scholar who has studied commodification, perfectly captures the standard market skeptic position: “[s]omeone who spends all day estimating the value of art might eventually have difficulty appreciating art in any way other than as worth a certain amount.”
What does Clowney find?
Of the twenty assessors interviewed for this study, not one reported that market work disfigured their ability to enjoy the emotional, spiritual, and aesthetic qualities of artistic masterworks. In fact, most appraisers insisted they can easily and completely compartmentalize their professional duties from their private encounters with art. This finding challenges the panicked rhetoric of many anti-commodification theorists who continue to insist that commerce diminishes the meaning of sacred things. Contrary to the predictions of market skeptics, the appraisers in this study spoke with joyful enthusiasm about their experiences viewing exceptional works of art. Even the most senior appraisers—those who have monetized thousands and thousands of objects—remain passionate consumers of art in their personal lives.
…Jane C.H. Jacob, an appraiser with thirty-five years of experience, explained, “[the appraisal work] does not corrode my enjoyment at all. I never get tired of looking at art. Never bored. I love art more now than I did 20 years ago.” She continued, “[f]or me, the joy is being able to experience it and inspect it. Listen, I don’t love art because of the price, but because of the way I respond to it. When I see [Monet’s] Water Lilies I never don’t get excited. A tear comes to my eye.”
In fact “a majority of the assessors stated that ascribing values to art actually increased their admiration for paintings, photographs, sculptures, and other creative work.”
But how could that be so? Given the widely reported dangers of commodification, how could non-instrumental values blossom in the hard soil of the marketplace? Anti-commodification scholars, it seems, have failed to appreciate that market work is a powerful educational agent that breaks the stale cake of ignorance, turns apathy into understanding, and nurtures new insights about the sacred. Imagine, for example, an appraiser confronted with attaching value to Mary Cassatt’s painting, Young Mother Sewing. Anyone attempting to price such an object must, at the outset, become well-versed in the artist’s career, the provenance of the work, and the ethos of the larger impressionist movement. Then, the appraiser must probe to explain whether the painting is a “good, better, or best” example of Cassatt’s work.
… Arch-anti-commodificationist Elizabeth Anderson even suggests that those who engage in ranking and valuation of art are “philistines, snobs, and prigs, precisely those least open to a free exploration and development of their aesthetic sensibilities.” But that is quite wrong. Commodification does not render these artworks flat and fungible. And it is not carried out by Philistines. Just the opposite. Putting an accurate price on sacred objects demands education, rigorous training, and cultivation of the eye. Appraisers must understand the objects on an intimate level in order to properly evaluate their quality and make suitable comparisons between seemingly disparate works. Such knowledge only enhances appreciation for the way that creative work can exhilarate, sooth, baffle, enlighten, and uplift.
See also Tyler’s classic In Praise of Commercial Culture on these points.
What about sex?
In a sprawling literature, commentators have argued that exchanging sex for money “commodif[ies] sexuality,” degrades intimacy, “impedes human flourishing,” and foments attitudes that undermine the sacredness of the body. In short: market skeptics believe that prostitution corrupts the meaning of sex.
Clowney interviewed male escorts because he argues that the market in male escorts is freer and more developed. Male escorts, for example, are less likely to be abused by the police or pimps. Some will question that choice but for the purposes of the commodification theory it should still be the case that commodification degrades sex for the male escorts. Does it?
…the escorts I interviewed insisted that selling physical intimacy did not corrupt their understanding of sex. While the physical demands of the job often left the interviewees feeling exhausted, each of the prostitutes revealed that they continued to experience the loving (and joyfully profane) virtues of the sexual act. Indeed, a majority of escorts confided that their market work positively impacted their private lives—commercial sex honed their sexual skills, boosted their confidence, and deepened their understanding of other men.
… For these men, sex remained a joyful and cherished activity, even after years of selling their bodies.… A strong majority of the escorts reported that engaging in commercial sexual activities actually improved the quality of their private lives and their appreciation for sacred things.Just as appraisal work revealed new insights about the creative process, prostitution taught the interviewees about the complexity of desire, gave them a deeper understanding of the sexual act, and enhanced their ability to satisfy a private partner.
