Spam deterrence by boycotting

The obvious reason for spam of any kind (emails, texts, phone calls, unsolicited mail) is that it is profitable. Thus spam must raise the probability that its target buys or otherwise complies with the spammer’s wishes, e.g. leaves a review. To deter spam, the incentive for it must be reversed – the targeted people should not give in to spammers, but do the opposite (not buy, not leave a review when receiving a „reminder”). I try to follow this strategy. If I remember that a business spammed me, then I try to boycott it, unless it is by far the best option (usually not, spammers are typically shady businesses and bottom-feeders).

Incentives are created by the difference in payoffs, not their level. Thus to deter spam, the buying probability should be lower for a spamming business than for a non-spamming competitor. To create this payoff difference for non-monetary actions, e.g. reviewinig, I leave a review with positive probability when not asked to do so, but certainly avoid reviewing when spammed with reminders.

If the whole society followed the strategy of boycotting spammers, then one possible concern is that spammers would start to use reverse psychology. They would spam in the name of their competitors to make them look like spammers. If customers start boycotting the competitors as a result, then demand shifts to the spammer, which is profitable.

The reverse psychology is unlikely to become a serious problem, because there are typically many competitors and the spammer would have to make most of them look bad to increase its demand significantly. Also, the law usually punishes the use of a fake name more harshly than unsolicited contacting. The competitors whose reputation is tarnished by spam under their name have a stronger incentive to sue its source than consumers just annoyed by the spam.

Formal clothing is a bad equilibrium of a coordination game

What clothing happens to be considered formal is an equilibrium of a coordination game: if most others think that a given clothing item is formal, then a person who wants to be seen as formally dressed is better off choosing that garment. If enough people who aim to dress formally choose certain clothing items, then those garments will be interpreted as formal. Different cultures and eras have considered different clothes formal, e.g. tights for men were formal in Europe during Napoleonic times, but are not now.

Current formal clothing is a bad equilibrium because suits and shirts are difficult to clean, labour-intensive to iron or press, and restrict movement. A better equilibrium would be to interpret as formal some garments that are comfortable, environmentally friendly, easy to care for and cheap. It is unfortunately difficult to change equilibria in a society-wide coordination game, because a majority of people would have to change their beliefs in a short time.

The reason why suits are seen as formal is historical: these were fashionable at the height of the British Empire, which was the richest and the most powerful country in the 19th century, thus a trendsetter in the first era of globalisation. British fashion was copied in North America and Europe, spreading to the colonies from there. Labour-intensive clothes were a way for Victorian nobility to signal wealth, because only the rich could afford to hire enough servants to make and care for their clothes. In many cultures, wearing impractical clothes (toga, long dress restricting leg movemen) has been a way to signal that one does not have to work. Similar signals of leisure were pale skin (because most work was outdoors), soft clean hands (because most work was manual and dirty), straight posture (because work often involved stooping). More extreme signals of leisure were physical changes that made most jobs of that era and region difficult or impossible: women’s foot-binding in East Asia, mandarins’ long fingernails in China.

Contrary to pale skin demonstrating leisure in Victorian Britain, in modern developed countries, a suntan is a signal of wealth, because most work is indoors and most trips to tropical places or simply outdoors are costly and time-consuming vacations. A similar reversal of the meaning of a signal is that a fat belly showed wealth when food was scarce, but in modern developed countries with an obesity epidemic, developing an athletic physique takes time and effort, so being fat is statistical evidence of poverty.

Signals of wealth have always invited cheaper imitations. For example, solariums provide suntanning cheaper than travel to the tropics. Slimness can be faked with liposuction, a corset or less drastically with a tailored waist and vertical stripes that are closer together or narrower at the waist area. The appearance of broad shoulders is achievable by wearing a suit jacket with padded shoulders.

