Tag Archives: being and seeming

How superstition grows out of science

Priests in Ancient Egypt could predict eclipses and the floods of the Nile by observing the stars and the Moon and recording their previous positions when the events of interest happened. The rest was calculation, nothing magical. Ordinary people saw the priests looking at the stars and predicting events in the future, and thought that the stars magically told priests things and that the prediction ability extended to all future events (births, deaths, outcomes of battles). The priests encouraged this belief, because it gave them more power. This is one way astrology could have developed – by distorting and exaggerating the science of astronomy. Another way is via navigators telling the latitude of a ship using the stars or the sun. People would have thought that if heavenly bodies could tell a navigator his location on the open sea, then why not other secrets?
Engineers in Ancient Rome calculated the strength of bridges and aqueducts, and estimated the amount of material needed for these works. Ordinary people saw the engineers playing with numbers and predicting the amount of stones needed for a house or a fort. Numbers “magically” told engineers about the future, and ordinary people thought this prediction ability extended to all future events. Thus the belief in numerology could have been born.
When certain plants were discovered to have medicinal properties against certain diseases, then swindlers imitated doctors by claiming that other natural substances were powerful cures against whatever diseases. The charlatans and snake oil salesmen distorted and exaggerated medicine.
Doctors diagnosed diseases by physical examination before laboratory tests were invented. Thus a doctor could look at parts of a person’s body, tell what diseases the person had, and predict the symptoms that the person would experience in the future. Exaggerating this, palm readers claimed to predict a person’s future life course by looking at the skin of their palm.
In the 20th century, some medicines were discovered to be equally effective at somewhat lower doses than previously thought. Then homeopathy exaggerated this by claiming that medicines are effective when diluted so much that on average not a single molecule of the drug remains in the water given to the patient.
In all these cases, superstition only adds bias and noise to scientific results. Science does not know everything, but it is a sufficient statistic (https://en.wikipedia.org/wiki/Sufficient_statistic) for superstitious beliefs, in the sense that any true information contained in superstition is also contained in science. Nothing additional can be learned from superstition once the scientific results are known.

