Category: arbit

Known stories and trading time

One of the most fascinating concepts I’ve ever come across is that of “trading time”. I first came across it in Benoit Mandelbrot’s The (Mis)Behaviour of Markets, which is possibly the only non-textbook and non-children’s book that I’ve read at least four times.

The concept of “trading time” is simple – if you look at activity on a market, it is not distributed evenly over time. There are times when nothing happens, and then there are times when “everything happens”. For example, 2020 has been an incredibly eventful year when it comes to world events. Not every year is eventful like this.

A year or so after I first read this book, I took a job where I had to look at intra-day trading in American equities markets. And I saw “trading time” happening in person – the volume of trade in the market was massive in the first and last hour, and the middle part of the day, unless there was some event happening, was rather quiet.

Trading time applies in a lot of other contexts as well. In some movies, a lot of action happens in certain times of the movie where nothing happens in other times. When I work, I end up doing a lot of work in some small windows, and nothing most of the time. Children have “growth spurts”, both physical and mental.

I was thinking about this topic when I was reading SL Bhyrappa’s Parva. Unfortunately I find it time-consuming to read more than a newspaper headline or signboard of Kannada, so I read it in translation.

However, the book is so good that I have resolved to read the original (how much ever time it takes) before the end of this year.

It is a sort of retelling of the Mahabharata, but it doesn’t tell the whole story in a linear manner. The book is structured largely around a set of monologues, largely set around journeys. So there is Bhima going into the forest to seek out his son Ghatotkacha to help him in the great war. Around the same time, Arjuna goes to Dwaraka. Just before the war begins, Bhishma goes out in search of Vyasa. Each of these journeys associated with extra long flashbacks, and philosophical musings.

In other words, what Bhyrappa does is to seek out tiny stories within the great epic, and then drill down massively into those stories. Some of these journey-monologues run into nearly a hundred pages (in translation). The rest of the story is largely glossed over or given only a passing mention to.

Bhyrappa basically gives “trading time treatment” to the Mahabharata. It helps that the overall story is rather well known, so readers can be expected to easily fill in any gaps. While the epic itself is great, there are parts where “a lot happens”, and parts where “nothing happens”. What is interesting about Parva is that Bhyrappa picks out unintuitive parts to explore in massive depth, and he simply glosses over the parts which most other retellings give a lot of footage to.

And this is what makes the story rather fascinating.

I can now think of retellings of books, or remakes of movies, where the story remains the same, but “trading time is inverted”. Activities that were originally given a lot of footage get glossed over, but those that were originally ignored get explored in depth.

 

Scrabble

I’ve forgotten which stage of lockdown or “unlock” e-commerce for “non-essential goods” reopened, but among the first things we ordered was a Scrabble board. It was an impulse decision. We were on Amazon ordering puzzles for the daughter, and she had just about started putting together “sounds” to make words, so we thought “scrabble tiles might be useful for her to make words with”.

The thing duly arrived two or three days later. The wife had never played Scrabble before, so on the day it arrived I taught her the rules of the game. We play with the Sowpods dictionary open, so we can check words that hte opponent challenges. Our “scrabble vocabulary” has surely improved since the time we started playing (“Qi” is a lifesaver, btw).

I had insisted on ordering the “official Scrabble board” sold by Mattel. The board is excellent. The tiles are excellent. The bag in which the tiles are stored is also excellent. The only problem is that there was no “scoreboard” that arrived in the set.

On the first day we played (when I taught the wife the rules, and she ended up beating me – I’m so horrible at the game), we used a piece of paper to maintain scores. The next day, we decided to score using an Excel sheet. Since then, we’ve continued to use Excel. The scoring format looks somewhat like this.

So each worksheet contains a single day’s play. Initially after we got the board, we played pretty much every day. Sometimes multiple times a day (you might notice that we played 4 games on 3rd June). So far, we’ve played 31 games. I’ve won 19, Priyanka has won 11 and one ended in a tie.

In any case, scoring on Excel has provided an additional advantage – analytics!! I have an R script that I run after every game, that parses the Excel sheet and does some basic analytics on how we play.