One reason for why a business suit looks the way it does is to make the man wearing it appear taller, slimmer in the waist, and broader-shouldered, thus more masculine and attractive. The V-shape formed by the lapels uses the well-known visual perception error that an object at the open end of a V looks larger than an identical object at the tip of the V. The front of a suit jacket thus creates the appearance of a slim-bellied, muscular man. If the wearer’s belly allows, then a suit jacket usually also has a tailored waist, which further visually narrows the middle of the body. The vertical lines created by the tie and the creases of the pants make the wearer look taller and slimmer, which is often accentuated by vertical stripes on the suit. It is very rare to see a suit with horizontal stripes.

The visual illusion of attractiveness that a suit creates provides a extra incentive to stay in the equilibrium in which suits are considered formal clothing. To ease the transition to a new equilibrium in which the clothes perceived as formal are more practical, the new formal clothes should improve the wearer’s looks even more than a suit. This is not difficult, because many garments may have V-shaped patterns printed on the upper body, vertical stripes on the lower, have a tailored waist and shoulder pads. The patterns and cut may be designed based on psychology research to maximise the athletic appearance of the wearer. Anything achieved with a suit may be replicated and further optical enhancements added, for example printed outlines of muscles and puffed upper sleeves.

Pre-selected health insurance plans for visitors

A half-year visit to a US university under a J1 visa requires US health insurance. In the University of Pennsylvania, the website of the International Students’ and Scholars’ Office says that they have pre-selected some health insurance plans. According to their cover description and comparison websites, these plans offer significantly less cover than similarly-priced plans not pre-selected by U Penn. My spreadsheet comparing the health insurance options is public. Possibly I have missed some aspects of insurance that justify the price difference. Another explanation is that the pre-selection was done by people who do not themselves use these insurance plans (because they are not visitors to the US) and have little incentive to make an effort to choose the best plan. A more negative and less likely interpretation is that the insurance company is providing incentives (such as kickbacks) for the selectors at U Penn to direct visitors to expensive low-cover plans that are profitable for the insurer.

Real estate website improvements

Almost all real estate websites I have read are missing the essential information about a lease from their search filters. The core info is whether the property is available from a certain date to a certain date, whether the minimum and maximum lease lengths allow a tenancy for the specified term, what is the monthly rent for that term. Some websites specify that information in the description of the property, but do not allow searches based on it. On some websites, the rent doubles when the term is halved, which would be good to know from the start instead of after clicking on a search result.

If the property is only rented to a specific class people, e.g. requires a number of years of good rental history, a certain income level, etc, then it would be good to know this at the start of the search, instead of during the application process.

Almost useless info like hardwood floors, granite countertops, historic building, etc should be removed or relegated to the bottom of the page.

In general, any search website should allow the user to remove specific results (that the user has deemed irrelevant) from future searches, like Craigslist does. Being able to save the search like in Craigslist is also a useful feature.

Arranging a virgin birth in a low-tech way

Warning: this Christianity- and Christmas-themed post may offend or disgust. The procedure described is unpleasant for the receiver.

Fertilisation of an egg cell requires sperm to reach it, which does not require breaking the hymen. A thin tube, such as a hollow straw or reed, can be inserted through the small opening in the hymen to pump sperm (obtained via male masturbation) into the vagina. The simplest way to pump the sperm is to suck it into the straw with one’s mouth and then blow it out. Another way is with an enema pump (bulb syringe) that can be constructed with primitive technology: a hollow leather ball glued to a reed using resin, tar or bone glue. The seams of the leather ball can be waterproofed with tar. The ball can be made to spring back into shape after squeezing, e.g. by constructing it with wire hoops or springs inside.

Successful fertilisation with the above method likely requires many attempts, because the probability of pregnancy from unprotected sex during the most fertile part of the menstrual cycle is 30%. Sexual activity causes hormonal changes in the female organism that facilitate fertilisation, which a simple reed insertion probably does not, but it may be possible to create similar hormonal changes with an erotic massage.

The above method can be used to arrange a virgin birth in a primitive society. No miracles are required, although a virgin giving birth may be marketed as miraculous.

