A nice example via Crescat Sententia of an issue I’ve mentioned before, namely, a case where the stylized facts lend themselves to an elegant bit of modeling that seems to analyze things very neatly, but the empirical details turn out to be much messier or a different kind of process altogether. Here it’s the debate about the Hijab in French schools. This is why fieldwork is important. The identification of mechanisms like sub-optimal conventions, failed co-ordination, tipping phenomena, self-fulfilling prophecies or auto-equilibrating systems are amongst the most useful and powerful tools in social science, but the number of phenomena they appear to explain is much larger than those they in fact explain. This can lead to odd consequences. For example, John Sutton’s little book Marshall’s Tendencies (which I didn’t read carefully enough when I picked it up) makes the point that we can be led to misapply standard models not just when the reality is much more complicated or otherwise difficult, but even when there’s a perfectly good alternative model available, just not the obvious one.
Reaction to my last few posts make me want to add disclaimers like “Look, this doesn’t mean formal modeling is unimportant or bad,” “Yes, yes, of course there are lots of very smart game theorists,” and “No, Libertarians, I am not talking about you, so please relax.”
And sorry to anyone who was expecting this post to be about the attractions of the other kind of model.
your last sentence was the most insincere sentiment ever expressed in a blog.
the most insincere sentiment ever expressed in a blog.
I dunno, that seems like a pretty high bar.
I vote for Laetitia Casta.
As a network security architect I design security protocols for the Web and Internet. I currently serve as editor for several active proposals.
The connection to the modelling question is that computer architecture frequently involves building models of the real world.
The big difference is that in computer science it is very hard to escape the brutal facts indefinitely. If your model is wrong you will usually end up being forced to admit it. Sometimes you can pretend you were right because no matter how bad something is the costs of change are far too great. But the pain is still there. The informed CompSci world knows that the ‘object persistence’ model developed ten to fifteen years ago is vastly superior to SQL but with close to a trillion dollars of sunk costs change is hard.
Ten years ago Bruce Schneier and myself both got seduced by the fact that cryptography could create unbreakable computer security protocols. We both eventually saw the light, Bruce wrote his appology in his book ‘Secrets and lies’. Being a protocol designer rather than a protocol analyst (in the security world you need both but analysts who break stuff tend to get more press), I was forced to face the fact a little earlier. When Bruce changed his mind he went way beyond my critique. Last month I was at a roundtable crisis meeting looking at a current security problem and suddenly everyone in the room realized that the model we had all being following was completely wrong, not just a bit flawed.
This could be crammed into the ‘Paradigm shift’ model, but thats not really what had happened. We all understood each other fine. We even showed our students slides with fine slogans like ‘Security is risk control (not risk elimination)’. But then we had gone off and built systems whose principal stated goals were to meet the needs of the military and principal unstated goal was to prevent Louis Freeh’s wiretap ambitions.
Because we thought we could build perfect security systems we tried. Predictably we ended up failling to build even good schemes half the time. One of the dirty secrets of the Internet security story is that the most widely used Internet protocol SSL was not very good at all when first proposed. In fact a catastrophic flaw was discovered fifteen minutes into the first public presentation, not a subtle error, a rookie mistake.
But in the end SSL did more than the perfection model ever did.
In the same post, the guys at crescat :
- discovers that this law, albeit french - like, y’know, statism, taxes and other assorted fascisms - is there because it helps people,
- and mentions the words “overreaction”, and “hysteria”.
… cute :-)
I hate to follow phill’s thoughtful, informative, evocative post. Many of us have tenderly husbanded elegant solutions that withered in the glare of hostile reality.
However, I wanted to mention the many plastic models I assembled as a teen: USS Constitution, HMS Victory, assorted knights, aircraft and antique pistols, all of which were eventually blown up with firecrackers in celebration of the Fourth of July. One moves at times from one seduction to the next.
Actually, it seems more like a game that involves both a coordination and collaboration dilemma. Such games usually have many uncooperative equilibria where intimidation and exploitation are common tactics in attempts to move to a more cooperative equilibrium in a decentralized manner. What is perhaps the more accurate characterization then is that it is an attempt to move from an uncooperative equilibrium to a cooperative one. The normative objection is that there is no obvious virtue to the cooperation (everyone opting to wear/not wear a headscarf).
And sorry to anyone who was expecting this post to be about the attractions of the other kind of model.
“All models are wrong. Some models are Yasmine.” :)
My name is Mondo, and I am a modeler.
The issues that Kieran raises are really at the heart of the craft of modeling, viewed as an exercise in “natural philosophy”. I do not wish to minimize their importance, but I think, in the end, the observations are not very deep, and can be summarized as follows: “reductionist models can be very useful, but they are often wrong.”
It is a pity that fundamentalists on both sides of the modeling question, in a wide variety of fields, fail to grasp the importance of this vital, yet rather banal, truth—thus making repeated statements like Kieran’s necessary. But aren’t we all already supposed to understand the unavoidable and never-ending necessity of the modeling-empiricism dialectic? I mean, aren’t all scientists and natural philosophers weaned on the works of those two great modelers, Ptolemy and Copernicus?
