How to Misuse Global COVID-19 Statistics

Have you heard about Somalia's COVID-19 policy?

In the official statistics, Somalia has just 3,362 confirmed infections and 97 confirmed deaths from COVID-19. On a per capita basis, the country has a death toll just barely above New Zealand, and below other widely reported success stories like South Korea, Japan, Norway, Germany, etc.

Yet, my guess is you probably have not heard much about how Somalia defeated the coronavirus. Why is that?

The reason is that, implicitly, no one thinks Somalia's statistics reflect the underlying reality. Still the recurring target of US drone strikes and dealing with internal conflict, Somalia--like many other impoverished or conflict-torn countries around the world--has little capacity to deal with COVID-19.

Thus, their numbers probably aren't low because they came up with a uniquely successful strategy. They're low because they aren't counting.

The Implications of Incomplete Data

All of this may seem obvious. However, the implications of this observation are routinely forgotten in reports on the coronavirus.

The problem is two-fold: First, Somalia is not an isolated example. There are numerous countries around the world with extremely low case numbers that are almost certainly caused by a lack of testing and counting, not actual policy success. Second, all of these same statistics roll up into the official global COVID-19 totals.

While everyone seems to recognize that numbers from Somalia and others are not real, they forget that this necessarily means that the global totals are also compromised.

We see versions of this error constantly, but here are a couple examples to watch out for.

CNN: The US has 4% of the world's population but 25% of its coronavirus cases

Depending on the date of the article and metric chosen (cases vs. deaths), the second percentage in this claim will fluctuate somewhat. The point is to show that the US accounts for a disproportionate share of damage caused by the coronavirus. That general claim is valid, but the uncritical use of global statistics greatly exaggerates the disparity.

According to Worldometers, approximately 1.5 billion people live in countries where very limited testing (less than 1% of population) has been done. Additionally, some large countries like India only recently ramped up their testing program, and still have totals well below the US for the moment.

This line is a standard inclusion in many stories on the coronavirus. The article used above is slightly unique only because it led with it in the headline.

NYT: America's Death Gap

Here, The New York Times can be commended for at least making a passing reference to the old missile gap canard. Hopefully, this tipped readers off to the fact that what they were about to read was not true.

In the piece, the Times offers the following thought experiment:

If the United States had done merely an average job of fighting the coronavirus — if the U.S. accounted for the same share of virus deaths as it did global population — how many fewer Americans would have died?

The answer: about 145,000. 

That’s a large majority of the country’s 183,000 confirmed coronavirus-related deaths.

The problem with this is not that their math is wrong; the problem is that they're relying on figures that everyone--including them--knows or should know to be unreliable.

As of this writing, the official global average COVID-19 death toll is 114 per 1M people. But this figure is severely diluted by all the countries that have large populations and limited testing.

If we were to treat this global average as a real number, we are left with some rather implausible conclusions.

Yes, the US is much worse than official average with 583 deaths per 1M. Fair enough.

But the same goes for countries like Canada and Switzerland which have 242 and 232 deaths per 1M, respectively. Does anyone think Canada has performed twice as bad as the average country in this pandemic?

Likewise, oft-praised countries like Germany (112)  and Denmark (108) appear to be only marginally better than average. Are we to believe these countries weren't very successful after all?

No one thinks these other conclusions are true, but it follows from the Times' line of analysis. The absurdity of the global average only becomes obvious when it's compared to the results of other countries that are known as success stories.

Conclusion

The point here is not to defend the US's track record on the coronavirus. It has performed abysmally on every conceivable metric, albeit not literally the worst. (That dubious honor belongs to Peru, with Belgium a close second.)

Rather, this is an argument for basic data literacy. If the details of a data set are unreliable, they don't magically become reliable when you sum them up or pass them through an econometric model. Garbage in means garbage out.

We live in a time when almost every politician and pundit says we need to "follow the data". Perhaps we should start by understanding its limitations.

Is Sweden's COVID-19 Response a Cautionary Tale or a Model to Follow? It's Complicated

In the ongoing debate about lockdowns in the US, Sweden has become the battleground.

To mainstream media outlets, Sweden's experience is cited as a cautionary tale. CBS writes that Sweden has become "an example of how not to handle COVID-19".