Modern in vitro fertilisation technology of course expands the range of ways to engineer a virgin birth.

Protecting a wound or burn that needs frequent access

If it is necessary to put cream on a burn frequently, then a band-aid is inconvenient, because it must be pulled off every time. Also, a band-aid may stick to an oozing wound and reopen it every time it is pulled off. If the damaged skin needs covering, for example because the weather requires thick clothes, then one solution is to stick or tie a small cup-shaped object on top of the wound. Tying is preferable, because removing a stuck object again irritates the damaged area. The edges of the cup should be soft, because these press on the skin (so a plastic bottle cap is a bad idea). One soft-edged approximately cup-shaped object is the eyepiece of swimming goggles.

Swimming goggles protecting wound

The eyepiece is nicely attached to adjustable straps for tying it on with neither too much nor too little pressure. The eyepiece may be flipped over to the side to get access to the damaged skin.

Of course, the location of the wound may cause difficulties in tying swimming goggles on top of it, e.g. on the torso. Even on the arm or the leg, the lengthwise movement of the sleeve or pant leg may push the goggles off, because the strap running around the limb does not resist lengthwise movement well. Then adding some bandages may be necessary.
Overnight, the area under the goggles gets sweaty. To avoid this, small air holes may be drilled in the eyepieces, which of course makes the goggles useless for swimming.

Improvements for hotels

Commonly in hotels the room keycard has to be inserted into a slot for the lights in the room to turn on. An annoyance occurs when the lights are reset each time the card is removed and re-inserted, such as when leaving and re-entering the room (this problem and most of the subsequently mentioned ones are based on Courtyard by Marriott Chennai, but some are based on other hotels). Typically all the lights turn on and the unnecessary ones have to be turned off one by one. A simple and cheap microcomputer could remember the on-off settings of the lights and keep these until reset. Another similar problem is that the temperature of the AC or heating, as well as the fan speed, gets reset when the keycard is removed from the slot. Thus the AC has to be readjusted after each re-entry.

The keycard should work consistently, not require several attempts to operate the lift or open the room door.

It is a nice touch for a hotel to have a steam room, sauna or jacuzzi next to the fitness centre, but it would be even better if these were in working order and clean. Another nice touch is to provide slippers in the room, but if these are child-sized, then they are not very useful for an adult male. If there are two pairs of slippers in a room, then different-sized pairs would be reasonable and almost as cheap to provide as same-sized ones.

If (free) wifi is advertised, then it would be nice if it was working. Wifi problems can be detected automatically (by wifi-enabled devices placed in the corners of the hotel remotest from the routers) without waiting for annoyed guests to contact the front desk.

An electric kettle in the room is good for making tea, but placing glasses next to the kettle invites an absent-minded person to pour hot water into these, which cracks them.

The carpet should not shed hair that sticks to socks and anything else it comes into contact with (by floating in the air for example).

The fitness centres in hotels are typically less than 25 square metres. It is possible to choose machines and weights for a small room in such a way that cardio and all major muscle groups can be trained, but hotels seem to choose the machines randomly, e.g. three ellipticals and a stair stepper, but no rowing machine. Or two quadriceps training machines (leg extension and leg press), but no hamstring training machine (prone leg curl). This is despite the fact that quads are easy to train without a machine (do squats with or without weights), but hamstrings difficult.

A common problem in hotels is street noise in the room, which may be expensive to fix if the hotel construction quality is bad. One hotel in which the room was quiet despite a busy street outside was Sheraton New Delhi. A possible reason for its quietness was that the windows had two layers of packet glass, consisting of two or three layers each.

Hotel breakfasts should have a list of ingredients next to each dish, not just the name of the dish, especially when the name is unfamiliar to most visitors, e.g. the name is in the local language for a traditional ethnic dish. The list of ingredients would be especially helpful to people with food allergies, but the non-allergic would also benefit – it is easier to choose with more info. The ingredients in the list should be ordered, starting with the ones that constitute the largest percentage of the dish.

