Tag: correlation

Why I can never be a great lone wolf quizzer

I admit that of late one of the unifying themes of this blog has been “correlation”. So what does that have to do with quizzing? Thing is that while I absolutely enjoy qualitative logical reasoning (which is why I still quiz actively), there is very little in common in terms of areas of interest between me and a lot of other quizzers. Specifically, unlike most other good quizzers, I have absolutely no patience for reading fiction (or “literature”), watching movies or indulging in generic American “pop culture”.

Now, it is known that a quizmaster tends to be biased in favour of the topics that he himself is good at. For example, I’ve personally found that the questions I set have more than a “fair share” of questions with a background in Economics or European Football, and nothing related to fiction, or movies. So, given that most good quizzers are good at the topics I mentioned earlier (literature, movies, pop culture), it’s likely that most quizzes will have a healthy dose of these topics. And since I know little about them, and don’t have the required levels of interest to know more about them, it’s unlikely I’ll do well in an individual quiz. Essentially, I’m at so much of a disadvantage in these heavily represented topics that it’s very tough to make up the deficit in the remainder of the quiz.

On a related note, I wonder if fashionable-ness of topics is static or dymanic. I wonder, if twenty years down the line, we’ll still find quizzes being as heavily dominated by the subjects that are in fashion today, or if there will be a new set of subjects that will be in fashion. It’s hard to say because there is positive reinforcement that is at play here. If, for example, a certain set of subjects constitutes a large portions of questions today, today’s “good quizzers” will necessarily be those that are good at these subjects. And given that the pool of quizmasters is usually drawn out of the pool of “good quizzers”, you will have more quizzes that have a large proportion of these fashionable topics. And so forth.

Again, I’m assuming here that a lot of people (unlike certain Chennai quizzers) don’t prepare for quizzes, and that they don’t try to develop interest in certain topics for the sole purpose of being good at quizzes.

The Problem With a Common Engineering Entrance Test

… is correlation and concentration.

Like everything else, a student’s performance in a test can be divided into two – the predictive component (which can be explained based on preparation levels, general intelligence, ability to handle pressure, etc.) and the random component (which includes and is not limited to illness on the day of the exam, reaching the venue late leading to unsettlement, pure luck (or the lack of it) and so on).

Now, when you have a number of exams, what you expect is for a student’s “random component” to even out across these exams. If he outperforms his “predictive component” in one exam, you would expect that he would underperform in another exam. It’s like the “predictive component” of his performance is the expected “value” of his performance.

Thus, when you have a large number of entrance exams, it gives students the opportunity for their random components to even out, and take luck out to some extent from their college admission process. When you collapse all entrance exams into one, however, a student who happens to get a large negative “random component” on that given day is denied a second chance. Thus, the college admissions process will become much more of a crapshoot than it is now.

The other thing about uniform admission standards is why should every college have the same requirements for the students it wants to recruit? Having a common exam forces this upon colleges, unless they are allowed to change their weights allocated to different sections differently. If this doesn’t happen, it’ll only end up bringing all of the country’s education system to a uniform mediocrity.

The Film Game

So today I was introduced to this “hangout game” called Film Aata (the Film Game). The rules of this game are fairly simple. Through a slightly complicated process, you pick a random letter in the alphabet. Everyone is given a certain amount of time (we played with five minutes), and in that time you need to write down as many films as possible whose names start with that letter.

It’s a fairly simple and fun (though can’t be played for too long or too often given that the number of letters in the alphabet) but what makes it interesting is the scoring system. You get points for each UNIQUE movie whose name that you have written. So basically if you’ve written down the name of a movie which at least one other person has written down, you get no points for it. So apart from knowing the names of lots of movies you need to know movies that others don’t know (and it’s useful to have a resource such as IMDB handy).

So basically correlation matters! If there is one other player in the group who has similar tastes as yours, you are bound to get screwed. For example, the two people with whom I was playing this game today are sisters, so there was a major overlap in the names of the movies that they knew, which meant that on a relative scale I performed better than I would have considering the length of my total list.

I found the game extremely interesting! Now, here is a modification that would make the game more interesting. Put a cap on the total number of movie names that a player can write, all other rules staying the same. Currently, with no limits, you will end up writing names of all movies that you can think of. There is no strategy per se involved in the game. It’s more a test of memory.

However, once we put a cap, that brings in an element of strategy to the game. Now you will need to pick and choose the movies whose names you want to put down – to choose the movies that you know other people won’t know. And in case the cap is really low, then to pick and choose the movies whose names you know others won’t write. Insane game theory scope are there!

This also makes the game more repeatable – you can play it more often with different sets of people, and each time you’ll be trying to read the minds of different people and that will make things fun. With the same set of people, you can play with different caps, giving a new strategy each time.