Meanwhile, to those who have been skeptical of the lockdown policy all along, Sweden's results are occasionally cited in glowing terms. For instance, Jeffrey Tucker of AIER tweeted this out last week, showing that Sweden's daily death toll has slowed to a crawl:

Sweden! No lockdowns, no school closures. Life went on normally, thanks to expert medical advice not to disrupt life. pic.twitter.com/BUbM8PjTsA

— Jeffrey A Tucker (@jeffreyatucker) July 20, 2020

So which version is true?

Did Sweden's less restrictive approach to COVID-19 usher in the hellscape that US public health officials have warned us about? Or is it actually a model for the rest of us to follow?

It's too soon to know for sure. But the data we have so far suggests the answer is not black-and-white.

The Problem of Cherry-Picking
In the CBS article, they point to the per capita COVID-19 death toll in Sweden to declare it a policy failure. Writing last month on July 17, CBS notes:

...the death toll from Sweden's outbreak is now the fifth-worst in the world, per capita. The country's mortality rate from the coronavirus is now 30% higher than that of the United States when adjusted for population size.

On that date, this was true. It is missing some important context, however.

For starters, if Sweden was fifth-worst in the world, why is the article about Sweden? If the point is to identify some COVID-19 policies that clearly failed, there would seem to be at least four candidates just as worthy of criticism.

Excluding the tiny nation-states of Andorra and San Marino, the four European countries that had experienced higher per capita death tolls than Sweden at the time of CBS's piece were Belgium, UK, Spain, and Italy. In the last two weeks, Peru has also overtaken Sweden in terms of per capita death tolls.

All of these countries imposed lockdown policies, and still experienced death tolls higher than Sweden. Italy might have an excuse as the first major hotspot in Europe, but what accounts for the others?

This selective criticism of Sweden by mainstream media has been called out elsewhere with good reason. This is classic cherry-picking--finding facts to fit a predetermined narrative.

To be fair, Sweden's proponents can also be guilty of omitting context.

In the tweet noted above, Tucker points to very low rates of new deaths as a sign of success. This is good news, but it doesn't tell us much. It's widely understood that viruses will burn themselves out eventually. The lockdown debate is about how best to mitigate the damage in the meantime.

In another example, this tweet from Yinon Weiss, favorably compares the experience of Sweden to New York. The comparison is correct--Sweden has fared far better than New York on a per capita basis. However, this is better evidence of New York's extreme failure rather than Sweden's success. If we draw sweeping conclusions from this data point, then it's just cherry-picking in the other direction.

Here’s the good news: You can shut down businesses or keep them open. Close schools or stay in session. Wear masks or not. The virus will make its way through in either case, and if we protect the elderly then deaths will be spared. pic.twitter.com/AVg0Vu8aH2

— Yinon Weiss (@yinonw) July 13, 2020

Obviously, writing a tweet is different than writing an article. Twitter isn't exactly built for nuance.

The point is that, so far, Sweden's results are mixed. They don't warrant a victory lap for anyone.

Voluntary Versus Coercive
While Sweden seems to be viewed by the rest of the world as a radical experiment when it comes to COVID-19, that's not how Sweden sees itself.

Speaking to Nature magazine early on in the pandemic, Sweden's state epidemiologist Anders Tegnell explained bluntly, "I think it has been overstated how unique [Sweden's] approach is."

For Tegnell, Sweden's policy objective is the same as for most other Western countries--flatten the curve to avoid overrunning the healthcare system.

The primary difference is in Sweden's laws. As he explained in the interview (emphasis added):

The Swedish laws on communicable diseases are mostly based on voluntary measures — on individual responsibility...This is the core we started from, because there is not much legal possibility to close down cities in Sweden using the present laws.

By itself, this almost implies that Sweden would have been just as coercive as other countries if they had the authority. (And as an American, it sounds extremely odd to hear a national government official acknowledge any legal constraints on their power. But I digress.)

However, in a separate April interview with Haaretz, Tegnell argued that the voluntary approach has strategic advantages over coercion. In particular, Tegnell noted that the voluntary measures could be kept in place for an extended period of time. In his words, "We believe that what we are doing is more sustainable and effective in the long term."

