Econstudentlog

A game

US – Karl Johan Rist (server elo: 1769), 10 min blitz, closed Ruy Lopez:

1. e4 …e5
2. Nf3 …Nc6
3. Bb5 …a6
4. Ba4 …Nf6
5. 0-0 …b5
6. Ba3 …Be7
7. c3 …d6
8. h3 …Na5
9. Bc2 …c5
10. d4 …Qc7

chess

(…no comments on any of the above moves, this is all theory…)

11. Be3? (I’ve actually made this mistake before, but apparently I don’t learn from my mistakes. The move played is a stupid move that loses a tempo and is an open invitation to a draw, as I have no intention of letting the bishop be exchanged on e3. To play a4 here is probably the option I like best in retrospect – I don’t like d5, even if that e4-d5 pawn setup has become somewhat popular these days) …Nc4
12. Bc1 …Bd7
13. a4 …0-0
14. B3 …Na5
15. Bd2 …Rfc8

chess1

16. Na3 …cxd4
17. cxd4 …bxa4
18. bxa4 …Nc4
19. Nxc4 …Qxc4
20. Bb3 …Qd3

chess2

21. dxe5 …dxe5? (Nxe4 is the only move)
22. Nxe5 …Qxe4
23. Re1

chess3

(The position is still materially equal here, so some people might think that 21…dxe5 is ok: It isn’t, fritz is already at appr. +2.00 here. Fritz also likes 23.Bxf7+ – after which white is up a pawn and a quality, which is more than enough for a win even if a lot of pawns have been exchanged already: 23…Kh8(/f8), 24.Re1…Qd4(/Qb7), 25.Nxd7…Qxd7, 26.Be6:

chess6

…of course followed by 27.Bxc8. Strictly speaking, given black’s response to Re1 this variation could still have been played in the game – the move order wrt. the bishop and the rook is irrelevant given the fact that black played 23…Qb7 – but I didn’t look too hard for it, and I had already pretty much convinced myself that taking with the knight on f7 was objectively stronger than taking with the bishop. It isn’t, given optimal play by black)

23…Qb7 (…Qd4 is stronger, but black is still in deep trouble, ie. 24.Bxf7+ …Kf8, 25.Qe2 …Bd6, 26.Nxd7+ …Kxf7, 27.Qd6+…Kg6)
24. Nxf7 …Bxh3?? (a horrible move that loses instantly. Kf8 had to be tried, but even with correct play this position is just lost for black)

chess4

25.Nd6+! …Kh8
26.Nxb7 …Rab8?
(Bg4 is better but nothing can save this position)
27.Rxe7

chess5

…resigned,

1-0

Btw. Ivanchuk and Navarra is playing a rapid match at the moment in Prague. The timecontrol is 25 minutes plus 5 seconds per move, so most games last less than an hour. Ivanchuk is, despite his very poor performance in Sofia, ahead 3-1. Half of the games have been played. You can follow the games live at the official site here. Here you can find analyses of the games using what I assume is the most recent version of Rybka, a very strong chess program.

May 29, 2009 Posted by | Chess | Leave a comment

Martin Hellman’s take on the risk of nuclear war

I’m sure some of you have already seen it, and I know I am late to the party as both marginalrevolution and freakonomics have already mentioned it and linked to it, but I never got around to linking to it from this blog, even if I found it somewhat interesting when I watched it more than a week ago, a mistake I now shall correct:

Even if the title of the presentation/video is: “Soaring, Cryptography and Nuclear Weapons”, he spends probably 45 minutes talking about nuclear weapons, so that is really what the whole presentation is about. The first 8 minutes or so on soaring is related to his talk on nuclear weapons, and I would advise you to watch it all. You can read a paper closely related to the talk here, if you prefer a written version from a video and don’t have an hour to spare (you should be able to read the paper in a significantly shorter amount of time than it takes to watch the presentation).

A few selected main points:

i) Problems related to high impact low probability events are easily overlooked and/or ignored due to ie. framing and status quo bias (that’s just another way to state what he’s trying to say in the beginning with his 99,9 % safe maneuver).

ii) You need units of time on your risk assessments. And not only because risk factors change over time. The concept of compounded risk is important, and often overlooked.

iii) Status quo bias is very important when explaining the nuclear policy of countries with nuclear weapons. As Hellman states about the US experience: Even minor changes in our nuclear weapons posture have been rejected as too risky even though the baseline risk of our current strategy had never been estimated. (what does this argument, if it is valid, btw. tell us about the sustainability path of the current state of affairs in the long run?)

