Stop saying “variance-covariance matrix.” It’s just “covariance matrix.”
A covariance matrix is a symmetric matrix in which each element i,j = covariance(Xi, Xj), where Xi is a random variable. By definition the diagonal elements i,i = covariance(Xi, Xi) ≡ variance(Xi). That is always true of a covariance matrix, so there is no need to (re-)state that. I.e., adding the prefix “variance-” to the term “covariance matrix” never adds information. Except, perhaps, to suggest that the speaker does not fully understand this.
(I’ve heard some suggest that referring to it as a “variance-covariance” matrix helpfully reminds people that the diagonal is the variance of each variable. But if the reader or writer doesn’t already understand that then they’re not going to get very far with the topic.)
Arming cops is worse than arming average citizens because private citizens face both civil and criminal liability for using force. Even a fully justified use of force can send a citizen through the ordeal of arrest, jail, and a criminal trial. It is hard to overstate the consequences of being put through the criminal justice system: A public arrest cannot be expunged from the internet. There is no compensation for the financial damage of being jailed, or the costs and curtailment of rights that accompany posting bail for the months or years it takes to get a trial. Legal fees to defend oneself in court cannot be recovered even if one is vindicated. These severe consequences deter people from unjustified acts of violence.
In contrast, thanks to qualified immunity, American police face no civil liability for misuse of force. In theory police face criminal liability for unjustified violence, but in practice this risk is also negligible: Police are not immediately arrested for acts of violence. Instead police officers are given paid vacation and public anonymity while their union lobbies their colleagues in law enforcement against filing criminal charges, and their brothers in blue pick over evidence to justify their behavior and publicly vilify their victims.
The public is supposed to believe that law enforcement agencies are competent to investigate and correct their members for acts of abuse. But those administrative trials are conducted in secret, and their results are almost always kept confidential. The most serious adverse consequence is for an officer to (eventually) lose his job and have to find one with a different law enforcement agency.
This asymmetry in process and consequences is too extreme: Justified use of force by a private citizen can cost them years of time, hundreds of thousands of dollars, and can haunt them forever. Unjustified use of force by a cop can cost … maybe having to find another job.
I can see two obvious ways to restore some balance here:
Require that every use of force incident be presented to a grand jury but don’t let the jury know whether the suspect is a cop.
Send every use of force incident to a prosecutor that is independent of mainstream law enforcement: i.e., a prosecutor who does not otherwise depend on the cooperation of police to conduct his job.
Hold cops to the same criminal standards as other citizens who use lethal force. Or don’t give them lethal weapons.
Does it feel like the free online services keep getting worse, not better? You’re not imagining it. It’s all part of the business Circle of Life. Great read today details this: After accruing a vast audience by subsidizing user experience, there are irresistible incentives for companies to “monetize” by degrading the user experience “… to the precise threshold at which users are nearly pissed off enough to leave, but not quite.”
For over 25 years I have used Mitchum Unscented Gel Antiperspirant. Last month I started a new tube and was irritated by a significant perfume-like scent. Did they mess up a batch? I wrote them and they responded:
The Mitchum deodorant range has implemented a formula change in order to improve performance. This minor formula change includes the addition of a ‘masking agent’ to neutralise scent in the new formula and to ensure that Mitchum Unscented will continue to have no noticeable smell.
<Facepalm>. Not only does the formula change have a very noticeable smell, but it also feels sticky where the previous formula did not. I’m not the only consumer to notice.
Why do companies ruin popular products under the guise of “improvement?” Do they have too many managers with nothing to do? This reminds me of another episode: When I was at boarding school I, like the majority of boys, used a “shampoo + conditioner in one” called Pert Plus. The light green bottles were ubiquitous in the showers. Then the company “improved” Pert Plus with a formula that was relatively watery and had a stronger smell. Before long everyone was using other products. I was annoyed that I had to find a new shampoo.
Last month I discovered that Google broke their Drive cloud storage service: it will no longer mirror files on local storage. I’m not going to put my important data in the cloud if there’s no way for me to access it when I don’t have cloud connectivity. And it’s not like mirroring is a big ask: This is a basic feature of cloud backup going back many years. Google Drive did it for years, and Microsoft OneDrive (my primary cloud backup) still does it reliably.
