Guderian was less interested in destroying the enemy than in forcing defenders to keep their heads down

June 28th, 2023

How Hitler Could Have Won World War II by Bevin AlexanderBefore the campaign to invade France started, Bevin Alexander explains, in How Hitler Could Have Won World War II, Guderian had worked out a plan of attack by the Luftwaffe:

Since few of his own artillery pieces could get to Sedan in the press of men, horses, and machines on the roads to the rear, Guderian intended to use Stukas as aerial artillery to help his infantry get across the river. He wanted a few aircraft to remain over Sedan before and during the crossing to make both actual and fake bombing and strafing runs on the French positions. Guderian was less interested in destroying the enemy than in forcing defenders to keep their heads down so his infantry could rush across the stream and find lodgment on the far side. This is what he had worked out with the Luftwaffe staff.

[…]

They used the tactics he had worked out beforehand: one group of Stukas bombed and machine-gunned trenches, pillboxes, and artillery positions (or pretended to do so), while a second group circled above, waiting to take over. Above these was a fighter shield.

[…]

The effects were remarkable. When the assault force, 1st Rifle Regiment, assembled on the river just west of Sedan, enemy artillery was alert and fired at the slightest movement. But the unending strikes and faked strikes by the aircraft virtually paralyzed the French. Artillerymen abandoned their guns, and machine-gunners kept their heads down and could not fire.

As a consequence 1st Rifle Regiment crossed the river in collapsible rubber boats with little loss and seized commanding heights on the south bank.

Purposefully doing things extremely wrong provides us with a lot more information

June 27th, 2023

In a recent study, Arizona State University professor Rob Gray trained casual baseball player to hit a baseball the right way or the wrong way:

One group — the “right way” group — practiced hitting the ball the correct way. Their instructions were to “hit a hard line drive into fair play.”

And during their training sessions, a coach would observe and give them feedback on their technique and mechanics. And provide suggestions on how to improve their performance.

The “wrong way” group on the other hand, received no technical instructions and no corrective feedback during their training sessions.

And their hitting instructions changed from one training session to the next.

One week they were asked to “hit the ball as far to the right as possible.” Another week they were asked to “hit the ball as far to the left as possible.” Then they were asked to “try to pop the ball up in the air.” And then to “try to drive the ball into the ground.”

They were also asked to “hit a hard line drive into fair play” in one of their practice sessions, just like the right way group. But in five of their six practice sessions, they were asked to practice hitting the ball all the wrong ways.

[…]

Well, as you would expect, the right way group that got coaching and practiced hitting into fair play improved their hitting in several key areas.

Their batting average improved, they struck out less often, and they hit more doubles/triples/home runs than they did in their initial test too.

But the wrong way group, which spent 5/6th of their time practicing hitting balls into foul territory, and other undesirable hits also improved their batting average, strikeout percentage, and slugging percentage.

And they not only improved in these areas, but improved by a lot more than the right way group did!

[…]

The value lies in learning how to achieve specific undesirable outcomes, on purpose, with some consistency. Because it seems that purposefully doing things extremely wrong provides us with a lot more information about how to do things correctly, than trying to do things correctly and accidentally getting it slightly wrong.

When I am weaker than you, I ask you for freedom because that is according to your principles

June 26th, 2023

Suicide of the West by James BurnhamI was recently listening to the audiobook version of James Burnham‘s Suicide of the West, when he quoted Louis Veuillot as saying, “When I am the weaker, I ask you for my freedom, because that is your principle. But when I am the stronger, I take away your freedom, because that is my principle.”

Naturally I immediately recognized the quote from Frank Herbert’s Children of Dune, in slightly different form: “When I am weaker than you, I ask you for freedom because that is according to your principles; when I am stronger than you, I take away your freedom because that is according to my principles.”

Centurions by Jean LarteguyIn fact, I also came across another version in Jean Lartéguy‘s The Centurions: “The liberty which you demand from us in the name of your principles, we deny you in the name of ours.”

It turns out Veuillot never said any of the three versions:

According to Pierre Pierrard, this was attributed to Veuillot by Montalambert, and Veuillot protested he did not say it.

A few things he did say:

Newspapers have become such a danger that it is necessary to create many. You cannot contend against the Press, except through its multitude. Add flood to flood, and let them drown one another, forming no more than a swamp, or, if you will, a sea. The swamp has its lagoons, the sea its moments of slumber. We will see whether it is possible to build some Venice within it.