… Thus, far from turning sex into a flat and interchangeable commodity, market work deepened the escorts’ understanding of physical intimacy. Sex work instilled the importance of honest communication between partners, revealed that men have many different (and often colorful) needs, and showed that not all fantasies can be met by working off the same script. On these points, the market is an exacting teacher.
Clowney’s paper is a highly original, major new work in the commodification literature and contains much more of interest. Read the whole thing.
The latest relief bill contains another $320 billion in small business relief and $25 billion for testing. Finally, we get some serious money to actually fight the virus. But as Paul Romer pointed out on twitter, this is less than half of what we spend on soft drinks!!! (Spending on soft drinks is about $65 billion annually). Soda is nice but it is not going to save lives and restart the economy. Despite monumental efforts by BARDA and CEPI we are also not investing enough in capacity for vaccine production so that if and when when a vaccine is available we can roll it out quickly to everyone (an issue I am working on).
The failure to spend on actually fighting the virus with science is mind boggling. It’s a stunning example of our inability to build. By the way, note that this failure has nothing to do with Ezra Klein’s explanation of our failure to build, the filibuster. Are we more politically divided about PCR tests than we are about unemployment insurance? I don’t think so yet we spend on the latter but not the former. The rot is deeper. A failure of imagination and boldness which is an embarrassment to the country that put a man on the moon.
In Launching the Innovation Renaissance I said the US was a welfare/warfare state and no longer an innovation state. The share of R&D in the Federal Budget, for example, has diminished from about 12% at its height in the NASA years to an all time low of about 3% in recent years. We are great at spending on welfare and warfare but all that spending has crowded out spending on innovation and now that is killing us.
For 28 days, they did not leave — sleeping and working all in one place.
In what they called a “live-in” at the factory, the undertaking was just one example of the endless ways that Americans in every industry have uniquely contributed to fighting coronavirus. The 43 men went home Sunday after each working 12-hour shifts all day and night for a month straight, producing tens of millions of pounds of the raw materials that will end up in face masks and surgical gowns worn on the front lines of the pandemic.
…Nikolich said the plants decided to launch the live-ins so employees could avoid having to worry about catching the virus while constantly traveling to and from work, and so the staff at the factory could be closed off to nonessential personnel.
The article also indicates why price increases are critical to increase supply:
They were paid for all 24 hours each day, with a built-in wage increase for both working hours and off time, the company said. It did not disclose the specific percentages.
Hat tip: Jonathan Meer.
Earlier I suggested that that we offer unemployed people jobs that could be done from home:
A 21st century jobs program would pay people to stay home and isolate, support people without work, and produce some useful output all at the same time.
Writing at Brookings, Apurva Sanghi and Michal Lokshin provide some more ideas:
Another high-potential area is document digitization: Only 10 percent of the world’s books are digitized. Even with the current level of optical character recognition (OCR) technology, for a book to be digitized, an independent person needs to check it for errors, problems with tables and images, tagging, and oversee the look of the resulting text. Handwritten documents, images, and tables, even in printed books, require manual processing, proofreading, careful checking, and quality control. A person would receive scanned images of, let’s say, old letters to decipher and type into the electronic document. Comparing the results of several independent people working on the same document would assure the quality of transcription.
I want to add one more item to the list: contact tracing. In addition to tracing apps, we are going to need hundreds of thousands of people doing contact tracing and most of it can be done with email and phone from home. Two birds, one stone.