So what does Google do? Instead of fixing this essential feature, today they sent out an Email inviting us to buy more cloud storage. And that’s not all! Following the classic infomercial strategy Google extends this offer: Subscribe to 2TB of Google storage (for $100/year) and they’ll send you a free Google Nest Hub device (which they otherwise sell for $100)!
In some ways it feels like technology is taking us backwards. At the turn of the century Tivo freed us not only from having to sit for our favorite shows at fixed times, but also from having to sit through commercials. Now streaming services have begun to pepper video content with commercials that we can’t skip. And I’ve noticed something strange about the latest generation of these advertisements: People of pallor are startlingly underrepresented. Not that I object to that. I do find it to be an amusingly patronizing reversal of, say, the olde old days of theater when virtually every character, regardless of race or gender, was played by a male. It is also a little uncanny: Like when a white person shows up in a commercial I wonder, “What happened – couldn’t the casting director find a person of color? Is that even legal?”
I’ve taken an interest in the latest diffusion “artificial intelligence” image-generation systems. And the lengths to which their development organizations go to prevent them from doing anything politically incorrect is … Orwellian.
Reducing bias: We implemented a new technique so that DALL·E generates images of people that more accurately reflect the diversity of the world’s population. This technique is applied at the system level when DALL·E is given a prompt about an individual that does not specify race or gender, like “CEO.”
Imagen relies on text encoders trained on uncurated web-scale data, and thus inherits the social biases and limitations of large language models. As such, there is a risk that Imagen has encoded harmful stereotypes and representations, which guides our decision to not release Imagen for public use without further safeguards in place.
“Like what harmful stereotypes?” you may wonder. Well, there is “an overall bias towards generating images of people with lighter skin tones and a tendency for images portraying different professions to align with Western gender stereotypes.” Can you imagine the damage if the general public had uncensored access to an information system that contained biases in its depiction of skin tone and gender?
What norms of institutional behavior today will be considered crude and barbaric in the future? I hope that among them will be found: methods of criminal law enforcement, and the broad license granted to its officers to harass and assault people and property, as seen in today’s United States. The idea that some people (e.g., American cops) should be given authority and immunity from consequence, to use whatever force they deem appropriate to physically subdue and detain any person on virtually any pretext; should eventually be considered as barbaric as the Old convention that it was permissible for soldiers to rape, pillage, and murder civilians. This is not to say that evolving more civilized standards of behavior is easy (which is one of the themes explored in the review linked above): As long as people have the ability to transgress boundaries by force, people will also need to use (or at least threaten to use) force to constrain transgressions. The hard part is in constraining the permissible use of force. One might say that devising norms and institutions of constraint that minimize the use of force is the evolving project of civilization.
(Note that an ultimate civilization is not one that exercises no force. Any such organization would fall prey to competitors that do use force. Civilization is maximized when it minimizes the amount and nature of force employed to sustain itself.)
Continuing this previous post: I will explain why if police do their job properly they should never have to fire a gun at anyone or anything.
American cops need guns because Americans have so many guns. Or so goes one of the arguments for equipping virtually all law enforcement officers in the United States with handguns. Is it reasonable and necessary to add handguns to the hip arsenal of a “peace” officer that already includes lights, handcuffs, pepper spray, taser, automatic knife, and a baton? (Note that the latter two are already classified as lethal weapons and often illegal for private citizens to possess.)
Typical American police duty belt, offering immediate access to radio, flashlight, handcuffs, pepper spray, baton, taser, and handgun.
Perhaps you have absorbed the Hollywood “hot-pursuit” trope in which cops corner a suspect who turns a gun on them, leaving the police with no choice but to kill or be killed. In reality: Policing need not and should not be conducted via Western-style quick-draw showdown.
In the old days you couldn’t radio for backup. But you could still take cover.
Police are not superheroes or world-class athletes. Cops do not battle with criminals on a level field – in terms of numbers, weapons, or tactics. The most powerful police tool is not a weapon, but a radio. Facing a dangerous situation a single cop can summon a battalion of law enforcement personnel and virtually unlimited resources. Police can create a safe perimeter around anyone they consider a danger. No matter how armed or dangerous the suspect, none of the police need to carry firearms: They can wait behind their cars and bulletproof shields, in shifts if necessary, to outlast anyone who defies their orders.