When I voted, my equality tumbled into the box with my ballot; they disappeared together.

If I could re-establish a class of nobles, I should do so at once, and I would not belong to it.

Amongst the amusements of Paris must be counted duels between journalists.

The federal court decision affecting homeless tent encampments in America

June 25th, 2023

Five years ago, a federal court issued a crucial ruling, Martin v. Boise, affecting homeless tent encampments in America:

People experiencing homelessness, the Ninth Circuit Court of Appeals said, can’t be punished for sleeping outside on public property if there are no adequate alternatives available.

[…]

The case dates back to 2009, when Robert Martin and a group of fellow homeless residents in Boise, Idaho, sued, arguing that police citations they received for breaking local camping bans violated their constitutional rights. In 2018, the Ninth Circuit agreed that prosecuting people for sleeping or camping on public property when they have no home or shelter to go to violated the Eighth Amendment’s prohibition on cruel and unusual punishment.

“The government cannot criminalize indigent, homeless people for sleeping outdoors, on public property, on the false premise they had a choice in the matter,” the court declared.

States, cities, and counties urged the US Supreme Court to take up the case, arguing the Ninth Circuit had created “a de facto” right to live on sidewalks and in parks that would “cripple” local leaders’ ability to safely govern their communities. But in 2019, the court declined, baffling some experts, though others suspect it’s because there were no conflicting circuit decisions at the time.

[…]

While the decision only formally applies in areas under the Ninth Circuit’s jurisdiction, the ruling has reverberated nationally, as local governments consider how to address unsheltered homelessness in ways that could avoid costly constitutional legal battles. There have already been dozens of court cases citing Martin, including in the Fourth Circuit in Virginia, and federal lower courts in Ohio, Missouri, Florida, Texas, New York, and Hawaii.

For now, though, Martin’s impact can be seen most clearly out West. Just before Christmas 2022, for example, a district judge cited Martin when she ruled that San Francisco can no longer enforce encampment sweeps — meaning clear out homeless individuals and their property from an outdoor area — since the city lacks enough shelter beds for those experiencing homelessness to move into. San Francisco appealed the decision, arguing it’s “unnecessarily broad and has put the City in an impossible situation.”

In Phoenix, Arizona, residents and business owners filed a lawsuit last summer against the city for allowing a downtown homeless encampment to grow with nearly 1,000 people, but a federal judge — echoing Martin — barred Phoenix in December from conducting sweeps if there are more homeless people than shelter beds available. A competing decision issued in March by a state judge ordered Phoenix officials to clean up the “public nuisance” at the encampment by July 10, arguing the city has “erroneously” applied Martin to date.

The goal of productive failure is not to get the correct answer faster and more easily via shallower learning

June 24th, 2023

Early floundering can lead to better learning:

Generally, teaching looks something like:

  1. Explain how to do something (lecture)
  2. Show students what it looks like in action (demonstration)
  3. Fix their off-target attempts, to help them minimize “failure,” and reward them for their successes (feedback)

This sequence tends to emphasize getting to the correct answer as expeditiously as possible.

[…]

A pair of researchers (Kapur & Bielaczyc, 2011) conducted a study of “productive failure” to see if early floundering would lead to better learning than the traditional teaching approach (“direct instruction”).

[…]

The direct instruction class began learning about average speed with a lecture.

The teacher explained the concepts, worked through some examples, encouraged questions, and had students solve practice problems.

Then they reviewed the problems and discussed the solutions.

For homework, they were assigned similar problems in their workbook.

[…]

The productive failure class was split up into small groups, and each was tasked with solving two complex problems…

They were given these problems with no teacher support or guidance, but simply allowed two class periods to try to solve each problem (4 classes total).

There was also no homework, though they did receive extra problems to work on individually when the group problems were complete (2 class periods).

After 6 sessions of working on their own, the class spent their final class session sharing their solutions and strategies with the teacher and each other.

Only then did the teacher finally explain how to solve these problems the “correct” way, and help the students go through their previous work, fix their mistakes, and ensure they could arrive at the correct answer.

Ultimately, the productive failure group spent 7 class sessions working on calculating average speed, just like the direct instruction group. But they spent most of these classes floundering on their own, and doing many things wrong. It was only during the 7th and final class that they learned the correct way to approach these problems.

[…]

As you can probably imagine, the direct instruction group did waaaay better than the productive failure group in the early stages of learning.

The direct instruction group averaged a score of 91.4% on their homework.

