Tag Archives: Nate Silver

Cases Climb, Most Patients Faring Better

30 Tuesday Jun 2020

Posted by in Pandemic, Public Health

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There’s been much speculation about whether recent increases in confirmed cases of COVID-19 (first chart above) will lead to a dramatic increase in fatalities (second chart). More generally, there is curiosity or perhaps hope as to whether the virus is not as dangerous to these new patients as it was early in the pandemic. I have discussed this point in several posts, most recently here. Based on the national data (above), we’re at the point at which an upturn in deaths might be expected. Based on the experience of many individual states, however, deaths should have trended upward by now, but they haven’t done so. Cases are generally less severe and are resolving more quickly.

Of course, more testing produces more cases (though there has been a mild uptick in test positivity over the past two weeks), but that doesn’t really explain the entire increase in cases over the past few weeks. In particular, why are so many new cases in the south? After all, there is evidence that the virus doesn’t survive well in warm, humid climates with more direct sunlight.

As I have mentioned several times, heavy use of air-conditioning in the south may have contributed to the increase. Nate Silver speculates that this is the case. The weather warmed up in late May and especially June, and many southerners retreated indoors where the air is cool, dry, and the virus thrives. Managers of public buildings should avoid blasting the AC, and you might do well to heed the same advice if you live with others in a busy household. In fact, nearly all transmission is likely occurring indoors, as has been the case throughout the pandemic. At the same time, however, with the early reopening of many southern states, younger people flocked to gyms, bars and other venues, largely abandoning any pretense of social distancing. So it’s possible that these effects have combined to produce the spike in new cases.

Some contend that the protests following George Floyd’s murder precipitated the jump in confirmed cases. Perhaps they played a role, but I’m somewhat skeptical. Yes, these could have become so-called super-spreader events; there are certain cities in which the jump in cases lagged the protests by a few weeks, such as Austin, Houston, and Miami, and where some cases were confirmed to be among those who protested. But if the protests contributed much to the jump, why hasn’t New York City seen a corresponding increase? Not only that, but the protests were outside, and the protests dissuaded many others from going out at all!

The trend in coronavirus fatalities remains more favorable, despite the increase in daily confirmed cases. One exception is New Jersey, which decided to reclassify 1,800 deaths as “probable” COVID deaths about six days ago. You can see the spike caused by that decision in the second chart above. Reclassifications like that arouse my suspicion, especially when federal hospital reimbursements are tied to COVID cases, and in view of this description from Bloomberg (my emphasis):

“… those whose negative test results were considered unreliable; who were linked to known outbreaks and showed symptoms; or whose death certificates strongly suggested a coronavirus link.”

Deaths necessarily lag new cases by anywhere from a few days to several weeks, depending on the stage at the time of diagnosis and delays in test results. The lag between diagnosis and death seems to center on about 12 – 14 days. Thus far, there doesn’t appear to be an upward shift in the trend of fatal cases, but the big updraft in cases nationally only started about two weeks ago. More on that below.

Importantly, a larger share of new cases is now among a younger age cohort, for whom the virus is much less threatening. The most vulnerable people are probably taking more precautions than early in the pandemic, and shocking as might seem, there is probably some buildup in immunity in the surviving nursing home population at this point. We are also better at treatment, and there is generally plenty of hospital capacity. And to the extent that the surge in new cases is concentrated in the south, fewer patients are likely to have Vitamin D deficiencies, which is increasingly mentioned as a contributor to the severity of coronavirus infections.

I decided to make some casual comparisons of new cases versus COVID deaths on a state-by-state basis, but I got a little carried away. Using the COVID Time Series web site, I started by checking some of the southern states with recent large increases in case counts. I ended up looking at 15 states in the south and west, and I added Missouri and Minnesota as well. I passed over a few others because their trends were basically flat. The 17 states all had upward trends in new cases over the past one to two months, or they had an increase in new cases more recently. However, only four of those states experienced any discernible increase in daily deaths over the corresponding time frames. These are Arizona, Arkansas, Tennessee, and Texas, and their increases are so modest they might be statistical noise.

Again, deaths tend to lag new cases by a couple of weeks, so the timing of the increase in case counts matters. Five of the states were trending upward beginning in May or even earlier, and 13 of the states saw an acceleration or a shift to an upward trend in new cases after Memorial Day, in late May or June. Of those 13, the changes in trend occurred between one and five weeks ago. Six states, including Texas, had a shift within the past two weeks. It’s probably too early to draw conclusions for those six states, but in general there is little to suggest that fatal cases will soar like they did early in the pandemic. Case fatality rates are likely to remain at much lower levels.