The Importance of Sustainability

Like most other countries, Sweden's experts share the view that the virus will only stop being a threat once herd immunity is reached or an effective vaccine is developed. "Every other solution is temporary," Tegnell told Haaretz.

Since both of those solutions are likely months away, the sustainability of the policy response is critical. This is why Sweden's approach might ultimately prove more successful than its peers.

Although Tegnell doesn't say this outright, the subtext of Sweden's approach seems to be that all countries' COVID-19 policies will look like Sweden's eventually.

The lockdowns cannot eradicate the virus on their own and cannot be kept in place indefinitely. That means that when the lockdowns are inevitably relaxed, the virus is still around and able to spread.

When the virus starts to spread anew, the authorities in most democratic countries won't have the political ability to reimpose lockdowns. So their only real option is to impose lighter, mostly voluntary measures like Sweden has done from the start. 

Unfortunately, this is how things have played out in many places..

Consider the United States. Many states closed down before they had significant spread and reopened while new infections remained at low, but nonzero, levels. Now cases have surged in several states, and the lockdown measures being reimposed are far less strict than those enforced early on. Noncompliance is also on the rise. 

Today, most states' lockdown policies are still more restrictive than Sweden's. But this does show the unsustainable nature of the prior approach. Given that the states have landed on less restrictive policies anyway, the utility of the initial authoritarian policies is unclear. The collateral damage of those policies, on the other hand, is visible everywhere.

Premature Conclusions

While Sweden states that its policy goal is to flatten the curve like most other countries, it's clear that they have taken a less aggressive approach. 

It follows that Sweden's virus curve should be steeper than the curve seen in lockdown jurisdictions. We can see this visually in the chart below (adapted from PBS):

(Since Sweden is taking some measures to slow the spread, it's likely that the relative steepness of their curve wouldn't be as radically different as what this graphic implies. But it does illustrate the nature of the difference we should expect.)

This presents a major challenge for gauging the success of the different approaches while the pandemic is still underway.

The total deaths experienced by the countries in the chart above would be found by taking the area underneath the curve. Because Sweden has accepted a steeper curve, it should experience more total deaths early on. But the number of new daily deaths in Sweden should also drop to near zero earlier than it will elsewhere.

That's what these curves would suggest, and it's consistent with what has actually happened.

Now we can see the problems with some of the condemnation and praise of Sweden's results. Yes, Sweden has experienced more deaths than many of its peers. And yes, for now, the pandemic in Sweden seems to be mostly over even as it rages on elsewhere. Neither of these outcomes should come as a surprise.

To consider the question settled right now is rather like declaring victory based on the score at halftime. It's not the end of the story.

Where We Go From Here

As I write this, the virus looks to be mostly contained in Europe, but continues to spread significantly in the US. Based on the data we have so far, it is unlikely that Sweden or any other large country has reached true herd immunity. Promising vaccine headlines get published regularly. But even in the most optimistic scenario, we're a few months away from a vaccine being proven safe and effective, let alone mass produced.

If current trends persist, the nationwide US per capita death toll is likely to catch and surpass Sweden in the coming months. In just the last two weeks, the gap between Sweden's death toll and the US's, has fallen from 30% higher to 19%. Virus cases have shot up in the most populous states (California, Texas, and Florida) that had been largely spared until this point. Increasingly, it looks like the US shutdown caused massive collateral damage without any lasting containment benefit. In a strictly US context, the Swedish approach is looking pretty good.

This conclusion is less obvious when looking at the results of countries in Asia, Europe, or the South Pacific. Countries like South Korea and Taiwan managed to slow the spread of COVID-19 with targeted quarantines instead of all-encompassing lockdown restrictions. Europe has several countries like Austria and Switzerland that locked down and then reopened quickly without reigniting a major new outbreak of the virus so far. In the South Pacific, New Zealand's more comprehensive lockdown and travel restrictions managed to eliminate COVID-19 locally, and a major new outbreak has not yet occurred.

It's too early to say which strategy will look optimal in the long run. The final analysis will also need to consider more holistic data points such as excess mortality and economic outcomes. That data isn't available in real-time like the official COVID-19 statistics, but it will be necessary to properly compare the costs and benefits across countries.

For now, Sweden's policy isn't a panacea or a disaster. It remains a crucial control group for the lockdown experiments of 2020.