Meanwhile, the productive failure group performed miserably on their unguided attempts to solve the complex problems. Only 2 out of the 12 groups (16%) arrived at the correct solutions. And when they had to work on the problems individually, their average score of 11.5% was even worse.

But a very different picture emerges when you look at the groups’ performance on the post-test.

On the final test, the performance between the two groups flipped, and the productive failure group outscored the direct instruction group by a significant margin.

On the simple problems, the productive failure group earned an average score of 84.8% (vs. 75.3% for the direct instruction group).

And on the complex problem, the productive failure group earned an average score of 59.7% (vs. 42.4% for the direct instruction group).

[…]

However, in much the way that spaced, random, and variable practice lead to worse performance in the short term, but better performance in the long term, it seems that the goal of productive failure is not to get the correct answer faster and more easily via shallower learning (“unproductive success”), but instead, to cultivate a deeper understanding of the fundamental principles and various ways of arriving at a solution even at the expense of short-term performance.

For more effective practice, try…longer…pauses

June 23rd, 2023

For more effective practice, try…longer…pauses:

Several researchers have looked at something known as the “inter-trial interval” or “post-KR delay” (KR stands for Knowledge of Results). This is the amount of time that elapses between one practice attempt and the next. For instance, if you’re practicing a tricky shift, you could just execute the shift over and over with no pauses between attempts. Or, you could try the shift, pause, and then try again. That pause between attempts is the inter-trial interval.

Thinking back, I’m not sure I ever made time for even the slightest pause between practice attempts when I was a kid. I totally piñata’d my way through every practice session. Heck, even in lessons I’d often cut my teachers off while they were still talking in a rush to play the passage again and get it right.

I always assumed that learning happened during the time my muscles were moving. The idea that some of the learning might take place in the time between practice attempts never occurred to me.

[…]

A 2005 study (Bock et al.) in the journal Experimental Brain Research yields a few clues.

35 participants were split up into six groups, and given one practice session (and 25 practice attempts) to learn a tricky motor task.

The only difference between groups was the amount of time each was given between practice attempts. One group received a 1 second pause between attempts, while the others were given either 5, 10, 15, 20, or 40 seconds.

[…]

Everyone improved with practice, but the participants who received only a 1-second pause between practice attempts consistently performed worse than the others, and weren’t as accurate in their efforts to hit the target.

[…]

A 2007 study (Huang & Shadmehrin) in the Journal of Neurophysiology also reported on this phenomenon.

[…]

Anyhow, the researchers in this study replicated the findings of the other study, observing that the longer delay of 14 seconds between practice attempts led to more rapid improvements than a shorter 4-second delay.

[…]

Take your time between repetitions. Pause. And don’t just count to five or 7 or 11, but use that time to ponder or reflect on what just happened, and why it happened. Plan your next move. Give it a go.

Hydrogen fuel cells have found their groove

June 22nd, 2023

Hydrogen fuel cells have found their groove, IEEE Spectrum reports:

Now scientists have found that adding grooves to PEM fuel cells can improve the performance of these devices by up to 50 percent compared with state-of-the-art conventional electrodes under standard operating conditions.

[…]

Conventional PEM fuel cell electrodes are composed of a carbon-supported platinum catalyst and ion-conducting polymers known as ionomers, which are mixed in an ink slurry and deposited on a membrane or other structure as a porous electrode. This creates a random electrode structure with a complex, mazelike network of narrow pores that limits the flow within the fuel cell. This structure has largely stayed the same for more than 30 years, the researchers note.

In contrast, the new electrodes feature catalyst ridges loaded with ionomers separated by empty grooves. The ridges improve proton transport, while the grooves simultaneously help oxygen flow.

In conventional PEM fuel cell electrodes, a high ionomer content may enhance proton transport, but it typically also limits oxygen flow. By separating proton and oxygen flow along grooves and ridges, the new electrodes help improve the transport of both. This also helps keep reaction rates uniform in the fuel cell, boosting catalyst performance.

The scientists fabricated the new electrodes by depositing a mixture of carbon-supported platinum catalyst and ionomer in a patterned silicon template, followed by a transfer to a membrane made of the common polymer electrolyte known as Nafion. They experimented with electrodes with grooves 1 to 2 micrometers wide, and had grooves repeat across the electrodes every 3 to 6 µm. The narrower the grooves and the shorter the distances between them, the better the performance.