We’ll know much more within a week or two. It’s very encouraging that the upward trend in new cases hasn’t resulted in more deaths thus far, especially at the state level, as many states have had case counts drift upward for over a month. If it’s going to occur, it should be well underway within a week or so. Much also depends on whether new cases continue to climb in July, in which case we’ll be waiting in trepidation for whether more deaths transpire.

Covid Framing #6: The Great Over-Reaction

16 Saturday May 2020

Posted by in Pandemic

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I visited my doctor last Wednesday. He’s a specialist but also serves as my primary care physician, and we share the same condition. He’s affiliated with a prestigious medical school and practices on the campus of a large research hospital. First thing, I asked him, “So what do you think of all this?” Without hesitation, he said he believes we’re witnessing the single greatest over-reaction in all of medical history. He elaborated at length, which I very much appreciated, and I was gratified that much of what he said was familiar to me and my readers. The risks of the coronavirus are highly concentrated among the elderly and the already-sick, and the damage that the panic and lockdowns have done to the delivery of other medical care is probably a bigger tragedy, to say nothing of the economic damage. Furthermore, the Covid-19 pandemic is certainly not more threatening than others the world has experienced since WW II.

But did we know all that in March? No one with any sense believed the low numbers coming out of China; major flip-flops and mistakes by public health officials in the U.S. did much to confuse matters and delay evaluation of the outbreak. Nevertheless, there were reasons to proceed more deliberately. The explosion of cases in Italy and elsewhere consistently indicated that risk was concentrated among the elderly, so a targeted approach to protecting the vulnerable would have made sense. Still, individuals took voluntary action to social distance even before governments initiated broad lockdowns.

The lockdowns, of course, were sold as a short-term effort to “flatten the curve” so that medical resources would not be overwhelmed. There was, no doubt, great stress on front-line health care workers in March and April, and there were short-term shortages of personal protective equipment as well as ventilators for the most severe cases (but it’s possible ventilators actually harmed some patients). But whether you credit government action, private action, or the fact that so much of the population was not susceptible to begin with, mission accomplished! The strains were concentrated in certain geographic regions, especially the New York City metro area, but even there, the virus is on the wane. There is always the possibility of a major second wave, but perhaps it can be handled more intelligently by the public and especially public servants.

And now for some charts. Due to day-to-day volatility, and because the data on case numbers and deaths fluctuate on a weekly frequency, the charts below are on a 7-day moving average basis. It’s clear that the peak in U.S. daily confirmed cases was over five weeks ago, while the peak in Covid-attributed deaths was about three weeks ago.

Unfortunately, there is more doubt than ever about the legitimacy of the numbers. New York keeps “discovering” new deaths in nursing homes, a situation aggravated by a statewide order in March prohibiting homes from rejecting new or returning patients with active infections. There are reports from across the country of family deaths that were imminent, yet officially attributed to Covid. In one case, a death from severe alcohol poisoning was attributed to Covid. Colorado announced today that it was revising its death toll downward by about 24%.

The data on confirmed cases are elevated because testing keeps expanding. The first chart below shows that the number of daily tests has more than doubled over the past 3½ weeks. At the same time, the second chart below shows that the rate of “positives” has declined steadily for over six weeks. That is likely due to a combination of expanded testing for screening purposes, as opposed to testing mainly individuals presenting symptoms, and fewer individuals presenting symptoms each day.

As Nate Silver said on Saturday:

“There are still *way* too many stories about big spikes in cases when the cause of those spikes was a big increase in tests. And remember, it’s a good thing when states start doing more tests!”

One commenter on Silver’s thread pointed out that more testing is likely to lead to more confirmed cases even if the true number of infections is declining.

I’ll highlight just a few individual states. Missouri’s peak in cases appears to have occurred several weeks ago, though a spike at the end of April interrupted the trend. The spike was partly attributable to a flare-up at a single meat-packing plant (facilities that are particularly conducive to viral spread due to close conditions and aerosols).

Here is Georgia, which began to reopen its economy on April 24. The pro-lockdown crowd confidently predicted the reopening would lead to a spike in cases within two weeks. Georgia is conservative in its reporting, so they don’t extend the lines in the chart beyond 14 days of the most recent reports due to potential revisions. Nevertheless, it’s clear that the trend in cases is downward.