Police response to a single unarmed drunk man resisting arrest.
Nor should police use lethal force to try to stop fleeing suspects. Police can afford to track a suspect indefinitely and wait until they have the advantage to effect a minimal-risk arrest. Police can marshal not only the vast resources of the government, but even the assistance of the general public. Cases in which a dangerous fugitive evades capture for any amount of time are so rare that they make national news.
The number of firearms in the United States does not correlate to the risks that police face. For one thing: Criminals in countries with few firearms still acquire and use guns. Police in all countries are prepared to handle armed suspects, regardless of how many or few guns are in circulation. But private gun ownership is a red herring: Police everywhere have to confront suspects armed with other common lethal weapons, including vehicles and knives. Even American police recognize that a person closer than seven yards carrying an edged weapon poses as grave a threat as a person brandishing a firearm.1
Police in other countries are able to keep the peace without routinely shooting citizens, and in fact often without carrying firearms at all. There’s no mystery in this: good cops everywhere follow their training to contain and deescalate. But in America police have also been given military tools and tactics: not just firearms, but also broad discretion and vast immunity from liability in the use of lethal force – something more appropriate to a war zone. And, not surprisingly, American policing has attracted and bred cops with a propensity for using violence instead of less lethal tools and tactics.
I don’t have an answer to the headline question. But I do have some reasons that people should stick with credit cards that offer spending rewards in currency (a.k.a. “cashback”) instead of points.
What the heck are points?
“Points” are what you give children for good behavior. Or what you use to score games. They are not fungible, but they are definitely fudgeable. Points can be taken away for bad play. And their value is subject to the whim of whomever creates them. Did your children find a way to game your points system? Did your spouse create point hyperinflation to stop the kids from nagging? No problem: Just devalue the points! How many points for another smartphone app? Was it 100 before? Oops, that was a limited promotion. Now apps cost 200 points.
Surely banks would not play so fast and loose with points … right? Well let’s see. There are three problems with points: Value, Liquidity, and ownership.
Liquidity and ownership: What does it take to redeem points? Transfer them? I have seen points programs that allow transfers to other people in the program, but the fine print has a large minimum (e.g., 5,000 points) for any transfer, as well as a substantial transfer fee (e.g., $25). You may think you have $49 worth of points. But if you can’t redeem or transfer those points, they’re not worth anything like $49 of currency.
Value: But at least a point is worth US$.01, right? Or its value is contractual and immutable? No! The real value of loyalty program points is dependent on so many factors that The Points Guy website attempts a periodic valuation that is quite subjective:
These valuations are based on a combination of what I would pay to buy points if given the opportunity and the overall value I could get from redeeming them, factoring in variables like award availability, fees and change/cancellation policies.
Value to the points program owners is somewhat less subjective: During the 2020 crisis the United Airlines tried to tap some of that value, and the Wall Street Journal explained:
Loyalty programs are a rich vein for airlines to secure cash. … United said its MileagePlus program generates over $5 billion in cash a year and is worth over $20 billion.
The program earns most of its revenue selling miles to third parties such as JPMorgan Chase, its credit-card provider, which then awards them to customers for making purchases.
United said it expects fewer people to redeem their miles for travel due to the pandemic, which means more money stays within the loyalty program. But loyalty programs could take a hit if customers begin to question the value of accruing travel perks they don’t plan to use anytime soon or if a weaker economy reduces spending overall.
The fact that points generate so much profit for the program owners suggests that the points themselves are worth less than consumers might think.
In a purely federal system, in which governmental functions were clearly differentiated between the national and state governments, federalism would not translate directly into complexity. But that is not American federalism as it is currently practiced. “Our federalism” creates a bias toward sending money to the states, even though the cash always comes with a laundry list of regulations and requirements attached.
One of the clearest findings in the study of American public opinion is that Americans are ideological conservatives and operational liberals. That is, they want to believe in the myth of small government while demanding that government address public needs and wants regarding everything from poverty and retirement security to environmental protection and social mobility.
This ambivalence in expectations creates a durable bias in the actual outputs of American government. The easiest way to satisfy both halves of the American political mind is to create programs that hide the hand of government, whether it is through tax preferences, regulation, or litigation, rather than operating through the more transparent means of direct taxing and spending.