…which leads us to…

iv) This risk is not well understood, and very difficult to assess – and nobody really seem to care about it much.

v) There are many different ways nuclear weapons can be used today, both when it comes to warfare and -terror. Some scenarios lead us to a state we can return from again; others do not. Close monitoring of early warning signs is critical when it comes to risk assessment and -prevention of this problem.

The recently conducted North Korean nuclear weapon test was one of the warning signs mentioned above, and it sure as *** did not decrease the risk of nuclear weapons being used somewhere in the future.

More general comments: I would say I think Hellman overestimates the risk, but I’m also pretty sure I think most people underestimate it, and/or don’t think about it at all. Also, I’m not so sure this risk is either as assessable or as preventable as Hellman believes. But, I must add, I do not think that the fact that the risk is not easy to properly estimate, is a weighty argument against trying much harder than we do today to do so. Last, compounded risk is important, but it’s also a problematic concept to use when forecasting and designing long run estimates, precisely because risk factors change a lot over time: The risk of nuclear war was zero 80 years ago, but that fact is irrelevant today. Yes, you can weigh the data in the model so that risk in recent periods weigh higher than risk many decades ago, but it’s not clear that this is the best approach (in a crisis, a near miss 40 years ago would provide better information on how to act – or on how not to act – during the crisis than the risk assessment ten years ago, and the actions undertaken then, where nothing out of the ordinary happened) – maybe it would be better to weigh annual data according to the risk of the specific year, so that the actions undertaken in relative high-likelihood neighborhoods (near-misses) will be better taken into account? Maybe a combination, and maybe seven other variables should be included? No matter how you weigh the data, you’re gonna have problems knowing what to do in a bad situation, even if you knew the proper risk model and distribution of the data, which you most certainly don’t. If people don’t think long and hard about this before something ugly pops up somewhere down the line – and the default position here would probably be that the fact that some people did think long and hard about this for some time would decrease the chance of “something ugly” eventually popping up – there’s a lot of stuff that needs to be done in a very short amount of time, and that is a recipe for disaster. As Hellman makes it clear in his presentation, the “do/think-very-little” seems to be the current state of affairs, seeing as no one so far has even made an attempt to quantify the risk we’re facing.

Oh yes, one thing I forgot: In my mind, the risk of nuclear weapons being used is not on a path of uniform motion, where the absolute risk of one or more nuclear bombs being used somewhere increases over time at a steady pace, whereas the annual risk is fixed. I think the absolute risk in the long run is accelerating, that is, the risk of a bomb going off increases over time and gets bigger every year. This is related to the fact that I do not consider the most relevant metric, when it comes to the risk of a nuclear bomb being used, to be the number of weapons available in the world, but rather the number of relatively autonomous agents each having at least one – and that number has only gone up since the first nuclear test was conducted.

May 28, 2009 Posted by | nuclear weapons | Leave a comment

Patientfordeling

Nedenstående er en statistik over sygehuspatienter opdelt efter dominerende diagnose. Jeg fandt ud af, at jeg egentligt var irriteret over ikke at vide mere om dette. Tallene er fra 2007, og kommer fra Danmarks Statistik. Bemærk at “sygehuspatienter” ikke er lig “antal indlæggelser”: Antallet af indlæggelser i 2007 var næsten 1.2 millioner, svarende til ca. to per patient i gennemsnit (ikke fordi sådan et gennemsnit er meget værd – givet variationen i indlæggelsesgraden på tværs af patientgrupper giver det ikke meget mening at opgøre en sådan størrelse), hvoraf ca. 865.000 var akutte. Bemærk på den anden side også, at opgørelsen formentligt kun inkluderer patienter, der har været indlagt, og ikke eksempelvis patienter der følges eller behandles ambulant på et hospital (sagt på en anden måde inkluderer statistikken ikke alle hospitalspatienter, men den inkluderer alle, som har været hospitalsindlagt, og kun dem, der har været hospitalsindlagt): Eksempelvis er en stor andel af diagnosticerede diabetikere tilknyttet en endokrinologisk afdeling på et sygehus, og hvis alle disse patienter var med i opgørelsen, ville antallet af diabetikere i tabellen være langt højere end de ca. 5000, opgørelsen inkluderer.