The pro-lockdown contingent predicted the same for Florida, but that has not been the case:

The next chart shows seven-day moving averages of deaths per million of population for four states: CA, FL, GA, and MO. The labels on the right might be hard to read, but MO is the green line. Deaths lag cases by a few weeks, and Missouri’s death rate was elevated more recently, again owing partly to the meat-packing plant. These death rates are all fairly low relative to the northeastern states around New York.

Finally, here are death rates per million of population for a few selected countries: Italy, Germany, Sweden, and the US. Italy had the large early spike, while Germany lagged and with a much lower fatality rate. The U.S. suffered more than twice the German death rate. Sweden, which has pursued a herd immunity strategy, has come in somewhat higher. The Italian and Swedish experiences both reflect high deaths in nursing homes, which might indicate a lack of preparedness at those institutions.

Here is a post from just a few days ago with a nice collection of charts for various countries.

Returning to the main gist of this “framing”, the Great Over-Reaction, the predictions setting off this panic were made by a forecaster, Neil Ferguson, who has had a rather poor track record of predicting the severity of earlier pandemics. The model he used is said to have been poorly coded and documented, and it is underdetermined such that many multiple forecast paths are possible. That means the choice of a “forecast” path is arbitrary.

Make no mistake: Covid-19 is a serious virus. Ultimately, however, the Covid-19 pandemic might not reach the scale of a typical global flu: the current global death toll is only about two-thirds of the average flu season (global deaths from Covid-19 are now about 312,000—the chart below is a few days old). In the U.S., the death toll is modestly higher than the average flu season, but that is largely attributable to the New York City metro area. Worldwide, Covid19 deaths are now about 30% of the toll of the Hong Kong flu in 1969-70, 28% of the Asian flu in 1957-58, and far less than 1% of the Spanish flu at the end of WW I. Neither the Hong Kong flu nor the Asian flu were dealt with via widespread non-prescription health interventions like the draconian lockdowns instituted this time. The damage to the economy has been massive and unjustifiable, and the effective moratorium on medical care for other serious conditions is inflicting a large toll of its own.

Again, we can identify distinct groups that are highly vulnerable to Covid-19: the aged and individuals with co-morbidities most common among the aged. A large share of the population is not susceptible, including children and the vast bulk of the work force. The sensible approach is to target vulnerable groups for protection while minimizing interference with the liberties of those capable of taking care of themselves, especially their freedom to weigh risks. Nevertheless, those facing low risks should continue to practice extra-good manners…. er, social distancing, to avoid subjecting others to undue risk. Don’t be a close talker, don’t go out if you feel at all out of sorts, and cover your sneezes!

Mass Shootings and Mass Manipulation

21 Wednesday Aug 2019

Posted by in Gun Control, Second Amendment

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The drumbeat for gun control from Leftist authoritarians never stops, and the recent mass shootings in Dayton OH, El Paso TX, and Gilroy CA, have been greeted with so much political agitation that the victims have become mere footnotes. Attempting to marshal facts in this debate can be quite confusing due to the variety of definitions of “mass shootings”. This variety contributes to certain myths about guns and gun violence that are often repeated by the media to a brow-beaten public. The confusion also motivates anti-gun policy prescriptions that are likely to be ineffective at best, and in all likelihood, counter-productive.

What constitutes a “mass shooting”? The traditional FBI definition counted an incident as a mass killling if four or more people were killed, not including the perpetrator. Broader definitions include cases in which 4 or more people are killed or injured, including the perpetrator. Gun rights opponents seem to prefer expansive definitions, including those that count gang-related killings, domestic shootings, or those occurring in the commission of another criminal act. Criminologist John Lott contends that these kinds of killings are driven by fundamentally different social forces than the mass public shootings that are at the center of this debate. For example, with respect to gang killings, Lott says:

“... the causes and solutions to drug gang violence are dramatically different than for the vast majority of mass public shootings, where attacks are designed to kill or wound as many people as possible. Padding the numbers by lumping the two together doesn’t make much sense.”

The more expansive definitions give rise to the notion that mass shootings have been trending-up dramatically in America. In fact, as Christopher J. Ferguson reports, data from The USA TODAY/AP/Northeastern University mass killings database show that the rate of mass shooting incidents per year has been flat since the early 1990s and are not much higher than the averages of the 1970s.