For example, on each turn, I make an average of 16.8 points, while Priyanka makes 14.6. Our score distribution makes for interesting viewing. Basically, she follows a “long tail strategy”. Most of the time, she is content with making simple words, but occasionally she produces a blockbuster.

I won’t put a graph here – it’s not clear enough. This table shows how many times we’ve each made more than a particular threshold (in a single turn). The figures are cumulative

Threshold
Karthik
Priyanka
30 50 44
40 12 17
50 5 10
60 3 5
70 2 2
80 0 1
90 0 1
100 0 1

Notice that while I’ve made many more 30+ scores than her, she’s made many more 40+ scores than me. Beyond that, she has crossed every threshold at least as many times as me.

Another piece of analysis is the “score multiple”. This is a measure of “how well we use our letters”. For example, if I start place the word “tiger” on a double word score (and no double or triple letter score), I get 12 points. The points total on the tiles is 6, giving me a multiple of 2.

Over the games I have found that I have a multiple of 1.75, while she has a multiple of 1.70. So I “utilise” the tiles that I have (and the ones on the board) a wee bit “better” than her, though she often accuses me of “over optimising”.

It’s been fun so far. There was a period of time when we were addicted to the game, and we still turn to it when one of us is in a “work rut”. And thanks to maintaining scores on Excel, the analytics after is also fun.

I’m pretty sure you’re spending the lockdown playing some board game as well. I strongly urge you to use Excel (or equivalent) to maintain scores. The analytics provides a very strong collateral benefit.

 

Half-watching movies, and why I hate tweetstorms

It has to do with “bit rate”

I don’t like tweetstorm. Up to six tweets is fine, but beyond that I find it incredibly difficult to hold my attention for. I actually find it stressful. So of late, I’ve been making a conscious effort to stop reading tweetstorms when they start stressing me out. The stress isn’t worth any value that the tweetstorms may have.

I remember making the claim on twitter that I refuse to read any more tweetstorms of more than six tweets henceforth. I’m not able to find that tweet now.

Anyways…

Why do I hate tweetstorms? It is for the same reason that I like to “half-watch” movies, something that endlessly irritates my wife. I has to do with “bit rates“.

I use the phrase “bit rate” to refer to the rate of flow of information (remember that bit is a measure of information).

The thing with movies is that some of them have very low bit rate. More importantly, movies have vastly varying bit rates through their lengths. There are some parts in a movie where pretty much nothing happens, and a lot of it is rather predictable. There are other parts where lots happens.

This means that in the course of a movie you find yourself engrossed in some periods and bored in others, and that can be rather irritating. And boredom in the parts where nothing is happening sometimes leads me to want to turn off the movie.

So I deal with this by “half watching”, essentially multi tasking while watching. Usually this means reading, or being on twitter, while watching a movie. This usually works beautifully. When the bit rate from the movie is high, I focus. When it is low, I take my mind off and indulge in the other thing that I’m doing.

It is not just movies that I “half-watch” – a lot of sport also gets the same treatment. Like right now I’m “watching” Watford-Southampton as I’m writing this.

A few years back, my wife expressed disapproval of my half-watching. By also keeping a book or computer, I wasn’t “involved enough” in the movie, she started saying, and that half-watching meant we “weren’t really watching the movie together”. And she started demanding full attention from me when we watched movies together.

The main consequence of this is that I started watching fewer movies. Given that I can rather easily second-guess movie plots, I started finding watching highly predictable stuff rather boring. In any case, I’ve recently received permission to half-watch again, and have watched two movies in the last 24 hours (neither of which I would have been able to sit through had I paid full attention – they had low bit rates).

So what’s the problem with tweetstorms? The problem is that their bit rate is rather high. With “normal paragraph writing” we have come to expect a certain degree of redundancy. This allows us to skim through stuff while getting information from them at the same time. The redundancy means that as long as we get some key words or phrases, we can fill in the rest of the stuff, and reading is rather pleasant.

The thing with a tweetstorm is that each sentence (tweet, basically) has a lot of information packed into it. So skimming is not an option. And the information hitting your head at the rate that tweetstorms generally convey can result in a lot of stress.