On the optimal burden of proof

All claims should be considered false until proven otherwise, because lies can be invented much faster than refuted. In other words, the maker of a claim has the burden of providing high-quality scientific proof, for example by referencing previous research on the subject. Strangely enough, some people seem to believe marketing, political spin and conspiracy theories even after such claims have been proven false. It remains to wish that everyone received the consequences of their choices (so that karma works).
Considering all claims false until proven otherwise runs into a logical problem: a claim and its opposite claim cannot be simultaneously false. The priority for falsity should be given to actively made claims, e.g. someone saying that a product or a policy works, or that there is a conspiracy behind an accident. Especially suspect are claims that benefit their maker if people believe them. A higher probability of falsity should also be attached to positive claims, e.g. that something has an effect in whatever direction (as opposed to no effect) or that an event is due to non-obvious causes, not chance. The lack of an effect should be the null hypothesis. Similarly, ignorance and carelessness, not malice, should be the default explanation for bad events.
Sometimes two opposing claims are actively made and belief in them benefits their makers, e.g. in politics or when competing products are marketed. This is the hardest case to find the truth in, but a partial and probabilistic solution is possible. Until rigorous proof is found, one should keep an open mind. Keeping an open mind creates a vulnerability to manipulation: after some claim is proven false, its proponents often try to defend it by asking its opponents to keep an open mind, i.e. ignore evidence. In such cases, the mind should be closed to the claim until its proponents provide enough counter-evidence for a neutral view to be reasonable again.
To find which opposing claim is true, the first test is logic. If a claim is logically inconsistent with itself, then it is false by syntactic reasoning alone. A broader test is whether the claim is consistent with other claims of the same person. For example, Vladimir Putin said that there were no Russian soldiers in Crimea, but a month later gave medals to some Russian soldiers, citing their successful operation in Crimea. At least one of the claims must be false, because either there were Russian soldiers in Crimea or not. The way people try to weasel out of such self-contradictions is to say that the two claims referred to different time periods, definitions or circumstances. In other words, change the interpretation of words. A difficulty for the truth-seeker is that sometimes such a change in interpretation is a legitimate clarification. Tongues do slip. Nonetheless, a contradiction is probabilistic evidence for lying.
The second test for falsity is objective evidence. If there is a streetfight and the two sides accuse each other of starting it, then sometimes a security camera video can refute one of the contradicting claims. What evidence is objective is, sadly, subject to interpretation. Videos can be photoshopped, though it is difficult and time-consuming. The objectivity of the evidence is strongly positively correlated with the scientific rigour of its collection process. „Hard” evidence is a signal of the truth, but a probabilistic signal. In this world, most signals are probabilistic.
The third test of falsity is the testimony of neutral observers, preferably several of them, because people misperceive and misremember even under the best intentions. The neutrality of observers is again up for debate and interpretation. In some cases, an observer is a statistics-gathering organisation. Just like objective evidence, testimony and statistics are probabilistic signals.
The fourth test of falsity is the testimony of interested parties, to which the above caveats apply even more strongly.
Integrating conflicting evidence should use Bayes’ rule, because it keeps probabilities consistent. Consistency helps glean information about one aspect of the question from data on other aspects. Background knowledge should be combined with the evidence, for example by ruling out physical impossibilities. If a camera shows a car disappearing behind a corner and immediately reappearing, moving in the opposite direction, then physics says that the original car couldn’t have changed direction so fast. The appearing car must be a different one. Knowledge of human interactions and psychology is part of the background information, e.g. if smaller, weaker and outnumbered people rarely attack the stronger and more numerous, then this provides probabilistic info about who started a fight. Legal theory incorporates background knowledge of human nature to get information about the crime – human nature suggests motives. Asking: „Who benefits?” has a long history in law.

“Relative to opportunity” evaluation and anti-discrimination laws

Most countries have some anti-discrimination laws, requiring employers to pay people with different productivities equally, or to give someone who took parental leave their job back after they return. One reason why unequally productive people are paid equally is evaluation “relative to opportunity”, i.e. the bar for a promotion or a raise is lower for someone from a historically disadvantaged group or who has family responsibilities. Suppose that there is a consensus in society for supporting certain groups. Why might the cost of this support be placed only on specific employers, namely those who employ the target group? Why doesn’t the support take the form of direct subsidies from the government to the target group, financed by taxing all employers equally?
An explanation from political economy is as follows. Clever people in society or government want to pay a larger subsidy to high-income members of the target group, perhaps because the clever people are themselves high-income and belong to the target group. However, the majority of voters would not like high-income people getting a bigger subsidy. So the clever people disguise the subsidy as something that looks equal, namely every member of the target group gets the same duration of parental leave, the same guarantee of their job back at the end of leave, the same privileges and special treatment for promotions and raises. The value of these guarantees and privileges is greater for higher-paying jobs. For example, a promotion from a high-paying job usually gives a bigger salary increase than from a low-paying job. A guarantee of getting a high-paying job back after parental leave is worth more than a guaranteed low-paid job. Thus the support provided to the high-income members of the target group is more valuable.
Further, productivity at a high-income job is typically more responsive to the employee’s human capital, and the skills deteriorate faster. A truck driver who has not driven for some years retains a greater fraction of driving ability than a surgeon retains from surgical technique after not operating for the same number of years. The productivity difference between an employee returning from parental leave and someone continuously employed is on average greater for higher-paying jobs. So the cost to an employer of keeping a job for a returning employee instead of hiring a new person is greater if the job is higher-paid. The subsidy to the high-income members of the target group thus costs more per person.
Income is positively correlated with intelligence, so the smart members of the target group are likely the wealthy members who benefit from this kind of unequal subsidy. They are likely to vote and campaign in favour of the unequal support, instead of an equal cash subsidy for everyone. The less smart members of the target group who lose from an unequal subsidy (compared to an equal one) are less likely to understand that they lose. This makes them abstain from opposing the unequal subsidy.
In effect, the smart members of the target group redistribute a baseline-equal subsidy from the less smart (and less wealthy) to themselves, at the social cost of losing some efficiency in the economy. Keeping a job for someone when a more productive potential hire is available means losing the difference in the productivities of the two people. Such efficiency losses are typical of re-distributive policies that are not cash transfers.
In principle, the cost of the current policies could still be equally distributed between employers by taxing them all and subsidising those who employ the target group. Or equivalently, taxing only those who don’t employ the target group. However, to equalise the cost to employers, the firms employing highly-paid members of the target group must be compensated more than the ones employing low-paid members. The differential compensation to firms would call attention to the unequal support that people with different incomes are receiving, thus weakening the disguise of the subsidy. The clever people want to avoid that, so do not campaign for equalising the costs of anti-discrimination laws across employers.


