Saturday, April 4, 2020

The path to disaster is paved by experts - a Covid 19 narrative

The response of governments across developing countries to Covid 19 should count as an example of triumph of theoretical knowledge over practical wisdom. It looks likely to be a triumph of experts at a colossal human cost. 

A few observations about the sequence of events that have brought us here. 

1. The horrifying initial unfolding of events from China and Italy framed a narrative on the SARS-CoV-2 virus. The devastation would play itself out everywhere without immediate and complete lockdown. Experts and their models outbid each other to paint alarming pictures. Some flipped back and forth, and the governments too followed suit. The narrative got globalised.

2. Without questioning whether these models and associated prescriptions were appropriate for developing country contexts, local experts borrowed and extrapolated these models. If the best health system in Europe could not handle the pandemic, the broken health care systems in developing countries would stand no chance. India and Africa would be swamped.

Social media and talking heads in television amplified and disseminated these doomsday prophecies.  This is a representative sample of such alarming tales. Even the more perceptive experts who waste no time to caution against one-size-fits-all approaches in public policy began to sing from the same hymn sheet.

This narrative was further shaped by the democratic nature of the virus itself. In fact, atleast initially, the jet-setting well-off within developing countries were more vulnerable. Being more inclined to trust the experts, their support strengthened the narrative.

3. Governments had no time to react and set their agenda. They therefore had no choice but to act on the forced narrative. To their credit, given the narrative and all the uncertainties and stakes involved, most developing country governments acted with alacrity, though with varying degrees of effectiveness. 

4. What about those models? A model is only as good as the parameters selected and assumptions made. The canonical SIR epidemiological models are extremely limited and does not account for variations across regions and population groups (except for demographics). Take the R0. How does it vary across asymptomatic, pre-symptomatic, and symptomatic cases, across geographies, age groups, racial groups, and so on? Then there is the sample data from which it is developed. In this case, it is mostly from the narrow sample of initial stages in China, South Korea and Italy. 

In these circumstances of uncertainty, sample this, this, and this about the impossibility of reliable modelling. The world of epidemiological modelling was taken over by mathematicians, physicians, and economists and their neat but alarming models zipped around in social media.

5. Experts acknowledge that with infectious diseases "context matters" and they do not "spread the same way everywhere" and across seasons. So what is the conceptual basis for the belief that the infection (and more importantly death) rates are likely to be uniform across the world? 

6. Buttressing the above is the only evidence for now, that of observed emerging reality. And this tells a very different story. A story of two distinct and diverging trajectories of progression of Covid 19 as far as deaths are concerned. One for countries in a latitude band in the northern hemisphere, and another for the rest of the world. Evidence-based policy making dictated the case for a differentiated narrative.

7. Further, the only reliable statistic is the number of deaths. The number of cases are perhaps off by several orders of magnitude. But even governments narratives are being driven by the linear graph of ever-rising number of cases. Never mind that cases have only one way up, and exponentially at that, given greater surveillance and increased testing.

8. Governments are now stuck with lockdowns and a manic popular narrative. Any suggestion of a roll-back can be politically suicidal, given the "exponentially growing" cases. Ask Donald Trump. But the costs of a lockdown are spiralling towards unacceptable levels, as to make an exit in the immediate future inevitable. What are be the exit strategy options to the lockdown chakravyuha? 

9. But the experts and their amplifiers have been doubling down on lockdowns. They uniformly argue in favour of maintaining lockdowns and then following the trace, test, isolate, and treat strategy. Follow the South Korean model. Anything else will be suicidal. 

Even among the experts, the rare exception who tries to buck the dominant narrative gets excoriated by peers. Lockdown and testing has become the dogmatic party line among experts. Even experts have cast off evidence and objectivity and become captives to technical models and fear. 

10. But what is the exit strategy with this expert advice? Never mind the cases, it is a fair assumption that at least a month since the detection of the first case, we are well into community transmission in many developing countries. In the circumstances, what if you test elaborately over the coming few weeks and find that 10 million people are infected? First, do these countries have the resources and state capacity to conduct even anything remotely close to the PCR tests required to validate positive cases (the antibody tests will only validate those infected and cured)? Also what about the reliability (false negatives) of these tests, their interpretation, and challenges with related patient management protocols? If validated, do they have anything even remotely close to the capacity within the health system to keep them isolated? Or is it at all even practical to have them isolated at their homes, with all the social stigma and other associated problems? Imagine the social and communal problems that are likely with having home isolation cases scattered across the country. 

The need of the hour is prudence. One which uses a practical combination of social distancing, multi-pronged testing and isolation strategy, and targeted but limited lockdowns. What are the alternative strategies? Instead of harping on an impractical lockdown-testing strategy, the experts and public intellectuals need to step up to give governments the political cover to pursue a practical exit strategy. Faced with an overwhelming narrative, politicians need this cover now more than ever. Unfortunately, collective prudence is as rare as black swans. 

Granted politicians and bureaucrats do not generally cover themselves with glory. They deserve most of the blame they get. But do we deny that public policy choices in conditions of extreme uncertainty and involving existential considerations are by definition exercise of political judgement, even if informed by science and facts? Or do we want to reduce such decisions to an algorithmic exercise of technocratic thinking? This is a teachable moment.

Update 1 (05.04.2020)

Here is a summary of twelve medical experts who question the panic view on the pandemic.