The other thing with tweetstorms, of course, is that each tweet is disjoint from the one before and after it. So there is no flow to the reading, and the mind has to expend extra energy to process what’s happening. Combine this with a rather high bit rate, and you know why I can’t stand them.

Bad Apples

Nowadays, I keep apples in the fridge. Apart from remaining fresh longer, I like eating cold apples as well.

It wasn’t always this way. And I would frequently encounter what I call the “bad apples” problem.

You have a bunch of apples at home. They get a little overripe. You don’t want to eat them. You go to the market and see fresh apples there, but you know that you have apples at home. Because you have apples at home, you don’t want to buy new ones. But you don’t want to eat the apples at home, because they are too ripe.

And so they just sit there, getting progressively worse by a wee bit every day. Seeing them everyday makes you feel bad about having not finished them, but also reminds you to not buy new apples. And so you go days together without eating any apples, until one day you gather the courage to throw them in the bin and buy new apples.

I’ve become conscious of this problem for a lot of foodstuff. Apples, as I told you, I now keep in the fridge, so they last longer. The problem doesn’t fully go since you can have months-old wrinkly apples sitting in your fridge that you don’t want to eat, and which prevent you from buying new ones in the market. However, it is far better than seeing apples rot on the shelf.

Bananas and oranges offer the benefit that as soon as they are overripe, they make for excellent smoothies and juices respectively. I’ve become particular about finishing them off that way. Mangoes can be juiced/milkshaked as well. And I’ve developed processes around a lot of foodstuff now so that this “bad apples” problem doesn’t happen.

However, there is no preventing this problem from occurring elsewhere. Books is a prominent example. From this excellent interview of venture capitalist Marc Andreessen that I’m reading:

The problem of having to finish every book is you’re not only spending time on books you shouldn’t be but it also causes you to stall out on reading in general. If I can’t start the next book until I finish this one, but I don’t want to read this one, I might as well go watch TV. Before you know it, you’ve stopped reading for a month and you’re asking “what have I done?!”

It happens with work. There might be a half-written blogpost that you’re loathe to finish, but which prevent you from starting a new blogpost (I’ve gotten pretty ruthless at deleting drafts. I prefer to write posts “at one shot”, so this isn’t that much of a pain).

The good thing, though, is that once you start recognising the bad apples problem in some fields (such as apples), you start seeing them elsewhere as well. And you will develop policies on dealing with them.

Now I’m cursing myself for setting myself an annual target of “number of books to read” (on Goodreads). It’s leading to this:

the sunk cost fallacy means that I try harder to finish so that I can add to my annual count. Sometimes I literally flip through the pages of the book looking for interesting things, in an attempt to finish it one way or the other

Bad apples aren’t that easy to get rid of!

 

Famous people from little-known countries

I recently finished reading Svetlana Alexievitch’s Second-hand Time, a memoir of people in the erstwhile Soviet Union as the union broke down in 1991. It’s a long and rather intense book, and maybe it wasn’t the best choice for reading on days when I wasn’t able to sleep.

I don’t, however, regret reading the book at all. It was incredibly enlightening and taught me a lot of life in the Soviet Union and in the post-Soviet republics. This is what I wrote in review on Goodreads:

Absolutely brilliant book. Very very informative and enlightening, especially for someone for whom “USSR” was this monolith growing up, and then finding out that it was actually 15 different countries.

Only reasons I didn’t give it 5 stars are that it’s a bit too long (though at no point did I want to give up on the book – it’s very good), and that some of the stories are a bit too similar.

Also I would have preferred more stories from the non-Russian republics.

One of the stories in the book is about migrant workers from Tajikistan in Moscow, and how they are ill-treated and racially abused. They are called “blackies”, for example, a term that puzzled me since to my knowledge Tajiks are rather fair-skinned.

I had to “see it to believe it”, and what did I do? I googled the photo of perhaps the only Tajik I’ve heard about – Ahmed Shah Massoud, late leader of the Northern Alliance who fought in the early 2000s to expel the Taliban from Afghanistan.

(Now I learn that Massoud was Afghan and not Tajik, so I was actually mistaken. I somehow remember him as being the leader of the ethnic Tajiks in the battle against the Taliban (and General Abdul Rashid Dostum being an ethnic Uzbek leader as part of the Northern Alliance) ).