Bullshido is a term used for martial arts that make false claims about themselves, for example that the art helps a much smaller person defeat a larger one, or defend against a knife barehanded, or defeat multiple opponents. Such claims are marketing, but believing them puts people in danger, because instead of screaming and running, the believers may try to fight against hopeless odds and get injured. There are websites dedicated to exposing and ridiculing bullshido.
In addition, one should distinguish fighting and self-defense, and thus also unarmed combat training from self-defense classes. Detailed explanations are e.g. on the website NoNonsenseSelfDefense.com. Briefly, self-defense is about (1) avoiding crime (specific times, places, people), (2) noticing dangerous situations developing, (3) escaping them, (4) negotiating if escape is impossible (giving away your wallet and phone to avoid a beating), and (5) only as a last resort, fighting. Just like a castle has multiple concentric walls, self-defense has multiple concentric layers. Just like war happens when diplomacy and sanctions have failed, fighting happens when all other layers of self-defense have failed.
Returning to bullshido, one should apply the general principle that the burden of proof is on the maker of a claim. Some claims are hard to test without substantial danger, for example defending against a knife barehanded. But fighting larger people or many of them can be done with reasonable safety using boxing gloves, shin pads, soft helmets and similar protective equipment. The test should be scientifically rigorous, not like the demonstrations of martial arts clubs where the attackers and defenders have agreed on the moves beforehand. Such demonstrations are just theatre. In a real test, the attackers and defenders should not know each other, should not have the opportunity to collude, and each should be motivated to succeed, e.g. by a significant monetary prize for the winner. All moves should be made with maximal speed, without unrealistic „winding-up” movements calling attention to when and where the punch or kick will come.
Tests of this sort have been conducted for bare-handed fighting, namely in the Ultimate Fighting Championship (UFC) in the 1990s. There were several matches between traditional martial artists (karate, sumo) and more modern martial artists (Brazilian jiu jitsu, kickboxing). Traditional martial arts did not fare well. The evolutionary process in UFC and similar competitions, e.g. Pride, has led to the development of mixed martial arts (MMA) that is actually effective in bare-handed one-on-one fighting.
In general, martial arts that permit a wide range of full-speed, full-strength moves in competitions encourage more realistic training and improve fighting ability. Some traditional martial arts are included in this category, e.g. judo, wrestling.
Knife-defense can be tested with some realism using imitation knives. Even a rubber knife or marker pen can penetrate an eye or throat, so when using these, safety goggles and neck protection should be worn. A better fake knife is made of foam rubber and lightly coated in paint. The paint makes it very obvious when the knife has connected with the body. Without such an objective marking of a „cut”, the bullshido artist subject to the test can claim that the fake knife did not connect with them. A shortcoming of such a test is that the knife usually connects with a hand or forearm first, in which case many types of cuts from a real knife would make the arm useless and let the attacker get to the torso. Examples are cutting a nerve, tendon or muscle needed to move the arm. A safe fake knife does not make a hand useless, so the defender can continue using it in defense. There should be a referee competent to evaluate the damage to the hand or other part of the body that would have resulted from the „cut” (paint stripe) that the fake knife made. The referee should order the defender not to use a limb if that limb would be useless had the cut been real. One way to make a fake knife more realistic, but slightly more dangerous, is to add an electroshock ability to the fake knife. This can make a contacted limb go numb and become less useful for defense.
The idea of the knife measuring contact in some way has been used in fencing. The foils used sometimes have a pressure sensor in the tip that detects a touch on the opponent.
Training with an imitation knife and a motivated opponent who does not collaborate in his or her defeat will quickly cure the illusion of being able to defend against a knife barehanded. The same applies to most weapons, e.g. sticks, chains.
I have two stories about my experience with bullshido. In my early teens I took karate classes for a couple of years. Among other things, the classes taught how to twist an opponent’s arm or hand in various ways (and catching their punching hand prior to doing so). In training, I managed quite well to catch a punch and put the opponent on the ground with an arm twist. This is because the training was theatre and the opponent collaborated.
Upon hearing that I had learned martial arts, an adult construction worker offered to let me practise on him in the following way. He held his hand steady in front of him and I could try to twist it in any way I liked, using two hands against his one. He did not interfere with me in any way, just held the hand steady against any force. He was a physically average man, not some weightlifter or giant. I was about 15 years old, above average in size (about his height) and in good physical shape, but I could not twist his arm in any way I tried, using all my strength. The claim that non-full-contact martial arts can teach a weaker person to defeat a much stronger one is false. Even realistic training in modern martial arts is limited in how much it can improve a person’s chances of winning a fight.
Do unrealistic martial arts still help a little, e.g. enable a practitioner to win against a slightly stronger, or equal person? This is where the next story comes in.
After a year or two training karate twice or more per week, over 1.5 hours per session, I participated in a competition internal to the karate school (only members of that school took part). I was matched against a slightly smaller and weaker opponent who had only taken karate classes intermittently for a few months. In karate class, we had practised punches that ended an inch short of the opponent, to avoid hurting our training partners. I was a good student, as it turned out, because during the competition, all my punches ended an inch short of my opponent. I tried to overcome this in-trained behaviour, but could not. My opponent, on the other hand, had not been trained much and used the most common street-fighting overhand punches (called haymakers). These mostly landed on me and were moderately effective when they did. I lost badly.
The lesson from this is that bullshido actually reduces a person’s fighting effectiveness, unlike for example ballet or yoga, which train some aspects useful for fighting (strength, stamina, balance) and don’t ingrain ineffective moves. Unrealistic martial arts „help” a person lose against a smaller, weaker opponent, while falsely convincing the person of his or her fighting ability.