The Economist points to the superiority of judgement over models in conditions of such uncertainty,
Nicholas Reich of the University of Massachusetts, Amherst, and his colleague Thomas McAndrew have used a questionnaire to ask a panel of experts on epidemics, including many who make models, how they expect the pandemic to evolve... Asked what they were basing their responses on, the experts said it was about one-third the results of specific models and about two-thirds experience and intuition. This offers a way to take the models seriously, but not literally, by systematically tapping the tacit knowledge of those who work with them. In studies run over the course of two flu seasons, such a panel of experts was consistently better at predicting what was coming over the next few weeks than the best computational models.
Update 2 (07.04.2020)

After the lockdown horse has bolted, some of the economists and think tanks are trickling out with their scepticism about models and lockdowns. Universities are scrambling to dissassociate themselves from viral models - again only too late for the scaremongering damage has been done!

In another month, like with models and lockdowns, the world of experts, who are now united in their calls for mass-testing, will gradually trickle out with acknowledgements of their folly on mass testing. For anyone conversant with these contexts, it is just impractical and has no end game.

In the meantime, the one area where expertise could help trigger public debates and inform government is the principles and details of a strategy to exit from lockdowns. Again, by the time experts would have started thinking about this, this horse too would have bolted.

Plumbers have little to offer for real-time policy making but are good at post facto adjudication and castigation of government failures! This speech was an ad-hominem attack which mocked Kerala's health care officials, who today stands tallest fighting the pandemic. 

It is indeed impressive that states like Kerala (with a comprehensive exit strategy) and cities like Chandigarh and Bombay are showing the way with practical and locally relevant exit strategies or elements of them. 

Ananth nails it here in an excellent interview. This is the point,
epidemiologists are incentivised to exaggerate and always stress the worse-case scenarios rather than the better-case scenarios. experts and officials, in the advice they give govts, push worse-case scenarios and not better-case ones. The media picks this up and sensationalises the predictions. Public opinion whips itself into a frenzy. Consequently govts come under irresistible pressure to act on the worse-case basis. This gets further reinforced when all other govts act the same way. No govt or leader wants to act differently.
Update 3 (09.04.2020)

Bibek Debroy urges caution on lockdown and argues against the panic reaction.

Update 4 (10.04.2020)

Based on stories from South Korea, opinion makers have piled pressure on governments in countries like India to undertake mass testing. Forget the lack of end-game, even the reliability of available testing options appear questionable,
But “there are a lot of things that impact whether or not the test actually picks up the virus,” Priya Sampathkumar, an infectious diseases specialist at Mayo Clinic in Minnesota, told AFP. “It depends on how much virus the person is shedding (through sneezing, coughing and other bodily functions), how the test was collected and whether it was done appropriately by someone used to collecting these swabs, and then how long it sat in transport,” she said. The virus has only been spreading among humans for four months and therefore studies about test reliability are still considered preliminary. Early reports from China suggest its sensitivity, meaning how well it is able to return positive results when the virus is present, is somewhere around 60 to 70 percent. “In California, estimates say the rate of COVID-19 infection may exceed 50 percent by mid-May 2020,” she said. With 40 million people, “even if only one percent of the population was tested, 20,000 false-negative results would be expected.” This makes it critical for clinicians to base their diagnosis on more than just the test: they must also examine a patient’s symptoms, their potential exposure history, imaging and other lab work. Part of the problem lies in locating the virus as its area of highest concentration shifts within the body. The main nasal swab tests examine the nasopharynx, where the back of the nose meets the top of the throat. This requires a trained hand to perform and some portion of the false negatives arises from improper procedure. But even if done correctly, the swab may produce a false negative. That’s because as the disease progresses, the virus passes from the upper to the lower respiratory system.
Update 4 (12.04.2020)

Excellent advice from Aruna Sundararajan here, channeling what policy makers would have wanted from experts, 
We can no longer go solely on the basis of international precedent. Nor can our sole consideration be to halt the pandemic, no matter the cost. India’s present lockdown has been rated as the severest in the world and the most disruptive by far, impacting a seventh of the world’s population. Whatever decision we take, we must keep foremost the impact of the lockdown on the poorest and the most vulnerable: For it is they who are likely to bear the brunt... While we know that the COVID pandemic is much more infectious and more virulent than the flu, it is also a widely accepted fact that viral epidemics abate only when around 60-80 per cent of the population acquires “herd-immunity” — either by vaccination or by acquiring the disease... It is incumbent that our experts and advisors present the decision-makers with the full facts, the latest knowledge and insights and a broader array of options rather than merely a single option; namely, to extend or not extend.
Update 5 (26.04.2020)

On coronavirus, the WSJ puts things in perspective (HT: Ananth),
Infectious respiratory diseases are a fact of nature. Beijing was finally driven to action by the same consideration that drove other countries to action—when the number of infected people and the duration of their cases overwhelmed a local hospital system. This is the proximate crisis that called for a public response around the world. Novel pandemic diseases are not a black swan. Our lockdown response was a black swan... "What happened? From Bill Gates to your local editorialist, a new priority waddled to the fore. We decided that, whatever contributes to killing Americans at a routine total rate of 8,000 or so a day, it shouldn’t be the coronavirus. 
Accidents, yes—6% of deaths. Heart disease, yes—23%. Flu and pneumonia, yes—20%.


These deaths are allowed but not deaths from the coronavirus even at the cost of economic ruin for millions. Of course the media and public are free to decide now they never wanted flatten the curve; they wanted to be spared the virus altogether. But explain how this is to be done. And explain why."

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