In any case, now that it turns out that Ahmad Shah Massoud wasn’t actually Tajik, it turns out that I don’t know of even a single Tajik. Not one. So this got me thinking about countries that have very few people who are present in popular imagination.

And I don’t think there are too many countries from where there are so few little-known people (I consider my own “general knowledge” to be pretty good, so me knowing someone “famous” from a country should count).

Some countries have charismatic or otherwise popular political leaders, and you are likely to know them by face. Then, there is sport – if you follow a handful of sports, you are likely to know at least a few people from most countries.

For example, my ability at guessing a European’s nationality from their first name comes from my following of football, a sport that is popular all over Europe, and has famous players pretty much from all countries (I admit I don’t know anyone from Moldova or Belarus, though the latter has a rather famous and nicely named football club).

I know of people from a lot of former Soviet republics (but not any Tajiks, or Uzbeks or Kazakhs) because I follow chess. Paul Keres from Estonia, Mikhail Tal from Latvia, Levon Aronian and Tigran Petrosian from Armenia, Teimour Rajdabov and Shakhryar Mamedyarov from Azerbaijan and so on are among the very few (or only) people I know from their respective countries.

Think about it – which are the countries from which you can’t name a single person? How many such countries might there be? In my case there may be a maximum of 50 such countries (there are about 200 independent countries in the world, IIRC).

I recently came across this blog post in EconLog which made a pretty interesting point comparing blacks in the US to Uighurs in China, which possibly prompted my post:

In most cases, oppressed groups tend to be relatively poor and powerless, and thus are often invisible to outsiders. Can you name a single member of the Uyghur minority in China?

It seems to me that African-Americans are somewhat different. Correct me if I’m wrong, but aren’t most well informed people in other countries able to name and identify quite a few African-Americans? In politics the most obvious example is Barack Obama…

I can’t think of a single Uyghur either. Oh, and I forgot to mention the role of movies and books and other methods of popular culture that give you exposure to people from different countries.

Mata Amrita Goes To New York Times

Remember that I had written recently that the pandemic is likely to change the practice of hugging, and the Mata Amrita Index? Now the New York Times has also covered it (possibly paywalled). It includes helpful graphics on “how to hug and how not to hug”.

It is an interesting article, quoting an expert on aerosols about what is the best way to hug. From what I gather, the key is to keep your faces turned away from each other. As long as you maintain this, hugging should still be fine.

[…] the safest thing is to avoid hugs. But if you need a hug, take precautions. Wear a mask. Hug outdoors. Try to avoid touching the other person’s body or clothes with your face and your mask. Don’t hug someone who is coughing or has other symptoms.

And remember that some hugs are riskier than others. Point your faces in opposite directions — the position of your face matters most. Don’t talk or cough while you’re hugging. And do it quickly. Approach each other and briefly embrace. When you are done, don’t linger. Back away quickly so you don’t breathe into each other’s faces. Wash your hands afterward.

Most of this seems fine. Only the last bit seems a bit difficult to implement – how do you wash your hands soon after hugging someone without offending them? I mean – I face this problem already. There are many people I come across whose hands I shake (this is all pre-pandemic) which leave me queasy and at unease until I have washed my hands. The challenge in this situation is how to efficiently wash your hands without making it explicit that the handshake wasn’t a pleasant one.

My favourite bit in the article, however, is the last one. It pertains to the “quality of hugs” that I’ve been talking about for a while now, and also happens to bring in Marie Kondo into the picture.

Dr. Marr noted that because the risk of a quick hug with precautions is very low but not zero, people should choose their hugs wisely.

“I would hug close friends, but I would skip more casual hugs,” Dr. Marr said. “I would take the Marie Kondo approach — the hug has to spark joy.”

Local time zones and function food

Last year after we got back to Bangalore from London, we started inviting people home for meals. It gave us an opportunity to socialise and rebuilt our network here. However, soon we stopped doing this – we had what I call a “time zone problem”.