I do a fair amount of interdisciplinary work, meaning that I enjoy talking to people in fields that I don’t really know a lot about and working with them to develop explanatory/predictive models of phenomena that seem important. The entire process is fraught with perile at every step, including at the very beginning, because one can not even collect data without having at least an inchoate model guiding the experimental design. A skilled modeler is thus important even before the “real modeling” has begun.
Indeed, it is not even possible to make the distinction between the epistemological categories the Kieran takes as axiomatic, Things That a Model Appears to Explain and Things That a Model In Fact Explains, without a firm grasp on various alternative models.
Finally, let me say that there is nothing more common to a would-be modeler that to hear the statement that “your model is too simple” or “the actual situation is far more complicated”. It is so common, in fact, that applied mathematicians will quickly exchange knowing chuckles upon the mere mention of “the spherical horse model”. Of course, a modeler always needs to listen to this criticism, even though it is often made by a person who does not understand the modeling process, because it just might be correct. The skill of the modeler comes in filtering such criticisms to extract problems that are legitimate from those that merely appear to be legitimate!
Relevant perturbation analysis (via B&W).
I love game theory and I think it’s quite often applicable to the real world with only minimal changes - for instance, in the auction setting, where it’s pretty clear what people’s utilities are and it’s pretty clear what people’s strategies are.
But when you try using game theory to model other things - you really have to make sure you are modelling the right game. (And that’s before issues like bounded rationality, unclear preferences, and the like come into play.)
This is why fieldwork is important.
In this case that fieldwork would require understanding French. Something which the english speaking (and blogging) academia seems clearly incapable of.
I had to read the last sentence three times before I figured out what other sort of model there was.
I wish there would be a formal model for understandable english.
I was a bit disappointed by the ugly trick Peter Northrup uses to get his point across. No fieldwork or modeling would correct this.
Look at the development of the following phrases:
coerced by their fellow students
insults and even violence—mostly from their male classmates
the intimidation from the boys
intimidation, backed up by credible threats of violence
a boy who [] was preparing to engage in (presumably illegal) violence
a group of criminals
This transformation is used in this conclusion:
Expecting a law condemned by much of the international press and plausibly seen as targeting sacred observances to command respect among a group of criminals is a bit much.
[todo]
Insert remark about French models here.
[/todo]
À Gauche
Jeremy Alder
Amaravati
Anggarrgoon
Audhumlan Conspiracy
H.E. Baber
Philip Blosser
Paul Broderick
Matt Brown
Diana Buccafurni
Brandon Butler
Keith Burgess-Jackson
Certain Doubts
David Chalmers
Noam Chomsky
The Conservative Philosopher
Desert Landscapes
Denis Dutton
David Efird
Karl Elliott
David Estlund
Experimental Philosophy
Fake Barn County
Kai von Fintel
Russell Arben Fox
Garden of Forking Paths
Roger Gathman
Michael Green
Scott Hagaman
Helen Habermann
David Hildebrand
John Holbo
Christopher Grau
Jonathan Ichikawa
Tom Irish
Michelle Jenkins
Adam Kotsko
Barry Lam
Language Hat
Language Log
Christian Lee
Brian Leiter
Stephen Lenhart
Clayton Littlejohn
Roderick T. Long
Joshua Macy
Mad Grad
Jonathan Martin
Matthew McGrattan
Marc Moffett
Geoffrey Nunberg
Orange Philosophy
Philosophy Carnival
Philosophy, et cetera
Philosophy of Art
Douglas Portmore
Philosophy from the 617 (moribund)
Jeremy Pierce
Punishment Theory
Geoff Pynn
Timothy Quigley (moribund?)
Conor Roddy
Sappho's Breathing
Anders Schoubye
Wolfgang Schwartz
Scribo
Michael Sevel
Tom Stoneham (moribund)
Adam Swenson
Peter Suber
Eddie Thomas
Joe Ulatowski
Bruce Umbaugh
What is the name ...