patientfordeling

patientfordeling (tal)

May 26, 2009 Posted by | Data, Sundhed | Leave a comment

Interesting

In astrophysics and physical cosmology, Olbers’ paradox, is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. It is one of the pieces of evidence for a non-static universe such as the current Big Bang model. The argument is also referred to as the “dark night sky paradox” (see physical paradox).

Much more here. I love wikipedia!

I remember that this really puzzled me when I was a kid, that is, why the night sky looked the way it did (Olbers’ paradox actually isn’t a good place to start if you want to know that, but anyway…). I didn’t get why, if there was a lot of stars around in the sky, lighting up everything, then even if the universe was very large and the stars were far away, why was everything so dark at night? If there was a star in almost every direction I could see, then why wasn’t the sky much brigther? Also, if the universe was infinitely large (I had a really difficult time accepting that statement), then there would be an infinite number of stars too, rigth (no, that’s not right, see point a in the link. But I didn’t get that back then of course)? And if there was an infinite number of stars, they would light up the whole sky, not just bits and pieces here and there, rigth? Asking my parents didn’t really help… (I’m pretty sure it was during my “asking age” I wondered about this, that period of your life where you drive your parents insane by asking them so many questions that no human being can possibly answer all of them, but I’m also quite sure it took me a long time to pass that age, so that doesn’t really help me pinpoint the exact time).

Btw: If you were wondering, the number of stars visible with the naked eye at night-time at any given location on earth, given ideal viewing conditions, is in the neighbourhood of 3.000, as Asimov expressed it in his book Facts and Fancy (recommended): The faintest star that can be seen with the naked eye, under the best conditions, is of magnitude 6.5 and the number of stars that exist in the entire circuit of the skies that bright or brighter is just about 6000. That’s all. That’s the hard fact of it. Six thousand.

For comparison, it is estimated that the total number of stars in the observable universe is 7×10^22.

May 25, 2009 Posted by | Astronomy, cosmology, Random stuff | Leave a comment

Is it ok to assume the world is Cobb-Douglas?

From a new working paper by Shekhar Aiyar (IMF) and Carl-Johan Dalgaard (University of Copenhagen, DoE):

We use international data on relative factor shares and capital-output ratios to formulate a number of tests for the validity of the CD assumption. We find that the CD specification performs reasonably well for the purposes of cross-country productivity accounting.

You can download the whole paper at the link. The paper is a work in progress, so the “tables” and “figures” are still left blank in the text, even if they are included in the appendix, and that makes it a little bit more difficult to make sense of it all without too much scrolling. However I’ve only just skimmed the paper so far anyway, but I must admit that, for various reasons, I wasn’t all too surprised by the result.

Oh, if you don’t have a clue what the study is about, the Cobb-Douglas production function is the standard production function in economics, primarily because it’s a relatively simple functional form that has a lot of nice mathematical features, which makes it very easy to work with. Here’s wikipedia’s article on the Cobb-Douglas function.

Also, I’d just like to state for the record that insomnia sucks.

May 24, 2009 Posted by | Economics, Studies | Leave a comment

Quote of the day

Now what exactly is the HDI? The one-line explanation is that it gives “equal weights” to GDP per capita, life expectancy, and education. But it’s more complicated than that, because scores on each of the three measures are bounded between 0 and 1. This effectively means that a country of immortals with infinite per-capita GDP would get a score of .666 (lower than South Africa and Tajikistan) if its population were illiterate and never went to school.

Bryan Caplan. I liked this one too:

Scandinavia comes out on top according to the HDI because the HDI is basically a measure of how Scandinavian your country is.