Camouflaged encryption

Many governments (US, Australia, all dictatorships) want to make end-to-end encryption illegal and prevent IT firms from providing it. The open-source community can create their own encryption software, but the creators and users of this could be punished as well. The reasoning of the governments for banning encryption is that criminals and terrorists use it. However, the same reasoning applies to knives, guns and cars, which are used much more directly to harm people and yet are strangely excluded from the ban. This contradiction makes me doubt the motives of these governments.
The obvious solution to a ban on some software is to camouflage it and its products. The code for the encryption software could be hidden in a seemingly nonexistent part of computer memory or blended in one log file among many, perhaps encrypted as well.
The encrypted messages passing through the internet should not look like encrypted messages, but would be embedded in innocuous-looking files. A simple way is to change the colour of some pixels in a self-made photo or video file, with the locations of the relevant pixels being known to the sender and receiver, but secret from others. The colours of the pixels can encode the data. Someone intercepting the picture or video would have to spend significant resources analysing it to find whether some pixels are of an unusual colour, especially if the starting image is riotously colourful and confusing. Publicly available images are not useful, because comparing the message-image with the original reveals the changed pixels.
A more sophisticated version of this idea has already been done by http://camouflage.unfiction.com/ A similar idea is to hide one’s browsing history in random websurfing (http://www.qqqtech.com/about.html), but this only hides the relative frequencies of websites visited, not the fact of visiting a site on a government watchlist that most people don’t visit.

