Emanuel Derman

Bad economic decisions have nonlinear effects

January 17, 2012

I have been reading an interesting post by Mark Thoma on how the Fed can prevent the next financial crisis, inspired by the release of minutes of Fed meetings in 2006.

Probably maybe

January 9, 2012

When I say that the probability of throwing 3 heads in succession is 1/8, that refers to the fact that if I toss three coins a large number of times, I believe that the number of times I get three simultaneous heads will asymptotically approach a ratio of 1/8. Each individual throw is of course governed by well understood mechanical laws, but the sequence of uncontrolled tiny effects at the start of and during each coin toss effectively produces a pseudo-random result.

To me you’re a wave, but to myself I’m sometimes a particle

January 4, 2012

In quantum mechanics — i.e. in the real world as we understand it today — matter can have two kinds of formerly apparently contradictory qualities.

All I want for New Year’s …

December 30, 2011

Lately it has become fashionable to disparage intuition in favor of careful statistical analysis.


December 29, 2011

I have been visiting family in Hong Kong for ten days, a place I’ve been to many times before for business, but always so briefly that I never really paid much attention to anything other than work and getting a run in.

Entranced by causality

December 28, 2011

Nassim Taleb highlighted economists’ and mankind’s ability to be fooled by randomness. Part of the reason economists and traders are likely to be fooled is because, underlying everything they do is the statistics of what is ultimately human behavior.

Paraphrasing Hayek

December 14, 2011

Self-schooled in finance and unschooled in economics, I was very glad to be sent a link to Hayek’s Nobel Prize acceptance lecture.  I’ve read around him, but not much in the original. One of these days …

Too Much Meta

December 12, 2011

I have a friend who, when you tell him about something bad that happened to you (“I fell and scraped my knee”) doesn’t address the problem at hand, but goes one level higher (“Yes, well that’s what happens when you run in the presence of a gravitational field”). I call that going meta, and I’m not crazy about it.

Rainer Werner Fassbinder on contagion

December 5, 2011

A couple of nights ago I watched “Lola,” one of the last movies made by the immensely prolific Rainer Werner Fassbinder, born in 1945 and dead at age 37. I’d seen a bunch of his movies in the Seventies, particularly liking “The Merchant of Four Seasons,” a sad sad movie of inevitability that reminded me a bit of Bresson’s “Au Hasard Balthasar.”

On self-destruction

December 1, 2011
I am thoroughly tired of Europe, America, Obama, the Republicans, banks central and peripheral, and everyone’s indignation about the above. And of my own indignation too. It’s affecting my quality of life. Part of this is owing to having worked much too hard and too obsessively over the past year, always trying to do one more thing to get it out of my in-tray. I got to the point where when I woke up in the middle of the night my mind began to race with thoughts of things that “needed” to be done and it became preferable to tackle them rather than try to go back to sleep, even though I knew it was a bad idea. And then, the other part is that the world news really is consistently disturbing and unfair. With this in mind, I have long admired/been jealous of people whom observe the Sabbath, whatever religion. My father often used to claim that the greatest historical contribution to humanity by the Jewish people was the idea of a day of rest, which appears right at the very start of Genesis. When you think about it, having a periodic day of rest isn’t obvious at all. I can’t say my father actually observed it most of the time, very rarely actually, but I see his point. It must be wonderful to rigorously observe one day as a retreat from the world of business, sport, competition, and effort, with intent and habit. I know a few people who do that (actually only one at this point, and he, I suspect, spends most days that way, so maybe it doesn’t count). One day, if I live long enough, I hope to try that myself. It’s quite clear that resting is very antithetical to life today. When I left New York for England in 1975, it was hard to do much of anything on a Sunday. Driving around the city was was a breeze. Shops were closed. And London too was a ghost town after 2pm on Saturdays. When I came back to NYC in 1977 Sunday shopping had begun, and department stores were open for a few short hours. Now Sunday traffic can be the worst of the week, in New York or in London. Not to mention the restless internet. In a way, the world has become aperiodic. You can do anything any time, denying the rule of the sun and the moon and the earth’s rotation. You can even have your periods aperiodically. One big part of this aperiodicity is an attempt to deny time and its working its weary way on you. But to be fair, whereas animals go into heat periodically, adult humans can mate any time, so maybe this tendency to aperiodicity was built into us by evolution. All science and discovery can be regarded as an attempt to short-circuit time by either figuring out the end of the story before Nature gets you there, or trying to prevent Nature from nudging you away from the beginning or the middle. In normal times, when one is very exhausted, either happily or sadly, sleep is a blessing to be embraced, and one yields gratefully to unconsciousness. Re true self-destruction: I have never been tempted. But, occasionally, maybe two or three times, I’ve been in situations where facing reality has been too unpleasant. Neither books nor movies nor people could distract me from what I didn’t want to face. Only sleep brought relief, in the form of a loss of identity and consciousness, a kind of temporary annihilation. Then you sleep, and if you can’t then you drink or take a sleeping pill until you can. That kind of urge for unconsciousness has always been  very occasional and temporary thing for me, Thank God, but by vast analytic continuation I can imagine some extreme form of that urge for unconsciousness and need to avoid oneself. That, I can imagine, would make permanent loss of consciousness a compulsive attraction. It wouldn’t be a plea for help, just such a strong desire for not being that one has to give in. It’s a kind of self-loathing, I would think. I wonder if there isn’t some more final version of this latter feeling, or even the former mere exhaustion, which would constitute the preconditions for a good and timely death.