Brian over at Crooked Timber is thinking about Milton Friedman's defence from the charge that economic modelling is bunk, because empirical evidence shows that people rarely behave they way economic models assume they do.
I think Brian is on the right track by saying that Friedman is partly right to claim that models which generate accurate predictions are useful even when their foundations are known to be crap. However, I think identifying the objects of scientific theories as idealisations is the wrong way to go, and that he's underemphasising something that offers Friedman the possibility of a much stronger defence.
Back in the 19th century, there was some serious economist - I can't remember who, but I remember that he was not considered a crackpot - who thought that the business cycle followed the sunspot cycle. It appeared to fairly accurately predict the British business cycle for a fairly long period. So, he put forward a model that claimed that the sunspot cycle (which was a fairly new discovery at the time) affected agricultural productivity, and that this had a knock-on effect on the whole economy.
This idea was taken seriously, and viewed with some impartiality it isn't ridiculous. In the 19th century, agriculture employed a far larger portion of the population and represented far more of Britain's productivity than it does today. People also spent much more of their income on food and fuel than at the present. So, since they suspected that the sunspot cycle affected weather and climate, they thought it could affect agriculture. There was a plausible theory for how sunspots could cause recessions.
There was only one problem with the theory, and it was a big enough problem to kill that whole line of research. It's complete bollocks.
It turned out that, when they cracked open the books and did an empirical study, they couldn't find any sunspot related variation in agricultural productivity. If Brian's summary of Friedman's arguments are accurate, Friedman is saying that you can't hold the lack of relationship between sunspots and agriculture against an accurate model predicated on just such a relationship existing. It is my understanding that there was enough divergence between the sunspot cycle and the business cycle that any late 18th and early 19th century correlation between the two was almost certainly a coincidence, and that with an additional century and a half of business cycle data, there is no longer any evidence of a relationship between the two.
Brian does point out that a model has more than predictive value, it has explanatory value. Boyle's law - the example usually given of a useful predictive model known to be based on a false assumption - is useful in part because it has explanatory value. Boyle's model assumes that gas molecules in a container collide with the sides of the container, but never with each other. It's a fairly accurate model, because for a lot of kinds of work the difference between the Boyle model and more sophisticated models is quite small, and the calculus involved in Boyle's model is a lot easier.
However, even though Boyle's model includes a known false premise, it still correctly explains why gas pressure changes when volume changes. The basic explanatory value of the model is unaffected by the false premise. Gas pressure is still the force of gas molecules bouncing off the sides of containers, regardless of whether they bounce off each other. Boyle's model is useful not only because it makes fairly accurate predictions, but because it offers a substantial and correct insight into the phenomenon that it's modelling.
The sunspot model of the business cycle, in contrast, doesn't have any explanatory value if its underlying premises are false. Even though sunspots may accurately predict recessions, if sunspot activity has no effect on agriculture, you still know nothing about what causes recessions.
Friedman could have offered a much stronger defence of economic models based on false premises about human behaviour by taking this tack. He might have said, look, the model assumes that humans are rational optimisers and clearly they aren't. But, the real insight of current economic models is that macroeconomic phenomena are an emergent effect of individuals undertaking local, self-centred economic activities. [Okay, in 1953 Friedman would never have used the word "emergent", but there were synonyms he could have used.] Economic models show how individual activity can produce macroeconomic effects, and how macroeconomic policies affect individual behaviour, producing macroeconomic consequences. All this is still true even if humans are half-assed, incompetent utlity optimisers. The kinds of models we produce are just as insightful as Boyle's law, even though - just like Boyle's law - one or more of the premises is nonsense.
I don't think Friedman made that defence. Furthermore, I'm not making any claim about whether or not the kinds of economic models he advanced really are insightful or make accurate predictions.
Brian is right to think poorly of Friedman's claim that facts are irrelevant in the face of theory. (Friedman is starting to sound a bit post-modern to me.) But, I think both Friedman and Brian (and Michael Strevens, who he cites) could make a much better defence of economic models which contain false premises without getting involved in the idea that scientific theories are about idealisations.
Idealisations lead to instrumentalism, instrumentalism leads to behaviourism, and behaviourism leads to the dark side. I'd much rather deal with poorly predictive false theories that tell me something about my real objects of study than highly predictive false theories that tell me about idealised objects.
I regret to say that this is an inconsistently updated blog and will probably stay that way for the foreseeable future. I have a lot of R&D to get out in the next three months, and I need some staff that I don't have time to train or a budget to hire. But, I want to pick up where I left off a couple weeks ago. And I will. Soon. A big chunk of the post is written, and the most irritating thing is that I can see a bunch of other people posting on related topics while I'm working on it.