The arrangement of dishes at buffet meals should make it logistically convenient to get food, i.e. movement to and from the dishes should be unrestricted (no closely placed tables blocking the way) and similar foods should be located together. Sometimes hotels make strange food placement choices, for example I have seen soups and meat dishes alternate. Rydges on Swanston in Melbourne placed all the dishes in a small recess off the dining area, so there was a traffic jam of people trying to get into and out of that nook with their plates.

Made-to-order (live cooking) dishes at buffet meals could be prepared and distributed faster if their order system was computerised and the eaters could order the dishes from their smartphones. Peak demand time can be predicted and the cooking started in advance to speed up the delivery of the dishes. Such just-in-time production has economies of scale, so is especially easy for larger buffets.

The hotel room logistics are often strange, e.g. a narrow corridor leading from the door to the room, with wardrobes built into the side of the corridor. The doors of said wardrobes open outward, blocking the corridor. On the other hand, in the Chennai Marriott bathroom the shower stall and the the toilet were behind the same sliding door. To access the toilet, the door had to slide in front of the shower, and to access the shower, the door closed off the toilet. This would be annoying if two or more people stayed in that suite and tried to use the shower and toilet simultaneously, because both could not be behind a closed door at the same time.

Another logistical problem in both hotels and apartments is a toilet door that opens inward. When the toilet is small, the door almost hits the pot, making it difficult to maneuver around the door for entry and exit. Some toilets are so tiny that when sitting on the pot, the knees touch the opposite wall. In this case, it would be better to place the pot diagonally so the knees fit in a corner.

Two doors at the ends of a short corridor that both open into the corridor are impossible to open at the same time, which lengthens the time of passing through both doors.

Some hotels want to show how modern they are by replacing light switches with small touchscreens with LED backlighting. The little LED lights are numerous enough to somewhat light up the room when the ceiling and other lights are turned off. For sleeping, it would be good to be able to turn off the LED lights of the touchscreens.

If a motion detector turns on the light, then being able to switch off the motion detector and the light would be preferable. Sometimes the light is unnecessary, such as during the day with curtains open. The sudden bright light may also be annoying, for example when visiting the bathroom at night.

Hotel beds are usually short, so people over 180cm have their feet over the edge, unless they lie diagonally. Luckily hotel beds are usually wide, so their diagonal is significantly longer than the long side.

Avoiding an animal on the road

When a bike or car heads towards a squirrel, the squirrel first dodges to one side and then runs away in the other direction. Birds fly directly away from the oncoming vehicle, so stay in front of the vehicle for a few seconds. These behaviours are presumably evolutionary adaptations to avoid predators. For example, the squirrel’s dodge probably misleads a predator to alter course in the direction of the dodge. The larger predator then has more difficulty than a small agile squirrel in switching direction to the opposite side of the dodge.
In avoiding vehicles, these escape patterns are counterproductive. A predator tries to collide with the prey, but a vehicle tries to avoid collision. A squirrel’s dodge confuses the driver or cyclist, who then tries to pass the animal on the opposite side of the initial feint, which is exactly the direction the animal ends up running in. The best way to avoid collision may be to just keep going in a straight line and let the animal dodge out of the way. A constant direction and speed is easy to predict, which lets the animal avoid being in the same place at the same time as the vehicle. Keeping one’s course and speed also avoids accident-prone sharp turns and sudden stopping.
If a predator was smart and knew about the dodging behaviour, then it would go opposite the initial dodge. But then the squirrel would benefit from not switching direction. In response to the squirrel just running in one direction, the predator should run in the direction of the squirrel’s initial movement, etc. This game only has a mixed strategy equilibrium where the squirrel randomises its direction and whether it dodges or not, and the predator randomises its response to the squirrel’s initial movement direction. Dodging takes more energy than just running to one side, so the dodge must have a benefit that outweighs the energy cost, which means that the predator must be less successful when the squirrel dodges. Some factor must make it difficult for the predator to swerve opposite the squirrel’s initial direction. For example, if most prey keep running in one direction instead of feinting, then the predator may be on average more successful when following the initial movement of the prey. The cognitive cost of distinguishing squirrels from other prey must be too large to develop a different strategy for chasing squirrels.
The same game describes dribbling in soccer to avoid a defender. It would be interesting to look at data on what proportion of the time the attacker feints to one side and then moves to the other, as opposed to just trying to pass around the defender in the initial movement direction. It is more difficult for both players to switch than to keep moving in one direction, but presumably the player with the ball finds it relatively more complicated than the defender. In this case, to keep the other player indifferent, each player only has to switch direction less than half of the time, but the defender relatively less frequently. If the attacker feints and the defender does not switch direction, then the defender looks clumsy and the attacker a good dribbler. Reputation concerns of soccer players (who are after all entertainers) may make them switch direction more often than a pure winning motive would dictate.
Similarly, soccer players may use flashy moves like scissor kicks more often than is optimal for winning, because the flashiness makes the player popular with fans.