Effective January 2021, DoT ruled that air passengers can no longer bring arbitrary pets on commercial flights by claiming them as “Emotional Support Animals.” They can, however, bring up to two dogs on board if the passengers claim the dogs are “Psychiatric Service Animals.” All the passenger has to do is fill out this single-page form. There is no independent verification of the claim that either (a) the passenger has a disability or (b) the dog has specific training to assist with a disability.
I’ve also been reading Theodore Dalrymple’s book Life at the Bottom. A striking sociologic survey of the endemic pathological behaviors by which people mire themselves in misery, as well as the policies and institutions that keep them there. #EssentialReading
Detailed here: Now six months after the “Capitol Riot,” the U.S. Capitol Police (USCP) have not even released the name of the plain-clothes officer who shot and killed an unarmed female protester. (His was the only round fired by anyone during the four-hour melee.)
The name of the officer (USCP Lieutenant Michael Byrd) was accidentally mentioned, and recently discovered, in a recording of a hearing on the Capitol Riot. Armed with his name, he has been identified in other footage from that day. Here is a photo in which he can be seen with his finger on the trigger of his pistol:
If regular citizens were caught with a finger inside the trigger guard of a firearm when they were not justified in shooting, they would almost certainly be charged with crimes, starting with felony reckless endangerment. In this case, the reckless cop subsequently killed someone but has since enjoyed over six months of official anonymity, protection, and paid vacation (“administrative leave”).
If you don’t resist, cops can provoke you to resist.
This innocent man was assaulted by cops who claim to have mistaken him for another person with an open arrest warrant. Although he is clearly trying to comply with their chaotic commands, one of the cops shoots him in the back with a taser. The man flinches but the taser malfunctions. The cop then jump-kicks the man in the back. The man turns in disbelief and then is tackled by three deputies, who subsequently charge the innocent man with “resisting arrest.” (See details and more of the video, recorded by the man’s sister before another deputy assaults her.)
Months later the Sheriff released the following statement regarding the incident:
The Sheriff’s Office conducted an administrative investigation, the allegations were sustained against the deputy, and appropriate action has been taken. Specifics regarding discipline are part of a peace officer’s confidential personnel file, which we are prevented from disclosing under the law.
Accountability? We have nothing but the Sheriff’s word that “appropriate action was taken.” When? By whom? And what did it consist of? For all we know the cop who attacked and provoked the peaceful citizen got a pat on the back.
Deputies are often forced to make split-second decisions. Second-guessing those decisions, especially when the facts are still unclear, is dangerous and unfair.
Guess what happens when a regular citizen produces a gun for self-defense – even without killing anyone? Arrested and held (without pay) in jail. Further, at the whim of local prosecutors: Often held for criminal trial, which can personally cost the citizen many tens of thousands of dollars to defend and put their life on hold for years. In contrast: Cops enjoy broad (“qualified“) legal immunity, plus customary exemption from arrest and criminal charges by other law enforcement officers (including prosecutors). When a cop is tried for violating another citizen’s civil rights, the cop’s civil defense – and any judgment – is billed to taxpayers. The cop’s union ensures that he loses neither wage nor public pension.
* Leaving aside the obvious question of whether it’s “fair” to kill a 17-year-old boy.
I wasn’t surprised to see Amazon roll back its mandatory arbitration clauses – they are actually quite beneficial to consumers with who can advance their own small claims: The companies who impose the clauses have to pay the arbitration fees, which can run into four figures, as well as lawyers to deal with them. A few years ago I caught Verizon’s FIOS service failing to honor its own terms for customers who “purchase” online movies. I wrote them a letter threatening to take the matter to arbitration, and someone in their legal department quickly agreed to settle with me for a statement credit of $500. (I probably wouldn’t have bothered if I had to pay filing fees in either arbitration or court.)
There are heroes who happen to be cops. But being a cop does not make one a hero. The occasional acts of heroism that earn cops commendations are done by plenty of people who aren’t sworn and paid “to protect and serve.” Rushing into a dangerous situation to aid others? Gestures of kindness or compassion that go above and beyond the call of duty? All routinely done by everyday heroes.
Cops actually enjoy more protection than the average citizen:
Cops enjoy special legal protections: merely touching a police officer can constitute aggravated assault and is often its own crime.