Until then, the French anti-anti-intelligence movement (I'm tempted to call them anti-idiotarian, but the word's been taken) is taking to the streets in the traditional leftist way, and I've posted on it over at AFOE.
For Professor Huntington, we here at Pedantry are preparing an old fashioned, downhome fisking, to begin tomorrow. It is truly unfortunate when a historian can't be bothered to do any historical research. Unlike Huntington, I do know a bit about immigration patterns in American history and I know especially about patterns of linguistic assimiliation. If I had brought my copy of Language in the USA with me to Belgium, I could do this tonight, but instead I will have to actually hunt down sources on the web. So, the post I was hoping to get up tomorrow will be delayed.
A fisking, for those who need to know, is a detailed rebuttal, usually on a line-by-line basis or at least with heavy quoting from the original text. It is named in honour of Robert Fisk, who was for a number of years the Middle East correspondent for London's The Independent newspaper and has frequently been subjected to exactly such treatment. Huntington's article is too long to actually dismantle on a clause-by-clause basis, so this will be a brief but vigorous fisking instead of the far more satisfying slow, tortuous, painful fisking which I believe a man of Samuel Huntington's stature deserves. This is, in large part, because I have work to do and other topics to get to.
For that reason, this will be a two-part post. I have Chinese class tonight, which means I can't start on the next part until tomorrow, where I will attempt to undermine Huntington's actual claims about Mexican immigration. Tomorrow, I'm going to primarily consider just two issues: Is Mexican immigration really different from past immigration? Does it pose a unique and novel threat to American national identity? That will take some writing that I haven't got time for today, so first, I intend to fisk Huntington's more basic ideas.
Also, it turns out that I did bring my copy of Language in the USA to Belgium. It is an invaluable resource for someone interested in language policy and ethno-linguistic identity issues in the US, in large part because it was first published in 1981 and has been out for print for some 15 years. Thus, it was written in a context where the civil rights movement was still within the adult memory of nearly all of its contributors and contains a language of empowerment and liberation almost completely absent from more recent language policy debates in the US. Also, it makes quite a bit more reference to the pre-1964 dark ages in American identity politics, and the bibliography is invaluable for the student of poorly conceived linguistic policies. Furthermore, I acquired my edition used, where it is full of very insightful hi-liter marks and notes in the margins.
I had mistakenly thought that Huntington was a historian rather than a political scientist, as Conrad Barwa notes. This may relieve Huntington of one dram of culpability, but that is hardly significant in comparison to the mass of material on the sociolinguistics and anthropology of America that he hasn't bothered to check.
Also, go take a look at Russell Arben Fox's review. If that's a defence, I'd hate to see how Russell responds to folks he doesn't like. I can be induced to agree that there is a real relationship between language and identity. Actually, it doesn't take much inducing, although I don't find it to be as essential as many people make it out to be. My only real difference on that count - isolated from everything else - is that I don't think identity should be essential to citizenship or the physical location of your residence. But, I'm going to talk about language tomorrow.
But, as an opener, let me direct you to something completely different:
Despite a desire to strike while the iron is hot, today's events in Spain have taken away my taste for pith. So, Huntington gets a day's reprieve.
I know that everyone in Spain is reporting that this must have been ETA, but this just makes more sense to me as Osama Bin Laden's contribution to the Committee to Relect the President. Terrorism is, above all else, a media strategy. I can see how 9/11 profits Al Qaeda as a media strategy and I can see how this would. I can't see how this profits a local nationalist movement like ETA.
I'm not saying this out of any sympathy for ETA - I'm vehemently against nationalism, but I'm very much pro-minority rights, so I have no ideological axe to grind either way and I don't know enough about Spain to have an informed opinion. It just makes less sense for an organisation in their position.
But that's all pure speculation. There's nothing to do but to wait to see what comes of it. Anyway, I imagine tomorrow I'll be back up to hacking pieces out of Huntington's metaphorical hide.
Sorry folks, I had expected to get up the rest on Huntington on the weekend, or failing that, today. Real life keeps interfering in extra-curricular activities. I'm not sure I'll be able to put anything up until Wednesday. In the mean time, go look at the coverage of recent events in Spain over at AFOE. Start here and keep rolling.
BTW - any readers out there who are experts in Salishan languages? I'm trying to find out which Salishan languages, if any, still have a reasonably healthy speaking community (e.g., spoken in most households in at least one place and has at least some speakers under the age of 10.) Ethnologue suggests that the answer is none.
This is part two of my fisking of Samuel Huntington's recent Foreign Policy article. Part 1 is here.
This still isn't complete. Hell, it isn't really edited - it's barely been spellchecked. I really need to write these things in advance and then edit them down, instead of putting it all on the page and then just posting it. This fisking is going to become a three-parter from the look of it. The good bit is next, because there I talk about America's long history of multilingualism and multiculturalism, and offer what I think is a novel theory to explain some recent phenomena in American identity politics.