[…]

The best-performing grooved electrodes were also significantly more durable than regular electrodes, displaying 170 percent higher current density after 500 cycles of activity. The researchers note that pores in conventional electrodes collapse over time due to corrosion, hampering their performance. By contrast, the grooved electrode structures remained relatively intact.

France had suffered great devastation in World War I and did not want to fight the next war on French soil

June 21st, 2023

How Hitler Could Have Won World War II by Bevin AlexanderGermany’s original plan for the attack in the West was astonishingly modest, Bevin Alexander argues, in How Hitler Could Have Won World War II:

It aimed at no decision. It didn’t even anticipate a victory over France.

The initial proposal, produced on Hitler’s orders by the Oberkommando des Heeres (OKH), or army command, in October 1939, hoped merely to defeat large portions of the Allied armies and gain territory in Holland, Belgium, and northern France “for successful air and sea operations against Britain and as a broad protective zone for the Ruhr” industrial region east of Holland.

[…]

Once the Germans tipped their hand, the Allies intended to throw forward strong forces to meet the Germans in Belgium, though it was the wrong thing to do. The sensible course would be to remain in already prepared defenses along the Belgian frontier, or withdraw to the Somme River fifty miles south, form a powerful defensive line, take advantage of the Allies’ two-to-one superiority in artillery, and launch a counterstroke against the exposed southern flank of the Germans as they drove westward.

[…]

But France had suffered great devastation in World War I and did not want to fight the next war on French soil.

[…]

They expected to use the Dyle, a north-flowing river some fifteen miles east of Brussels, as the main defensive barrier, sending their most mobile forces forty miles farther east to the Meuse (Maas) River to slow the German advance.

[…]

It required their main forces to abandon already built fortifications along the frontier, move rapidly to the Dyle, and dig a new defensive line in the two or three days they were likely to have before the Germans arrived.

[…]

They anticipated a stalemate, the same condition the Germans had to accept at the end of the autumn battles in 1914. The only improvement would be that the coast of northern France, Belgium, and Holland would be available to pursue a naval and air war against Britain.

[…]

With Rundstedt’s approval, Manstein proposed that the main weight of the German attack be shifted to Army Group A and the Ardennes, a heavily forested region of low mountains in eastern Belgium and northern Luxembourg. He advocated that the vast bulk of Germany’s ten panzer divisions be concentrated there to press through to Sedan on the Meuse River, cross it before a substantial French defense could be set up, then turn westward and drive through virtually undefended territory to the English Channel. This would cut off all the Allied armies in Belgium and force them to surrender.

Manstein urged that a major decoy offensive still should be launched into northern Belgium and Holland under Army Group B, commanded by Fedor von Bock. Bock’s armies should make as much noise as possible to convince the Allies that the main effort was coming just where they expected it. This would induce them to commit most of their mobile forces to Belgium. The farther they advanced, the more certain would be their destruction.

[…]

Walther von Brauchitsch, commander of the Germany army, and Franz Halder, chief of the army staff, did not like the idea of their plan being tossed out, and they did not share Manstein and Guderian’s enthusiasm for tanks.

[…]

Manstein and Guderian were certain the Meuse could be breached quickly with only panzer divisions and Luftwaffe bombers, and they believed speed would guarantee that the French would not have time to bring up enough troops to stop them. Speed also would ensure that few enemy units would be in place to block the panzers as they drove right across France to the Channel.

[…]

On February 17, Manstein was summoned to Berlin to report to Hitler for an interview and luncheon, along with other newly appointed corps commanders.

[…]

On February 17, Manstein was summoned to Berlin to report to Hitler for an interview and luncheon, along with other newly appointed corps commanders.

[…]

“I found him surprisingly quick to grasp the points which our army group had been advocating for many months past, and he entirely agreed with what I had to say,” Manstein wrote later.

[…]

Manstein’s idea became known in the German army as the Sichelschnitt, or “sickle-cut plan,” an apt description signifying that a strong armored thrust would cut through the weak portion of the Allied defenses like a harvester’s sickle cut through soft stalks of grass or grain.

[…]

It was a radical and astonishing transformation and the best military decision Adolf Hitler ever made. By shifting the Schwerpunkt to the Ardennes Hitler set up the conditions for an overwhelming victory that could transform the world.