In the UK, people eat early, and kids go to bed early. We liked both these aspects of the British culture and (to the extent possible) adopted them wholeheartedly. Now, back in India, we continue to follow these practices, but realise that most people around us don’t follow it. And this results in “time zone issues”.

This inevitably results in crane-fox situations when we have to go to someone’s place to eat or vice versa. We have gotten foxed several times, turning up for dinner at 630 or 7, and staying hungry till 9. We’ve tried craning several times, calling people at home for dinner at 630 or 7, and having them turn up much later in the evening.

Meeting outside in neutral places has some mitigating factors. Like 8pm drinks with friends means I finish my dinner and then go for drinks, thus maintaining my schedule. When I want to avoid drinking, the easiest thing to do is to drive to the venue (I’m paranoid about driving without full control).

The worst are religious functions. I’m pretty sure I’ve cribbed about them several time here on this blog. With very few exceptions, they invariably serve lunch or dinner late. Also that a “sacred event” is going on is reason enough for most other guests to not be bothered about the disruptions in eating schedules.

And to deal with that (apart from the fact that a large number of functions after we returned to India served pretty unspectacular food), we took inspiration from a close relative who has this policy of never eating at functions (the one time he broke this policy, two years ago, also coincided with what is easily the worst wedding food I’ve ever eaten, so it’s unlikely he’s breaking his policy again). Unless we have good reason to believe that the food at a function is going to be good (most reliable indicator being the caterer), we’ve taken to this relative’s policy.

Timing of most events in Bangalore means that we can eat our food at our normal times (lunch at noon, dinner at 6:30) and then comfortably get to the function well in time. Sometimes the host might get offended when we don’t eat, so a lighter than usual meal at home ensures that there is room for at least a dessert and a tiny course of meal.

As for the original crane-fox situation (calling people home or visiting for meals), we’ve started making adjustments. A few months after we returned, the daughter got back to her usual schedule of going to bed at 7 (unlike most children her age, she doesn’t nap in the afternoon). So dinner invites (in either direction) are out of the question. Lunch invites we manage by adjusting our breakfast times and quantities.

What’s the use of living in India if you cut yourself off from all socialising?

I don’t know which 80%

Legendary retailer John Wanamaker (who pioneered fixed price stores in the mid 1800s) is supposed to have said that “half of all advertising is useless. The trouble is I don’t know which half”.

I was playing around with my twitter archive data, and was looking at the distribution of retweets and favourites across all my tweets. To say that it follows a power law is an understatement.

Before this blog post triggers an automated tweet, I have 63793 tweets, of which 59,275 (93%) have not had a single retweet. 51,717 (81%) have not had a single person liking them. And 50, 165 (79%) of all my tweets have not had a single retweet or a favourite.

In other words, nearly 80% of all my tweets had absolutely no impact on the world. They might as well have not existed. Which means that I should cut down my time spent tweeting down to a fifth. Just that, to paraphrase Wanamaker, I don’t know which four fifths I should eliminate!

There is some good news, though. Over time, the proportion of my tweets that has no impact (in terms of retweets or favourites – the twitter dump doesn’t give me the number of replies to a tweet) has been falling consistently.

Right now, this month, the score is around 33% or so. So even though the proportion of my useless tweets have been dropping over time, even now one in every tweets that I tweet has zero impact.

My “most impactful tweet” itself account for 17% of all retweets that I’ve got. Here I look at what proportion of tweets have accounted for what proportion of “reactions” (reactions for each tweet is defined as the sum of number of retweets and number of favourites. I understand that the same person might have been retweeted and favourited something, but I ignore that bit now).

Notice how extreme the graph is. 0.7% of all my tweets have accounted for 50% of all retweets and likes! 10% of all my tweets have accounted for 90% of all retweets and likes.

Even if I look only at recent data, it doesn’t change shape that much – starting from January 2019, 0.8% of my tweets have accounted for 50% of all retweets and likes.

This, I guess, is the fundamental nature of social media. The impact of a particular tweet follows a power law with a very small exponent (meaning highly unequal).

What this also means is that anyone can go viral. Anyone from go from zero to hero in a single day. It is very hard to predict who is going to be a social media sensation some day.