May 23, 2009 Posted by | Quotes/aphorisms | Leave a comment

Quote of the day

“You’re wasting your time,” Doc Daneeka was forced to tell him.
“Can’t you ground someone who’s crazy?”
“Oh, sure. I have to. There’s a rule saying I have to ground anyone who’s crazy.”
“Then why don’t you ground me? I’m crazy. Ask Clevinger.”
“Clevinger? Where is Clevinger? You find Clevinger and I’ll ask him.”
“Then ask any of the others. They’ll tell you how crazy I am.”
“They’re crazy.”
“Then why don’t you ground them?”
“Why don’t they ask me to ground them?”
“Because they’re crazy, that’s why.”
“Of course they’re crazy,” Doc Daneeka replied. “I just told you they’re crazy, didn’t I? And you can’t let crazy people decide whether you’re crazy or not, can you?”
Yossarian looked at him soberly and tried another approach. “Is Orr crazy?”
“He sure is,” Doc Daneeka said.
“Can you ground him?”
“I sure can. But first he has to ask me. That’s part of the rule.”
“Then why doesn’t he ask you to?”
“Because he’s crazy,” Doc Daneeka said. “He has to be crazy to keep flying combat missions after all the close calls he’s had. Sure, I can ground Orr. But first he has to ask me to.”
“That’s all he has to do to be grounded?”
“That’s all. Let him ask me.”
“And then you can ground him?” Yossarian asked.
“No. Then I can’t ground him.”
“You mean there’s a catch?”
“Sure there’s a catch,” Doc Daneeka replied. “Catch-22. Anyone who want’s to get out of combat duty isn’t really crazy.”

There was only one catch and that was Catch-22, which specified that a concern for one’s own safety in the face of dangers that were real and immediate was the process of a rational mind. Orr was crazy and could be grounded. All he had to do was ask; and as soon as he did, he would no longer be crazy and would have to fly more missions. Orr would be crazy to fly more missions and sane if he didn’t, but if he was sane he had to fly them. If he flew them he was crazy and didn’t have to; but if he didn’t want to he was sane and had to. Yossarian was moved very deeply by the absolute simplicity of this clause of Catch-22 and let out a respectful whistle.
“That’s some catch, that Catch-22,” he observed.
“It’s the best there is,” Doc Daneeka agreed.

From Catch-22, by Joseph Heller, which I’m currently reading.

May 21, 2009 Posted by | Books, Quotes/aphorisms | Leave a comment

Promoting the unknown

(at this moment, all of the above have less than 3000 views. Also, #2 is a bit slow to load – give it a few secs to buffer or it will cough a bit in the beginning, which is something you really don’t wan’t it to do)

I wasn’t all too happy about the previous video I posted of the third piece, which is part of the reason why I chose to – well, sort of – double post it. I haven’t played much the last couple of months, but I am getting to the point where I can almost play it correct and in tempo. Of course it would take at least another month to have it ready for a public performance, but I feel no time pressure or need to get it perfected that fast – I guess that’s one of the many good things about only playing for yourself and never playing in public if you can avoid it (I have given only a handful of, more or less, public piano recitals during the last half decade, and only one of them included playing in front of some people I didn’t know. If anything that’s a good thing for classical music as a whole: If people wan’t to listen to classical music, by *** they really shouldn’t be listening to people like me, when recordings of people like Lipatti, Horowitz, Kempff and Gilels are readily available. This point I have had quite a bit of difficulty explaining to my parents).

May 21, 2009 Posted by | Music | Leave a comment

Ender’s Shadow

I’ve previously read Orson Scott Card’s Ender’s Game, the day before yesterday I read Ender’s Shadow. It’s not easy to know what to call it, even if Card does give it a try in his foreword of the book:

This book is, strictly speaking, not a sequel, because it begins about the where Ender’s Game begins, and also ends, very nearly, at the same place. In fact, it is another telling of the same tale, with many of the same characters and settings, only from the perspective of another character. It’s hard to know what to call it. A companion novel? A parallel novel? Perhaps a “parallax”, if I can move that scientific term into litterature.

Ender’s Game is about Ender Wiggin, Ender’s Shadow is about Bean. If you liked Ender’s Game, you’ll like Ender’s Shadow. If you liked Ender’s Shadow, you’ll like Ender’s Game: Both books can stand on their own and both complement the other. I liked both books very much.