It’s a simple game. A kids’ game. Something that might appear to be all too simplistic on the face of it, but this simplicity allows easy innovation, and that can make the game extremely fun!

What’s your Raashee? Astrology and Vector Length

The problem with western astrology is that there are way too few categories of people according to it. Western astroogy uses a vector of length one – the part of year in which you were born in, and then concocts a story based on that. According to that, people can be classified into twelve categories (as can be seen in the great recent movie whose title is a substring of the title of this blog post) and you can tell their story based on that. Thing is that way too many people you know, and are not like you, are in the same category as you, and this makes things so much less believable.

On the other hand, the beauty of Indian astrology is the vector length that is involved with it. There are nine planets (including the Sun and the Moon, not including the Earth, and with Rahu and Ketu instead of Uranus and Neptune) and at the time of your birth, each of them can be in one of 10 houses (not sure of the number but I think this is it). There are correlation issues so the number of possible combinations isn’t as big as you think it might be, but still there are enough possible combinations that can describe each person you know uniquely!

This ability to identify almost each person uniquely is what makes Indian astrology so fascinating. Stuff is so complicated that you will never understand it. And because you will never understand it, you are more likely to believe it; unlike in western astrology where it is easy for you to see where you fit in, where things are so easy that it is easy for you to see through it.

The other thing about Indian astrology is that given the really large number of variables, it is easy for the astrologer to correct his own mistakes. He will say “Jupiter is in position 7 so X will happen” and then if X doesn’t happen he says “yeah i predicted it based on Jupiter being in 7, but then in the meantime the Sun moved into 8, and so death happened off”. It makes things so easy to cover up that it contributes to the mystique, and to the success of the art.

So a possible moral of the story is that if you want to create fraud frameworks, make sure that they involve long vectors. Make sure that you design them in such a way that the mango person won’t understand; Make sure that you build in enough variables that will allow you to cover up in case when you screw up. Make sure the vectors in your framework are long enough to make the users feel special and unique, yet giving them a feel that you’ve seen someone/something similar before.

I think this is what all the successful consulting firms have done. Perfected this art of coming up with this kind of a vector. And to think that they might have been inspired by Indian astrology..

Arranged Scissors 12 – Rejection Sharing Agreements

This is similar to the Klose-Podolski corollary to the Goalkeeper Theory. To refresh your memory, or to fresh it in case I haven’t mentioned this earlier, the Klose-Podolski corollary refers to a case of two close friends who decide to hit on the same person. The implicit understanding is that they don’t regard each other as rivals but blade together, and first get rid of all the other suitors before they engage in one last showdown so that the bladee picks one of them.

We came up with this corollary to the Goalkeeper Theory shortly after the 2006 Football World Cup, during which Klose and Podolki formed a cracking strike partnership for Germany. Later on, they were to play together for Bayerrn Munchen, but like most Klose-Podolski arrangements, they too ended up in bitterness with Poodolski (who scored the lesser number of goals among the two) publicly voicing his bitterness and finally transferring to his “native” Koln.

Now that the crazy digression is out of the way, let me get to the point. Today is the first day of Navaratri, and with the inauspicious “Mahalaya Paksha” having gotten out of the way, arranged scissors is back in full earnest. This also means that I re-enter the market, though I’m still yet to list myself (don’t plan to for a while at least. OTC is said to give superior valuations). And some casual conversation and some not-so-casual phone calls this morning, I have been thinking of the arranged marriage equivalent of the Klose-Podolski arrangement.

So basically, as part of this arrangements, two parties who are looking to hit the same side of the deal strike a deal to share “rejection information” with each other. “Rejection information” can be of the following two types:

  • Today I found out about this girl. She seems to be really good in most respects – good looking, rich, good family background, virgin and all that. But for some (usually random) reason, my son doesn’t want to marry her. Why don’t you try her for your son?
  • Today I found out about this girl. Talked to her, her parents, etc. Doesn’t seem like a good prospect at all. She is either ugly or too “forward” or her family background is bad. I think the chances of her getting along with your son is quite low. Don’t waste your time with her.

Note that both of this is extremely useful information, especially in an illiquid market. What is important here is the nature of people with whom you strike such agreements. The basic thing is that your correlation with them should neither be too low nor too high. Ideally, they should belong to the same/similar caste, should have a fairly similar family background, etc. but the boys shouldn’t be too similar. Yeah, I think that is a fair criterion – they should be as similar as possible in terms of “arranged criteria” but as different as possible in terms of “louvvu criteria”.

Basically if the correlation is too low, then you can’t really trust their judgment on counterparties. On the other hand, if the correlation is too high, then it is extremely likely that they turn out to be “rivals” and that if one party rejects a girl, it’s unlikely that the other party will like the girl. I supppose you get what I’m talking about.