Conferences and seminars as cargo cults

I wrote about the wastefulness of physically travelling to conferences or to give seminars, because one could give a presentation via a video call over the internet (http://sanderheinsalu.com/ajaveeb/?p=442). Other than habit or tradition, why would scientists organise conferences and seminars with physical attendance? One explanation I offered was that physical presence is a commitment device. Herding is another justification to any tradition. Irrationality is a third, which complements herding.

Holding conferences and seminars may be rational if top researchers are presenting and providing feedback, because there is much to learn from them. Such workshops may not be useful if the participants are not on the research frontier. Nonetheless, the low-achievers may organise such gatherings, because they want to publish like the high-achievers, and they perceive that the high-achievers benefit from the research meetings of large groups. A cargo cult means imitating someone’s behaviour to reach the same goals as them, but without understanding the reason why their actions lead to the results they do. The lack of comprehension of the underlying mechanism leads the imitation subtly astray, so it does not obtain the desired results. The conferences and seminars of low-achievers are a cargo cult if the following hold: only the participation of high-achievers makes research meetups useful, the high-achievers do not attend low-prestige meetups, and the low-achievers do not understand the above. It is difficult to test the usefulness of any action in research, because publication success is noisy, influenced by many factors and with long delays. Thus it is difficult to test whether there is a cargo cult in the less advanced levels of the research community.

Besides improving quality, the feedback of top researchers can increase publication chances by making the research of those lower in the scientific hierarchy conform to the tastes of the top. This is a horizontal differentiation effect – matching idiosyncratic tastes. It is not vertical differentiation (improving quality). If top people as referees and editors favour a certain field of research or ideology, then presenting work to them may uncover their biases and enable an author to pander to them.

Another way that presenting helps with publication is the familiarity effect. When the referee or editor has seen the paper presented before reading it, then the content is familiar and thus easier to understand. The reader may interpret the ease of comprehension as clarity of the paper, not familiarity of the material. Clear writing and well-structured ideas are a positive signal to the referee and increase the publication chances.

If the second-best people imitate the highest-achievers, then the third-best may imitate the second-best, etc. The cargo cults may be multilayered. Such imitation of imitators is called herding. It may sometimes be individually rational, but may lead to socially suboptimal ignoring of later information in favour of imitating the decisions of those who acted based on earlier info. Herding strengthens the effects of mistaken imitation, thus worsening cargo cult effects.

Cargo cults occur widely – any time there is a fad, fashion or bubble, some people jump on the bandwagon because their role models did, without asking why the role models did so. The personal situation of the trailbreakers may make it rational for them to act in a certain way, but the different circumstances of the followers may make imitation counterproductive for them. An example is creating a financial bubble to profit from it (pump-and-dump strategy). The starters profit from the amount invested by the followers. The last people to become followers lose their investment when the bubble bursts. I am not the first to compare the research community to a pyramid scheme – search „Profzi scheme” online.

Remembering the sacrifice

Many times and in many places I have seen a call to remember the sacrifice of the soldiers who died in some past conflict. Often, this call seems an attempt to direct attention away from the misguidedness of the particular conflict or the incompetence and selfish motives of the leadership who decided to enter the war. It tries to make people focus on the noble courage of the soldiers, not the sordid power-hunger of the rulers. The bravery of soldiers is discussed in another post (http://sanderheinsalu.com/ajaveeb/?p=595); here I would like to clarify this sacrifice business.

If the soldiers volunteered under reasonably accurate information about the reasons for the conflict and the chances of success, then indeed they chose to sacrifice themselves for the cause. Then we should remember their sacrifice. If, however, they were conscripted (dictatorships often call this volunteering) using the threat of punishment for them or their family, then they did not make the sacrifice any more than a sacrificial animal sacrifices itself. Others sacrificed the conscripts to further their own ends.