Florida county under quarantine after giant African land snail spotted

June 20th, 2023

Part of Florida’s Broward County is under quarantine after giant African land snail spotted:

Florida’s agriculture officials have contended with the giant African land snail before, and in the past referred to it as “one of the most damaging” mollusk subtypes in the world. The snail is unusually large, growing to be as long as 8 inches as an adult, and can procreate in enormous quantities as it lays thousands of eggs at a time. It poses significant threats to vegetation, consuming at least 500 different types of plants as well as paint and stucco. In addition to causing property damage, the snails also pose serious health risks for humans, as they carry a parasite called rat lungworm that can cause meningitis.

Officials set a quarantine order for Pasco County, about half an hour north of the city of Tampa, last summer, after confirming at least one sighting of the invasive snail species. More than 1,000 giant African land snails were captured there over the course of several weeks, said agriculture commissioner Nikki Fried at the time, and most were found alive.

The giant snails, which, authorities believe, likely arrived in Florida when someone brought it home to the U.S. as a pet, are notoriously difficult to eradicate and getting rid of them entirely can take years. Florida’s agriculture department has recorded only two instances where the snail was fully eradicated, since infestations were first reported in the state in the 1960s.

Do ten times as much

June 20th, 2023

Bryan Caplan”s go-to advice is to do ten times as much:

Almost no one learns how to speak a foreign language very well in school. By the numbers, it’s tempting to declare, “Learning a foreign language is impossible.” But that’s plainly false. Going from zero to fluency is ultra-rare, but I’ve seen it happen.

How does fluency happen? First and foremost, people who attain fluency practice a lot more than the typical foreign language student. “A lot” doesn’t mean 10% more, 25% more, or even 100% more. People who attain fluency practice about ten times as much as the typical person who is officially “learning a foreign language.” Sure, the quality of practice matters, too; immersion is the best method of foreign language acquisition. But unless you’re willing to give ten times the normal level of effort, fluency is basically a daydream.

When I see the contrast between people who succeed and fail, I generally witness a similar gap in effort. During my eight years in college, I spent many thousands of hours reading about economics, politics, and philosophy. Since high school, I’ve spent over ten thousand hours writing. When young people ask me, “How can I be like you?“ my first thought is, again, do ten times as much.

[…]

But my advice is usually far more practical than it sounds, because most people who “want to succeed” barely lift a finger most of the time. Saying ten times as many kind words to your friends is easy in a world whether most people only say two or three such sentences weekly. Cold emailing ten times as many successful people in your field for advice is easy in a world where most people do so once in a lifetime. Never underestimate your fellow man’s lack of initiative.

Take parenting. Most readers summarize my Selfish Reasons to Have More Kids as “Parenting doesn’t matter.” But that is only one possible interpretation of the twin and adoption data. The data is also consistent, however, with the theory that most parents are barely trying to get results — at least on many relevant margins.

[…]

If you want to learn a foreign language, you need to budget about two thousand hours. If you want to master a technical subject, you need to budget about five thousand hours.

[…]

Either that, or admit that you’ve got higher priorities. No one succeeds at everything. If you’re not willing to do ten times as much, just level with yourself: “I’ve got better things to do than learn a foreign language.” “I’ve got better things to do than become a great economist.”

[…]

Pick your battles, friends. And wherever do you choose to fight, do ten times as much.

Ted Kaczynski’s 1979 Autobiography

June 19th, 2023

When I finally read Ted Kaczynski’s manifesto, he didn’t seem like a mad genius. His 1979 Autobiography, on the other hand, raises some red flags:

I am told that I had three bad experiences before I was old enough to remember. I pulled a pot of boiling water off the stove and was scalded very severely. I fell on my chin with my tongue between my teeth, so that my tongue was badly injured and needed a great deal of stitching-up. I had an undiagnosed allergy to eggs, which caused me to swell up enormously all over my body. I was hospitalized for, I think, a week, with the allergy.

Apparently I took the hospitalization very badly. I am told that my parents were not permitted to spend much time visiting me, that I was much tormented (inadvertently) by inquisitive doctors, and that I was made extremely frightened and miserable by all this. My parents say that by the time I came out of the hospital I had become completely inert and would neither smile, nor cry, nor respond to attention in any other way. I conjecture that this experience is responsible for my stubbornness and for my high resistance to physical and especially to psychological pain…

The problem is particularly acute in Los Angeles and San Francisco

June 19th, 2023

A recent Boston Consulting Group survey found that many office buildings are at risk of becoming “zombies,” with low usage, high vacancy and quickly diminishing financial viability:

The problem is particularly acute in Los Angeles and San Francisco, where weekday office building use has fallen to around 40%. As a result, in both cities, public transit revenue has plummeted by 80% or more, and office property values and tax revenues may drop by as much as half, according to our analysis of public data.