So it’s okay that 80% of my tweets have no traction. I got one blockbuster, and who knows – I might have another some day. I guess such blockbusters is what we live for.

Facial appendages

Designers and manufacturers of things we wear on our face don’t seem to have taken into account the fact that people can wear multiple facial appendages at a time.

One problem that has bothered me since I was eighteen, when I got my first motorcycle, has been the clash between my spectacles (something I’ve worn since I was eight) and the full-face helmet. Design of full-face helmets has always meant that I’ve had to take the spectacles off, wear the helmet and then wear the specs back on (and then put on the visor of the helmet).

With some helmets it’s worked beautifully. But occasionally I’ve bought helmets one size too small (or borrowed my wife’s helmet), and in those cases this correlation hasn’t worked out well. There are days when I wear contact lenses first thing in the morning just because I need to take the scooter out.

And now, there is a third appendage which doesn’t work well with either the spectacles or the helmet – the facial mask to keep covid-19 germs away.

So far I’ve been completely unable to wear a helmet while not making the mask move out of position (this is irrespective of which helmet and which mask I use).

And most of my masks have not worked well with my spectacles as well. They interfere with each other in several places – on the nose, on the ears, vapours from the mask fogging up my spectacles. I might start wearing my contact lenses first thing in the morning now as well, just so that I can wear a mask when I step out.

Now imagine what it would be like to wear spectacles, mask and helmet all at once.

I’m glad my hearing is good, for I’m sure you won’t be able to imagine what it’s like to wear spectacles, mask, helmet and hearing aids.

PS: I discovered this morning that I’m allergic to the N95 mask I have. It has an appendage to make it fit well on the nose, and my nose has developed rashes from it.

Mata Amrita in the time of Covid-19

You remember the Mata Amrita Index? I’d first defined it in early 2009, and it is broadly defined as “the likelihood that you will hug a randomly chosen friend or acquaintance you meet”. There is a bilateral version as well, which is defined as “the likelihood that a given pair of people will hug each other when they meet”.

I’ve revisited this concept several times on this blog. Once, I had wondered how you can go about “changing your MAI” with someone. On another occasion I had tried to add a quality dimension to the index, to account for the “quality of hugs”. But indices in general don’t do well when you try to complicate them too much.

In any case, I’ve been wondering how people’s MAI will evolve given the covid-19 crisis. I also wonder how the quality-adjusted MAI will evolve.

For one, Mumbai Mirror reports that Mata Amrita (in whose honour the index has been named) herself has been badly affected by the crisis.

“Like everywhere in the world, life in Kerala and the ashram have changed,” says the ‘hugging saint’, Mata Amritanandamayi, known to her devotees as ‘Amma’, over email. “This is the first time in more than 45 years that there has been no darshan.”

The crisis automatically means that we will, to the extent possible, try to avoid physical contact with other people. When shaking hands itself is frowned upon, hugs are out of the question. However, there will be people outside your immediate family with whom you would have developed a high bilateral MAI. How do you deal with them once you start meeting them again?

My guess is that the bilateral MAI will get sharply partitioned, and “collapse” (in a Schrödingerian sense). For people with whom you’ve had a high historical MAI, and where the historical quality has also been high, you are likely to take a “hell with the virus” approach and continue the (high quality) hugs.

Among other things these also tend to be the people you trust very well (why would you hug someone tightly if you don’t trust them?), and also there aren’t likely to be very many of them.

At the other end, anyone for whom historical bilateral MAI is not close to 1, or with whom the historical quality of hugs hasn’t been great, you’ll simply eschew the hug, going all the way to the namaste, maybe.

So all these “polite hugs” will disappear (which isn’t a bad thing at all, in my opinion). People will also feel less queasy about rejecting a hug – now they have a very good reason to do so.

The other thing is that you need a sort of “trust jump” with someone to get to a point where your MAI jumps from 0 to 1. The old progression (which was never a continuous progression) from handshake to side hug to quick hug to full hug is not going to be valid any more, as you need to directly jump from a zero MAI to a high quality one MAI.

Finally, what will happen of Mata Amrita herself? Is the dip in her “darshan” a temporary impact or a permanent impact? I suspect it’s the former?