Rapid and accurate SARS-CoV-2 diagnostic testing is essential for controlling the ongoing COVID-19 pandemic. The current gold standard for COVID-19 diagnosis is real-time RT-PCR detection of SARS-CoV-2 from nasopharyngeal swabs. Low sensitivity, exposure risks to healthcare workers, and global shortages of swabs and personal protective equipment, however, necessitate the validation of new diagnostic approaches. Saliva is a promising candidate for SARS-CoV-2 diagnostics because (1) collection is minimally invasive and can reliably be self-administered and (2) saliva has exhibited comparable sensitivity to nasopharyngeal swabs in detection of other respiratory pathogens, including endemic human coronaviruses, in previous studies. To validate the use of saliva for SARS-CoV-2 detection, we tested nasopharyngeal and saliva samples from confirmed COVID-19 patients and self-collected samples from healthcare workers on COVID-19 wards. When we compared SARS-CoV-2 detection from patient-matched nasopharyngeal and saliva samples, we found that saliva yielded greater detection sensitivity and consistency throughout the course of infection. Furthermore, we report less variability in self-sample collection of saliva. Taken together, our findings demonstrate that saliva is a viable and more sensitive alternative to nasopharyngeal swabs and could enable at-home self-administered sample collection for accurate large-scale SARS-CoV-2 testing.
The FDA has also just approved an at-home test collected by nasal swab, a saliva test should not be far behind.
Hat tip: Cat in the Hat.
Led by Danielle Allen and Glen Weyl, the Safra Center for Ethics at Harvard has put out a Roadmap to Pandemic Resilience (I am a co-author along with others). It’s the most detailed plan I have yet seen on how to ramp up testing and combine with contact tracing and supported isolation to beat the virus.
One of the most useful parts of the roadmap is that choke points have been identified and solutions proposed. Three testing choke points, for example, are that nasal swaps make people sneeze which means that health care workers collecting the sample need PPE. A saliva test, such as the one just approved, could solve this problem. In addition, as I argued earlier, we need to permit home test kits especially as self-swab from near nasal appears to be just as accurate as nasal swabs taken by a nurse. Second, once collected, the swab material is classified as a bio-hazard which requires serious transport and storage safety requirements. A inactivation buffer, however, could kill the virus without killing the RNA necessary for testing and thus reduce the need for bio-safety techniques in transportation which would make testing faster and cheaper. Finally, labs are working on reducing the reagents needed for the tests.
Understanding the choke points is a big step towards increasing the quantity of tests.
In a post titled Defensive Gun Use and the Difficult Statistics of Rare Events I pointed out that it’s very easy to go wrong when estimating rare events.
Since defensive gun use is relatively uncommon under any reasonable scenario there are many more opportunities to miscode in a way that inflates defensive gun use than there are ways to miscode in a way that deflates defensive gun use.
Imagine, for example, that the true rate of defensive gun use is not 1% but .1%. At the same time, imagine that 1% of all people are liars. Thus, in a survey of 10,000 people, there will be 100 liars. On average, 99.9 (~100) of the liars will say that they used a gun defensively when they did not and .1 of the liars will say that they did not use a gun defensively when they did. Of the 9900 people who report truthfully, approximately 10 will report a defensive gun use and 9890 will report no defensive gun use. Adding it up, the survey will find a defensive gun use rate of approximately (100+10)/10000=1.1%, i.e. more than ten times higher than the actual rate of .1%!
Epidemiologist Trevor Bedford points out that a similar problem applies to tests of COVID-19 when prevalence is low. The recent Santa Clara study found a 1.5% rate of antibodies to COVID-19. The authors assume a false positive rate of just .005 and a false negative rate of ~.8. Thus, if you test 1000 individuals ~5 will show up as having antibodies when they actually don’t and x*.8 will show up as having antibodies when they actually do and since (5+x*.8)/1000=.015 then x=12.5 so the true rate is 12.5/1000=1.25%, thus the reported rate is pretty close to the true rate. (The authors then inflate their numbers up for population weighting which I am ignoring). On the other hand, suppose that the false positive rate is .015 which is still very low and not implausible then we can easily have ~15/1000=1.5% showing up as having antibodies to COVID when none of them in fact do, i.e. all of the result could be due to test error.
In other words, when the event is rare the potential error in the test can easily dominate the results of the test.
Addendum: For those playing at home, Bedford uses sensitivity and specificity while I am more used to thinking about false positive and false negative rates and I simplify the numbers slightly .8 instead of his .803 and so forth but the point is the same.