One downside to such agreements that I can think of – it might cause bitterness later on in life, long after the goal has been scored. The feeling that “this guy married a girl that I rejected” or the other way round might come back to haunt you later on in life.

Bilateral Crib Arrangements and Correlation

People say that cribbing is in general good for health, and I heartily agree. I love to crib. Occasionally I bore the hell out of my listener with my cribbing. And I’m sure the readers of this blog have also been on the receiving end of this on more than one occasion. There have been occasions when I’ve been specifically asked not to crib, and others when people have tried to subtly indicate to me that they are not comfortable with my cribbing.

In order to prevent the latter problem (of boring someone with my cribs and them not being able to directly tell me to shut up), over the last few years, I’ve entered into several informal “Bilateral crib arrangements”. Ok – I’ve never used that term before – in fact, I invented that term only some two or three days back. But that doesn’t take anything away from the nature of the arrangements.

So a bilateral crib arrangement is an informal arrangement you get into where you agree to listen to someone’s cribs and lend a friendly shoulder wiht the implicit agreement that they return the favour. The terms of the arrangement are never really described in that many words but that is essentially what it is. It usually has a component where one party says “ok let’s change the subject now” or something to that effect, and the counterparty replies “no no it’s ok you can crib on”.

Occasionally I’ve also gotten into one-way arrangements – where I either only put or receive cribs, but dont’ do the opposite action. Basically this happens when one of the two parties is more comfortable with the ohter than the opposite relationship, or if one of the parties alreeady has enough crib-receivers and doesn’t need one more, but is happy to receive cribs. Though some of them have lasted, occasionally I’ve felt uncomfortable in those – assymetric relationships create mental obligations.

So coming to bilateral crib arrangements – the biggest threat to these arrangements that I’ve observed is what I call as correlation. For a bilateral crib arrangement to work effectively, it is useful if one party is in the position to receive cribs while the other wants to crib. The situation when both don’t need to crib is also good. The problem occurs if both parties want to crib and want to crib to each other.

I’ve been through this several times and it hasn’t really been pleasant. On a number of occasions, I’ve had to back down and somehow bring my cribs under control while lending a friendly shoulder to my crib-partner. On others, I’ve visibly noticed crib-partners putting up with my cribs just so as to not create conflict. Such situations are suboptimal for both parties involved, and need to be avoided.

In this regard, it is important to choose a crib partner whose correlation with you is low. That way, the chances that both of you will want to crib at the same time to each other is low, and the awkward situation of competitive cribbing or backing out can be avoided. I don’t really know how you can choose people with low correlation with you, but I supopse you’ll have to take a few data points and extrapolate. Also avoid people whose correlation with you is obviously high – such as collagues.

Another effective tool in cribpartner management is to be diversified. You need not have several bilateral crib arrangements, but with a judicious combination of unidirectional and bidirectional crib arrangements, keeping in mind various time zones, you can ensure that there is a receiver to listen to you whenever you want to crib.

Arranged Scissors 8: Culture fit with parents

That you are in the arranged marriage process means that your parents now have full veto power over whom you marry. Given that you don’t generally want them to veto someone whom you have liked, the most common protocol as I understand is for parents to evaluate the counterparty first, and the “candidate” to get only the people who have passed the parental filter. Then the “candidates” proceed, and maybe meet, and maybe talk, and maybe flirt and maybe decide to get married.

Hypothesis: The chance of your success in the arranged marriage market is directly proportional to the the culture fit that you have wtih your parents.

Explanation: Given that parents have veto power in the process, and given the general protocol that most people follow (which I have described in the first para above; however, it can be shown that this result is independent of the protocol), there are two levels of “culture fit” that an interested counterparty has to pass. First, she has to pass the candidate’s parents’ culture fit test. Only after she has passed the test does she come in contact with the candidate (in most cases, not literally).

Then, she will have to pass the candidate’s culture fit test. By the symmetry argument, there are two more such tests (girl’s parents’ filter for boy and girl’s filter for boy). And then in the arranged marriage setting, people tend to evaluate their “beegaru” (don’t think english has a nice phrase for this – basically kids’ parents-in-law). So you have the boy’s parents evaluating the girl’s parents for culture fit, and vice versa.

So right at the beginning, the arranged marriage process has six layers of culture fit. And even if all these tests are passed, one gets only to the level of the CMP. (given that very few filter down to this level, i suppose a lot of people put NED at this stage and settle for the CMP).

Without loss of generality, let us now ignore the process of boy’s parents evaluating girl’s parents and vice versa (the problem is complex enough without this). So there are basically four evaluations, made by two pairs of evaluators (let us consider parents as one entity – they might have difference in opinion between each other occasionally but to the world they display a united front). Now for each side it comes down to the correlation of expectations between the side’s pair of evaluators.