Another prominent distortion often accepted uncritically is that the U.S. leads the world in mass shootings. The U.S. totals are often inflated, but part of the reason for this misperception is that it’s easy to undercount foreign mass shootings. They do not always receive the same intensity of news coverage as mass shootings in the U.S., and tracking reports published in other languages is inherently more difficult for researchers. Lott says the following:

“Of the 86 countries where we have identified mass public shootings, the US ranks 56th per capita in its rate of attacks and 61st in mass public shooting murder rate. Norway, Finland, Switzerland and Russia all have at least 45 percent higher rates of murder from mass public shootings than the United States.”

The tragic nature of mass shootings should not prevent us from keeping the magnitude of these events in perspective, as Chris Buskirk explains in “Everything They’re Telling You About Mass Shootings Is Wrong“. For example, almost three-quarters of U.S. mass shootings in 2018 (four or more killed or injured) were associated with criminal activity, bar fights, and the like. And of course other social problems dwarf public mass shootings, such as the 70,000 opioid deaths that occurred in 2018, a phenomenon not coincidentally associated with the War on Drugs. And as Buskirk reminds us, the number of fatalities in public mass shootings is infinitesimal relative to the total number of defensive gun uses.

The Left’s reaction to these events is wrongheaded and their policy prescriptions are dangerous. A simple example is the widespread designation of buildings and public spaces as “gun-free zones”. However, it is highly likely that ending these designations would be an effective preventative against mass public shootings. John Lott writes in “How gun-free zones invite mass shootings” that 98% of the mass public shootings since 1950 occurred in areas where guns were prohibited. And we know that mass shootings are indeed prevented by armed citizens. Yet the Left staunchly opposes such a change and promotes the futile and foolish elimination of gun rights in general (also see this).

Leah Libresco, a statistician and former news writer at Nate Silver’s FiveThirtyEight, was highly disillusioned after devoting considerable effort to researching gun deaths. She expected to find that broad gun control measures were the answer. Instead, she says:

“… the case for the policies I’d lobbied for crumbled when I examined the evidence. The best ideas left standing were narrowly tailored interventions to protect subtypes of potential victims, not broad attempts to limit the lethality of guns. 

I researched the strictly tightened gun laws in Britain and Australia and concluded that they didn’t prove much about what America’s policy should be. Neither nation experienced drops in mass shootings or other gun related-crime that could be attributed to their buybacks and bans.”

Then there are the continuing, uninformed calls to ban “assault weapons”. As Libresco explains:

 “… no gunowner walks into the store to buy an ‘assault weapon.’ It’s an invented classification that includes any semi-automatic that has two or more features, such as a bayonet mount, arocket-propelled grenade-launcher mount, a folding stock or a pistol grip. But guns are modular, and any hobbyist can easily add these features at home, just as if they were snapping together Legos.”

Bill Clinton weighed into the debate last week by claiming that his assault weapons “ban”, which began in 1994, was so effective that we should be eager to accede to plans recently put forward by Democrats. Mark Overstreet quickly called him out as a liar, and on no less than six counts. Not only were existing “assault weapons” exempted under Clinton’s “ban”, but Americans actually added to their private stocks of weapons that met the law’s criteria during its enforcement. Existing large ammunition magazines were exempted, as well as imports of such magazines. Thus, Clinton’s so-called ban did not even approach the draconian measures now being proposed, which range from manufacturing and import prohibitions all the way up to confiscation.

Also preposterous are the Left’s routine characterizations of mass shooters as “right-wing extremists”. The truth is hardly clear cut. For example, despite expressing strong anti-immigrant sentiment, the shooters in El Paso and Christchurch, New Zealand were both environmental radicals or “eco-fascists”, in the Christchurch shooter’s words. The Dayton shooter was a self-described socialist and a supporter of Bernie Sanders, as was James T. Hodgkinson, the gunman who attacked a group of Republican legislators at a baseball practice, seriously injuring Congressman Steve Scalese. These madmen clearly weren’t crazed right-wing zealots. If anything, their profiles usually reflect severe psychological as well as ideological confusion.

Even one public mass shooting is too many, but their prevalence in the U.S. has been exaggerated in several ways. The hyperbole is often politically-motivated, intended to create negative public sentiment toward Second Amendment rights. But you can’t stop public mass shootings by foolishly disarming or criminalizing the very law-abiding citizens who are often the only force capable of providing an immediate defensive response.