These ends are unlikely to prioritize defeating an evil regime and making the world a better place, although the propaganda claims this was the objective. Mostly the goal of leaders is to preserve and expand their power, whether by defending the country against takeover or conquering additional subjects and wealth. Even if this is acknowledged, current propaganda may point out some good side effect of sacrificing the soldiers, e.g. defeating an old enemy. This is again a distraction attempt. The world is complex and interconnected, so every event, including a mass death, has some beneficial side effects, just like every event has some negative side effects. One should consider the overall consequences of an event, not just one side effect.

If the soldiers genuinely volunteered, but due to being misled by propaganda, then they wanted to sacrifice themselves for one cause, but their leaders sacrificed them for another. Usually volunteers underestimate the length of the war and the probability of dying. Thus even when they know the true goal of the conflict, the sacrifice they are led to is larger than the one they intended to make.

The most clear and direct self-sacrifice is made by suicide bombers. They probably think that their bombing serves a good purpose, but such belief is almost always misguided. Religious indoctrination of the bombers manipulates them into believing in a noble cause, hiding the true goals of the leaders ordering the bombing.

I have not heard many calls to remember the sacrifice of present-day child soldiers. Rather there are calls to pity and save them. The situation of many soldiers in many wars has been similar to children forced to fight – ignorance and fear of punishment. Obeying the conscription order often offers a greater survival probability than refusal.

Instead of remembering the sacrifice of conscripts, we should remember them being sacrificed. Remember with pity. Remember to prevent.

On military bravery

All countries and armed groups emphasize the bravery of their soldiers for propaganda purposes. Such claims are made regardless of whether there is any actual valour. Going to a dangerous situation or even certain death is not necessarily courageous, in particular if there is no knowledge of the danger or no choice. Are sheep going into a slaughterhouse brave? They are calmly walking to certain death, after all. But usually this is not ascribed to courage, but to ignorance. Analogously, soldiers used in early tests of the physiological effects of radiation exposure who were marched through an area of a recent nuclear explosion are not considered brave. They did not know the cancer risk.

If there is no choice, which usually means there are only perilous choices, then putting oneself in danger is not usually accounted brave. Jumping out of a burning building offers a higher probability of survival, so people do it despite the substantial risk of falling to death. When a sufferer of a painful terminal disease chooses euthanasia, this early death is commonly not considered brave. Some cultures even believe suicide to be a sign of cowardice. If a military has a well organized system for catching deserters and administering the death penalty to them (and their family in some regimes), then a soldier charging enemy machineguns is merely maximizing his survival probability. The enemy might miss, the firing squad rarely does.

The greater the probability of victory for one’s own side, the less attractive desertion becomes, because being caught is more likely. This explains the propaganda emphasis on own victories and the punishment of “defeatist talk” in wartime. The greater the military advantage of a party in an armed conflict, the less bravery its soldiers need.

Genuine bravery exists, but it is rare. Evolution favours cowardly bullies who attack the weaker (prey) and run from the stronger (predators). People who face no compulsion to fight in a war and know the dangers, yet still join, are brave. Freedom fighters (insurgents from the other side’s viewpoint) against a dictator qualify. With the caveat that only joining the fight initially requires bravery – after that, losing would mean being tortured to death by the dictator, so continuing the war is the safer option. Similarly, volunteering for the military requires some bravery (the more the greater the likelihood of being sent into danger), but once military law applies, desertion is usually more dangerous than the duty.

Military courage is proved for those who start the war as a weaker side against a stronger, if a continuing peace is not a slow death. Peasant revolts were often driven by hunger, meaning the participants may have perceived the probability of death from starvation as higher than the probability of being killed by the aristocrats.

People who have never faced an informed choice between a safe and a dangerous option may be “latently brave”, in the sense that given such a choice, they may exhibit courage. They are not proved brave, however, until they have made the choice. There are likely to be some latently brave people in the world’s militaries and armed groups. Probably a greater percentage than among the general population.