Matt Weiner
Will Wilkinson
Jessica Wilson
Young Hegelian
Richard Zach
Psychology
Donyell Coleman
Deborah Frisch
Milt Rosenberg
Tom Stafford
Law
Ann Althouse
Stephen Bainbridge
Jack Balkin
Douglass A. Berman
Francesca Bignami
BlunkettWatch
Jack Bogdanski
Paul L. Caron
Conglomerate
Jeff Cooper
Disability Law
Displacement of Concepts
Wayne Eastman
Eric Fink
Victor Fleischer (on hiatus)
Peter Friedman
Michael Froomkin
Bernard Hibbitts
Walter Hutchens
InstaPundit
Andis Kaulins
Lawmeme
Edward Lee
Karl-Friedrich Lenz
Larry Lessig
Mirror of Justice
Eric Muller
Nathan Oman
Opinio Juris
John Palfrey
Ken Parish
Punishment Theory
Larry Ribstein
The Right Coast
D. Gordon Smith
Lawrence Solum
Peter Tillers
Transatlantic Assembly
Lawrence Velvel
David Wagner
Kim Weatherall
Yale Constitution Society
Tun Yin
History
Blogenspiel
Timothy Burke
Rebunk
Naomi Chana
Chapati Mystery
Cliopatria
Juan Cole
Cranky Professor
Greg Daly
James Davila
Sherman Dorn
Michael Drout
Frog in a Well
Frogs and Ravens
Early Modern Notes
Evan Garcia
George Mason History bloggers
Ghost in the Machine
Rebecca Goetz
Invisible Adjunct (inactive)
Jason Kuznicki
Konrad Mitchell Lawson
Danny Loss
Liberty and Power
Danny Loss
Ether MacAllum Stewart
Pam Mack
Heather Mathews
James Meadway
Medieval Studies
H.D. Miller
Caleb McDaniel
Marc Mulholland
Received Ideas
Renaissance Weblog
Nathaniel Robinson
Jacob Remes (moribund?)
Christopher Sheil
Red Ted
Time Travelling Is Easy
Brian Ulrich
Shana Worthen
Computers/media/communication
Lauren Andreacchi (moribund)
Eric Behrens
Joseph Bosco
Danah Boyd
David Brake
Collin Brooke
Maximilian Dornseif (moribund)
Jeff Erickson
Ed Felten
Lance Fortnow
Louise Ferguson
Anne Galloway
Jason Gallo
Josh Greenberg
Alex Halavais
Sariel Har-Peled
Tracy Kennedy
Tim Lambert
Liz Lawley
Michael O'Foghlu
Jose Luis Orihuela (moribund)
Alex Pang
Sebastian Paquet
Fernando Pereira
Pink Bunny of Battle
Ranting Professors
Jay Rosen
Ken Rufo
Douglas Rushkoff
Vika Safrin
Rob Schaap (Blogorrhoea)
Frank Schaap
Robert A. Stewart
Suresh Venkatasubramanian
Ray Trygstad
Jill Walker
Phil Windley
Siva Vaidahyanathan
Anthropology
Kerim Friedman
Alex Golub
Martijn de Koning
Nicholas Packwood
Geography
Stentor Danielson
Benjamin Heumann
Scott Whitlock
Education
Edward Bilodeau
Jenny D.
Richard Kahn
Progressive Teachers
Kelvin Thompson (defunct?)
Mark Byron
Business administration
Michael Watkins (moribund)
Literature, language, culture
Mike Arnzen
Brandon Barr
Michael Berube
The Blogora
Colin Brayton
John Bruce
Miriam Burstein
Chris Cagle
Jean Chu
Hans Coppens
Tyler Curtain
Cultural Revolution
Terry Dean
Joseph Duemer
Flaschenpost
Kathleen Fitzpatrick
Jonathan Goodwin
Rachael Groner
Alison Hale
Household Opera
Dennis Jerz
Jason Jones
Miriam Jones
Matthew Kirschenbaum
Steven Krause
Lilliputian Lilith
Catherine Liu
John Lovas
Gerald Lucas
Making Contact
Barry Mauer
Erin O'Connor
Print Culture
Clancy Ratcliff
Matthias Rip
A.G. Rud
Amardeep Singh
Steve Shaviro
Thanks ... Zombie
Vera Tobin
Chuck Tryon
University Diaries
Classics
Michael Hendry
David Meadows
Religion
AKM Adam
Ryan Overbey
Telford Work (moribund)
Library Science
Norma Bruce
Music
Kyle Gann
ionarts
Tim Rutherford-Johnson
Greg Sandow
Scott Spiegelberg
Biology/Medicine
Pradeep Atluri
Bloviator
Anthony Cox
Susan Ferrari (moribund)
Amy Greenwood
La Di Da
John M. Lynch
Charles Murtaugh (moribund)
Paul Z. Myers
Respectful of Otters
Josh Rosenau
Universal Acid
Amity Wilczek (moribund)
Theodore Wong (moribund)
Physics/Applied Physics
Trish Amuntrud
Sean Carroll
Jacques Distler
Stephen Hsu
Irascible Professor
Andrew Jaffe
Michael Nielsen
Chad Orzel
String Coffee Table
Math/Statistics
Dead Parrots
Andrew Gelman
Christopher Genovese
Moment, Linger on
Jason Rosenhouse
Vlorbik
Peter Woit
Complex Systems
Petter Holme
Luis Rocha
Cosma Shalizi
Bill Tozier
Chemistry
"Keneth Miles"
Engineering
Zack Amjal
Chris Hall
University Administration
Frank Admissions (moribund?)
Architecture/Urban development
City Comforts (urban planning)
Unfolio
Panchromatica
Earth Sciences
Our Take
Who Knows?
Bitch Ph.D.
Just Tenured
Playing School
Professor Goose
This Academic Life
Other sources of information
Arts and Letters Daily
Boston Review
Imprints
Political Theory Daily Review
Science and Technology Daily Review