The higher the “culture fit” you possess with your parents, the higher the chance that you will agree with them with regard to a particular counterparty’s culture fit. And this chance of agreement about culture fit of counterparty is directly proportional to the chance of getting married through the arranged marriage process (basically this culture fit thing can be assumed to be independent of all other processes that go into the arranged marriage decision; so take out all of those and the relationship is linear). Hence proved.

Now what if you are very different from your parents? It is very unlikely that you will approve of anyone that they will approve of, and vice versa. In such a situation it is going to be very hard for you to find someone through the arranged marriage process, and you are well advised to look outside (of course the problem of convincing parents doesn’t go away, but their veto power does).

So the moral of the story is that you should enter the arranged marriage market only if you possess a reasonable degree of culture fit with your parents.

(i have this other theory that in every family, there is a knee-jerk generation – one whose “culture” is markedly different compared to that of its previous generation. and after each knee-jerk, cultural differences between this generation and the following few generations will be low. maybe i’ll elaborate on it some other time)

Arranged Scissors 1 – The Common Minimum Programme

Arranged Scissors 2

Arranged Scissors 3 – Due Diligence

Arranged Scissors 4 – Dear Cesare

Arranged Scissors 5 – Finding the Right Exchange

Arranged Scissors 6: Due Diligence Networks

Arranged Scissors 7: Foreign boys

Intellectual Property

A blog post earlier this month on Econlog finished off with a very strong quote by Friedrich Hayek:

One of the forms of private property that people cherish most is their ideas. If you convince them that their ideas are wrong, you have caused them to suffer a capital loss.

I ended up liking it so much that I added it to my work email signature. Thinking about it further, why is it that some people are more open to debate than others? Why do some people admit to their mistakes easily while others are dogmatic about them? Why do some people simply refuse to discuss their ideas with other people? I think Hayek’s observation offers a clue.

Let us consider two people – Mr. Brown and Mr. Green. Mr. Brown believes in diversification, and his investments are spread across several financial instruments, belonging to different categories, with a relatively small amount of money in each of them. For purposes of this analogy, let us assume that no two instruments in his portfolio are strongly correlated with each other (what is strong correlation? I don’t know. I can’t put a number on it. But I suppose you get the drift)

Mr. Green on the other hand has chosen a few instruments and has put a large amount of money on each of them. It is just to do with his investment philosophy, which we shall not go into, as this is just an analogy.

Let us suppose that both Mr. Brown and Mr. Green held Satyam stock on 6th January 2009. They were both invested in Satyam according to their respective philosophies – and the weightage of Satyam in their respective portfolios was also in line with their philosophies. The next day, 7th of January, the Satyam fraud came out. The stock crashed to a tenth of its value. Almost went to zero. How would our friends react to this situation?

Mr. Green obviously doesn’t like it. A large part of his investments has been wiped out. He has become a significantly poorer man. For a while he will be in denial about this. He will refuse to accept that such a thing could happen to one of his chosen stocks. He will try to convince himself that this fall (a 90% fall, no less) is transient, and the stock will go back to where it once was. As days go by, he realizes that his investments have been lost for ever. He is significantly poorer.

Mr. Brown will also be disappointed by the fall – after all, he too has lost money in the fall. However, his disappointment is mitigated by the fact that the loss is small compared to his portfolio. There have been other stocks in his portfolio which have been doing well, and their performance will probably absorb the Satyam losses. Some of the stocks in his portfolio may also be fundamentally negatively correlated with Satyam, which means they will now gain. There is also the possibility that the Satyam fall has opened up some new possible areas of investment for Mr. Brown, and he might put money into them. It is much easier for Mr. Brown to accept the fall of Satyam compared to Mr. Green.

So you replace stocks by ideas, and I suppose you konw what I am gettting at. The degree of openness that people show with respect to an idea they have varies inversely with the share of this particular idea in their “idea portfolio”. The smaller the proportion of this idea, the lesser will be the “capital cost” of their losing the idea. And hence, they will be more open to debate, to discussion, to letting someone critically examine their ideas. If the proportion of this particular idea in their overall portfolio is large, there will obviously be resistancce.

A corrolary of this is that when someone possesses a small number of ideas they are more likely to be dogmatic about them (I am using the indefinitive “more likely” here because even when you have a small number of securities in your portfolio, your exposure to some of them will be really small and so you’ll be less unwilling to lose them. Though I must point out that people with small ideas portfolios become so used to madly defending the big ideas in the portfolio that they start adopting the same tactic for the smaller ideas in their portfolio and become dogmatic about them – which is irrational).

I just hope I didn’t cause you a capital loss by writing this. For me, on the other hand, this was a bonus stock.