Cops enjoy qualified immunity against acts of commission. Cops harass and arrest people with such impunity that their abuse of discretion goes by the common name “contempt of cop.” Victims of police abuse have no practical redress: Expensive and often fruitless civil lawsuits can only be filed against the government, not against the abusive officers.
Cops enjoy qualified immunity and substantial deference in using force against members of the public. Governments don’t reliably collect data on the use of force by police – not even the use of lethal force. Prosecutors are notoriously hesitant to bring criminal charges against their fellow law enforcement officers. The only redress available to victims of police violence are mostly futile civil lawsuits against the government.
Abusive cops are protected from adverse consequences by powerful police unions. Claims of police violence generally disappear into secret internal investigations that impose no apparent consequences on violent cops.
Bad cops may be a minority, but every law enforcement officer is morally responsible for shielding them. If cops were heroes they would not tolerate those in their midst who abuse the office and victimize the public.
Do you think cops need your thanks or support, in addition to the broad Blue Privileges they already enjoy? Take a look at what cops are paid. Of course this varies by jurisdiction, but it’s not hard to find cops raking in six-figure incomes while accumulating a similar government-guaranteed lifetime pension that pays out after as few as 20 years of “service.”
The Biden Administration is providing the biggest positive stimulus to demand since WWII, and at the same time doing everything it can to suppress supply. Higher [unemployment insurance] benefits, closed schools (which keep one parent at home), and promised corporate tax hikes practically guarantee that supply can not keep up with demand. It is a recipe for an inflation shock we have not seen in the U.S. in a generation.
Kevin Hassett
It has been a decade since I last wrote about inflation. Now the U.S. government and the Federal Reserve seem to be doing everything possible to spark dollar inflation.
What can you do to protect against inflation? Financial securities price in inflation faster than you can (e.g., TIPS give negative yields, commodity futures enter contango), so by the time “inflation” is in the news you can’t generally buy a direct, liquid, inflation hedge in the markets. Buying and holding useful commodities is a hedge against inflation. Real estate is a useful quasi-commodity. Unfortunately real estate prices are, if anything, leading inflation in the last year. But if you already own your primary residence there’s one thing you can and should do: Mortgage your home to the limit. The government actually subsidizes mortgages (offering credit guarantees for some, and offering a tax credit for mortgage interest). Mortgage loan rates are at historic lows – basically equal to inflation on an after-tax basis. And here’s the clincher: Mortgages are dollar-denominated debt – the one thing that comes out ahead in a dollar inflation scenario.
The other subsidized government investment is the inflation-protected I bond. It’s more of a savings vehicle, and I bond purchases are limited to $10,000 per year per person.
This article lays out overwhelming circumstantial evidence that SARS2 was created in and released from the Wuhan Institute of Virology. The level of incompetence that led to the outbreak is astonishing. As is the diligence of the political conspiracy to cover this up.
Researchers at the Wuhan lab were engaged in a project that explicitly involved modifying bat-based coronaviruses to infect the human respiratory tract. (SARS2 is a bat-based coronavirus that is optimized for infecting human respiratory cells.) The most unconscionable news is that this project was conducted in a BSL-2 lab! (As the article notes: BSL-2 is essentially the level of protection against infection practiced in a typical U.S. dental office. I previously derided the idea that Chinese could be relied upon to operate a BSL-4 facility, which is the only place where creation of new human pathogens should occur – if anywhere at all.)
The only obstacle to “proving” that SARS2 was produced in that lab is China’s impounding of the lab records.
As of this week virtually everybody in the United States who wanted a COVID vaccine has been able to obtain one.
And yet … governments and commercial establishments are still mandating that everyone wears a mask (or “face covering”). Apparently wearing a mask has turned into a sort of political statement – a sign of submission to arbitrary authority?
I found this study from 2015 that compared cloth masks to disposable surgical masks in hospital settings in which workers were exposed to influenza (that other deadly, contagious respiratory virus). The authors did not expect to find a difference in protection between the two mask materials. What they found was that subjects who diligently wore cloth masks ended up with higher infection rates than the control group or the subjects assigned to wear surgical masks.
Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.
MacIntyre, C Raina et al. “A cluster randomised trial of cloth masks compared with medical masks in healthcare workers.” BMJ open vol. 5,4 e006577. 22 Apr. 2015, doi:10.1136/bmjopen-2014-006577
Federalist 