Saving ventilation cost by using the wind

Most large modern buildings have active ventilation built in, meaning that electric fans drive the air through the building. The airflow direction is usually fixed at construction time. However, if the wind happens to blow from the opposite direction to the ventilation flow, then the fans require extra energy to counter the wind. On the other hand, if the wind agrees with the airflow in the building, then the fans may not need to be run at all. To save electricity, a building could have a wind direction sensor (a weather vane) on the roof connected to a switch that reverses the ventilation fans, so that the fans always pump air in approximately the same direction as the wind. If the wind is strong enough, a wind speed sensor (a small windmill or windsock) on the roof could stop the ventilation fans altogether.
The tradeoff for this adaptive ventilation system is the initial fixed construction cost and the ongoing maintenance of the weather vane, windsock and controller of the fans. All the extra components of the system (relative to the current unidirectional ventilation) are cheap and robust, so the both the fixed cost and the maintenance should be negligible.
Current ventilation systems have differently shaped air inlets and outlets in the rooms, which suggests that the system requires a particular airflow direction. In this case, adaptive ventilation may be much more expensive than the current ones, because the ventilation shafts and air vents need to be doubled. To avoid the need to build twice as many shafts and vents, have just the air inlets and outlets of the whole building switch roles with the wind direction. The rest of the system can remain unidirectional when the valves from the building’s inlet and outlet to the rest of the system switch appropriately. The air inside the building can then move in the opposite direction of the wind some of the time. In this case, the electricity saving is only realised if the building is sufficiently airtight, which is the case for modern highrises that have unopenable windows. If the air is allowed to move through the building independently of the ventilation and the wind is opposite the airflow in the system, then the fans have to overcome the air pressure difference like in the current systems. This wastes electricity.

When to open windows to cool or warm a building

My uninsulated apartment building went from too cold to too hot in about a week, which is normal in Canberra. People have started to open the windows in the stairwell in addition to their apartment windows. The timing of the opening seems a bit misguided – people open the windows in the morning. During daytime, the air outside is warmer than the air inside the stairwell, but during the night the outside air is colder. To state the obvious: to cool down the building, open the windows for the night and close them for the day. Currently the opposite seems to happen, although I counter this trend by closing the windows in the morning when I notice them open.
In general, if you want the building cooler and the outside air is colder than the inside, then open the windows, but if the outside is warmer, then close them. If you want the building warmer and the outside air is colder than the inside, then close the windows, but if the outside is warmer, then open them. This could easily be automated with temperature sensors outside and inside the building connected to a thermostat and small electric motors opening and closing the windows. Such a system would save some of the heating and cooling costs of the building.
There may be non-temperature reasons to open and close the windows, for example to let smell out of the stairwell or to keep insects from coming in. The second reason is not relevant for my building, because all windows have bugscreens and the exterior doors have a gap an inch wide under them, which the insects can easily use to get in.