Rising interest rates are compounding the financial pressure for building owners, whose rental income stands to drop 35% to 45% as corporate leases expire in both San Francisco and Los Angeles. Higher borrowing costs coupled with lower valuations could leave some owners owing more than their buildings are worth, leading in turn to a wave of defaults that suddenly make lenders the owners and managers of these buildings. In February, a fund managed by Brookfield Properties defaulted on $784 million in loans on two well-known office skyscrapers in downtown L.A., which was seen by some as a turning point for the U.S. office market.

Nearly 21% of New York City’s roughly 1 million schoolchildren receive special education services

June 18th, 2023

New York City’s public school system is struggling to address a decades-long special ed bottleneck:

In 2020-21, nearly 21% of New York City’s roughly 1 million schoolchildren received special education services, compared to a national average of 15%.

When you don’t have kids hanging out on the street, there’s no one to shoot or do the shooting

June 17th, 2023

In 2002, Bill Bratton took over as chief of the LAPD and applied what he had learned as New York City’s police commissioner:

Central to Bratton’s approach in New York was a system called CompStat, short for computer statistics. CompStat involved the real-time statistical monitoring of crime reports, giving cops, and their chain of command, data to which they could be held accountable. Bratton also believed in what has been called the broken windows theory, based on an argument (still much contested) put forward in 1982 by social scientists James Q. Wilson and George L. Kelling, that broken windows or other forms of decay beget further deterioration, and that preventing serious crimes requires a focus on combating blight and petty forms of lawlessness.

When Bratton brought CompStat to the LAPD, it showed commanders where to deploy resources, and it meant the police, and especially division captains, could be evaluated according to reductions in crime in their territory. To fight chronic understaffing at the LAPD, Bratton lobbied for more hiring. Under mayors Richard Riordan and Jim Hahn, the LAPD had grown to 9,000 officers. Bratton and mayor Antonio Villaraigosa took it to 10,000.

The LAPD also began to make use of a tool that had previously been used sparingly: the gang injunction, essentially a ban on gang members hanging out together in public. The gang injunction spent much of the 1990s in court before being narrowly ruled constitutional, but law enforcement valued it. Today, Los Angeles alone has at least 44 injunctions against 72 street gangs. Gang members seen on the street together can be jailed on misdemeanor charges. Other towns and counties followed LAPD’s lead.

All this had a major effect: It drove gang members indoors. Drug dealing continued, and so did other forms of crime, including identity theft. Gang members became more adept at using the Internet to promote their gangs and belittle rivals. But boasting and threatening online doesn’t require the commitment or violence of classic L.A. street gang-banging, nor does it blight a neighborhood. “When you don’t have kids hanging out on the street,” says George Tita, the UC Irvine criminologist, “there’s no one to shoot or do the shooting.”

[…]

Prosecuting street gangs has meant abandoning the previous focus on kingpins. “‘Cut off the head and body dies’ just isn’t true” when it comes to Southern California street gangs, says Brunwin. “You have to go after everyone—anyone who had anything to do with, supported, or touched the organization. You have to have an effect on the structure, its daily operation. The only thing that works is adopting a scorched-Earth policy.”

Members of the early 20th century English upper class tended to have portfolios weighted towards land and government bonds

June 16th, 2023

Byrne Hobart looks at emergency portfolios for worst-case scenarios:

Physical gold, for example, retains some of its value even if the financial system collapses. On the other hand, the old coins we have are often recovered from hoards that someone buried and never dug up, often because of war, famine, plague, or revolution.

[…]

Members of the early 20th century English upper class tended to have portfolios weighted towards land and government bonds, exactly what you’d buy if you were certain of disaster but uncertain about whether it would be inflationary or deflationary. But after the First and Second World Wars, they got the worst of both worlds: inflation high enough to devalue the purchasing power of their bonds, taxes high enough to render the real return from their land negative.

[…]

China’s communist revolution was one of the most thorough economic levelings in human history, one so effective that the children of the elite were actually poorer than average for a while, but then recovered and by the early days of China’s opening-up, and were better-off than ever. Similarly, in the post-Civil War South, the descendants of slave-owning families ended up about as well-off as other rich people, even though their land was seized, their currency depreciated to nothing, and the source of their wealth was banned by the Constitution.