May 19, 2009 Posted by | Books, science fiction | Leave a comment

A game

(Anonymous player) – US, 10 min. blitz, Petroff’s Defence:

1.e4 …e5
2.Nf3 …Nf6
3.Nxe5 …d6
4.Nf3 …Nxe4
5.d4 …d5
6.Bd3 …Bd6
7.0-0 …0-0
8.c4 …c6
9.Nc3 …Bf5
10.cxd5 …cxd5
11.Re1 …Nxc3
12.bxc3 …Bxd3
13.Qxd3
(I find no need to discuss the moves above in detail, it’s all theory so far)

chess1

13…Nc6
14.Bg5?!
(Rb1 is stronger) …Qd7
15.Re2 …Rfe8
16.Rae1 …Rxe2
17.Rxe2 …Re8
18.Kf1 …h6

chess2

19.Bh4 …Re6
20.Rxe6 …fxe6
(I wasn’t confortable with 20…Qxe6 on account of 21.Qb5. However, that move is not really a threat given black’s best response: 21…Qe4!. This neat fritz line explains nicely why 22.Qxb7 is suicide (no, I hadn’t found that myself, which is why I didn’t play 21…Qxe6): 22.Qxb7? 22…Qd3+!, 23.Ke1 (Kg1?? is mate) …Qxc3+, 24.Ke2…Qc2+, 25.Ke3 (Kf1…Qd3+, 26.Ke1…Bb4, 27.Qxb4…Nxb4) …Qe4+, 26.Kd2…Bb4+, 27.Kc1…Qd3, 28.Be7 (28.Qxc6??…Ba3++)…Bxe7 and black has now both lost a piece and is forced to give up the Queen to avoid mate)

21.Bg3 …Bxg3
22.hxg3 …Kf2
23.Ke2 …a6
24.a4 …Qd6
25.Qc2 …Qa3
(thinking about getting ready to shake hands by now, but I would like to give it at least 10 more moves. White has doubled pawns after all)

chess3

26.Nh4 …Ne7
27.f4 …Qd6
28.Kf3 …b5
29.axb5 …axb5

chess4

30.Qd3 …b4
31.cxb4 …Qxb4
32.f5 …Qe1
(It’s getting clear that it’s white that fights for the draw. However white should be able to hold this position with correct play. The position isn’t equal, but I doubt black has enough for a win with correct play by both players: Not a lot of pawns left on the board, they are all pretty close to each other and both Queens and knights left on the board – should probably be draw, even if white would have to fight a bit for it. However, white needn’t make many mistakes before the game is lost. Actually, he needed only make one: )

33.Kg4?? (the losing move)

chess5

33…fxe5!+
34.Nxf5 …Qe6
35.Kf4 …g5+
36.Kg4 …Kg6!

chess6

In this position the white knight is lost and white has no choice but to exchange queens after black’s check on f5. So here white resigned. A good game.

May 12, 2009 Posted by | Chess | Leave a comment

Brev till utlandet

A hilarious book by Eric Ericson consisting of letters sent by Mr. Ericson to various firms all over the world, all of them filled with downright insane ideas and proposals (the letters, that is, not the firms – or how is it again?), in which he pretends to have already made arrangements with the firms in question, thus more or less forcing the firms to reply to his crazy letters. The firms’ responses to the letters are included as well. Not a long book, but very, very funny. Below I have copied one example of the sort of correspondence the book is filled with:

Hello

First of all, I want to thank you so much for your invitation. I was both moved and surprised. I had not expected it in the least. I will arrive at your place on January 8 as agreed. I will bring approximately 200 small animals and about a hundred midsized and large animals. You should not pet the big animals. I would like you to order fodder for the animals right away. I have chartered a plane for me and the animals, as this is the most effective way to transport the animals. I have asked the airline to send the invoice to you directly. See you soon!

Eric Ericson
Mailbox 412
Birger Jarlsgatan 39
111 45 Stockoholm
Sweden

Sent to Spółdzielcza Grupa Bankowa, a Polish bank(!). The bank’s response:

Dear Sir,

Regarding to the mail, concerning your visit in Torun (Poland), I inform you, as following:
1. We don’t know you.
2. We have never invited you to Poland.
3. We only deal with banking business – not with animals.
4. We don’t expect you and especially your 300 animals.
5. We will not pay any invoice received from airline.

May 3, 2009 Posted by | Books, fun | 4 Comments