There are some proven brave folks even in the militaries of powerful countries, but the proof requires knowingly choosing a dangerous option when there is no future punishment for cowardice. For example, when nobody would know of the choice.

A topical question is whether suicide terrorists and other fighting religious fanatics are brave. Their behaviour may be driven by the fear of punishment either in the afterlife or by their fellow fanatics. It may also be due to ignorance – believing in an afterlife is like believing that one cannot really die and thus the danger is not real. In both cases, no courage is required for choosing death.

The belief in the impossibility of dying may even be literal – W.E.B. Griffin had a story of a witch doctor convincing the fighters of his tribe that his magic had made them immune to bullets. Great was the fighters’ surprise later… Their charge with spears against guns was not due to bravery, however.

On backpackers and low-spending tourists

Countries encourage tourism to make money. The same goes for local governments, tourism industry associations and tour firms. Some places provide options for low-spending tourists like backpackers, despite not making much money from them. These options may be cheap campsites, backpacker hostels, allowing hitchhiking and work-travel visas. At first sight, any positive revenue from poorer tourists would justify welcoming them. This simple revenue calculation, however, neglects the substitution effect and dynamic demand.

Substitution means that if cheaper travel options are available, then some tourists who would have spent more in the absence of these options now spend less. For example, a person who would stay in a hotel if there was no other accommodation, stays in a backpacker hostel instead. On the other hand, if all options are expensive, then the poorest tourists do not come at all. There is a tradeoff between the number of tourists and the average tourist’s spending. If introducing cheaper options leads to many tourists switching to these, but does not attract many additional low-spending people, then creating these cheaper options reduces total profit.

Dynamic demand means that a person who has toured a particular location once changes his or her likelihood of going there in the future. For example, having seen a tourist site, a person does not visit it again. Or someone going on vacation and liking the location starts going there year after year. If a region encourages young, low-income people to visit as backpackers, then it may increase or decrease future visits by these people when they are older and wealthier. In particular, if people do not tour the same location again (and spend more when older), then encouraging them to visit when young reduces the total profit from them over their lifetime.

The fact that some regions welcome backpackers has several possible explanations. There may not be much substitution, or a visit may increase future visits. The tourism industry may not have thought this through and may be reducing their own profit inadvertently. Or the government may have other objectives than taxes from the tourism industry. For example, allowing people from other countries to visit cheaply may make these people friendly to the host country, which may yield some nonmonetary benefit in international relations.


Deflation of academic publications

The top journals publish a similar number of articles as decades ago, but there is a much larger number of researchers competing to get their work into a top journal. Correspondingly, it is more difficult over time to get a paper into a given journal. If articles are analogous to currency in the academic world, then this would be deflation: the value of the currency rises over time. If articles are like goods and services, but research effort is the currency that buys them, then there is inflation, because the amount of currency required to buy a given good rises.

The correct comparison between publications in different decades would take into account the increasing difficulty of publishing in a given journal. Instead of comparing papers in the top n journals, a better metric is papers in the top x percent of journals (accounting for the possibly expanding size of each journal). Similarly, being the number one researcher among a thousand in 1901 is less impressive than being the best among a million in 2001. Again the right comparison is by percentile rank, not by “top n” status.

The norms and metrics in academia are largely made by senior, established researchers. If people do not completely account for the deflation, then the top academics benefit from the increasing difficulty of publishing in the top n journals combined with the metric that counts the top n, not the top x percent. The research of old academics that was published in the top n long ago looks the more impressive the more difficult it is nowadays to get a paper into the top n. Comparison by percentile rank would correct for this artificial advantage, so the established members of the profession would not seem as high-achieving relative to new entrants.

A similar change in difficulty has occurred in getting accepted as a student in the top n universities, or getting hired as faculty in these. The right comparison to the students or faculty decades ago would compare the top x percent of universities, with the appropriate correction if the universities have expanded their enrollment or number of jobs.