There will probably be some fixes later.
Time is not my friend lately. The next bit ought to go up by the weekend, but I'm just doing a crappy job of sticking to my self-imposed deadlines.
Huntington's article in this month's Foreign Affairs, reveals a truly anachronistic streak - the trace of a vision of American history constructed in the service of an ideology thought to be all but dead among the educated classes. We've all been exposed to this skewed perspective at one time or another. In some schools, it's explicitly a part of the curriculum, but for the most part, it's an accepted element of the American narrative, something absorbed quite unconsciously from political speeches, news programmes and Fourth of July celebrations.
This vision begins with the statement that America is a land of immigration. This is not untrue, as far as it goes, but from there it turns into entirely different territory. It is a bit like the person who tells you that they aren't racist, but...
America is a land of immigration, or so goes the tale, a land of the free and the home of the brave. A shining light unto the world. Give me your tired, your poor, your huddled masses yearning to be free. From the beginning, America was an open country. It is a nation built by refugees from the perpetual conflicts that rage across less free lands, who came in search of peace, tolerance and freedom. Those who landed on its shores quickly abandoned the customs and prejudices of their old countries, adopting the ways of their free and tolerant neighbours. They worked hard to raise themselves up from the poverty they carried with them and, because America rewards hard work, quickly became prosperous. Now, America is a nation where their very roots have been lost, where religious and ethnic tolerance has reached heights unequalled in the world, where there is no entrenched class or hereditary privilege. Where anyone who wants to be truly American is held to be equal in the esteem of their fellow Americans.
The modern raconteur of this tale might make some mention of slavery and racial intolerance and how deeply regrettable it was, but they will assure you that that America is working to overcome those barriers. They might also recognise that there were - in the far past - a few incidents of ethnic conflict and that there have always been a few enclaves of the ignorant and bigoted, but not enough to really undermine the truth of their tale.
But - and this is almost always the next part - but now things are different. Now, there are people who come to America who don't want to be Americans.
It might be because their native cultures are too different, or it might be because America has grown soft, coddles immigrants, and tells them that it's okay if they don't find jobs, or learn English, or if they keep the values they came with. Or maybe it's because we let so many more of them into the country than in the old days, or maybe because the frontier is closed, so we can't just send them out west to build new farms. America is a post-industrial society now, and we have to compete with those immigrants for jobs.
Where it goes from there depends entirely on the political dispositions of the speaker. It might lead to the conclusion that America shouldn't let so many immigrants in, or that it should just let immigrants from certain places in, or that it ought to impose tough prerequisites on immigrants. Or, it might become a diatribe against welfare, liberals, identity politics, or some other scapegoat. And - and this more frequently true in intellectual circles on the right and the left alike than you would think - people might voice the quiet fear that those immigrants are really better educated, harder working and possibly inherently superior to us.
What I want people to understand is that the entire story - from its uplifting, life-affirming roots to its pessimistic, isolationist end - is complete poppycock.
As Cosma Shalizi notes, graduating from a top law school does not do much to equip you to judge scientific debates by itself. And remember, folks, these are the people in charge of America. Law has long been the most important trade and employment background of America's political leadership.
By all means go and follow the links from Cosma's post as well as the book review that started it all. It's also most illuminating to see the National Review show just how hostile they are to scientific enquiry when it doesn't fit the party line. I thought their anti-science carping was just limited to global warming, but then, I don't read them much.
I have noticed this trend in creationist scholarship to cite well-credentialed lawyers (and sometimes economists or physicists, but rarely any biologists) in arguments against evolution. I suspect they've taken a page from the tobacco and chemical industries. The anti-global warming people are really the trend-setters in using trial court methods to create public doubt in the absense of scientific doubt. It's a really disturbing approach to science policy.
I remember a James Hogan novel from back in the 70's that I read as a kid - I think it was Inherit the Stars - where he claimed that being a lawyer isn't very different from being a scientist. Unsurprisingly, Hogan is himself not big on evolution.
Being a scientist is utterly unlike being a lawyer. A trial lawyer is someone whose job is to either cast or undermine doubt about a particular claim without regard to its veracity, plausibility or evidential support. That is what the best defence means, and it explicitly means picking and choosing facts and arguments.
I take a dim view of credentialism, even on behalf of scientific ideas that I agree with. I think everyone ought to judge for themselves, even though - and sometimes because - they are likely to judge badly. But, I have to be suspicious when people whose trade often involves undermining or reinforcing other people's claims independently of their merits are found promoting a controversial idea outside their field of experitise.
This isn't lawyer-bashing as such. It's not even really trial lawyer-bashing - if I was on trial, I'd certainly expect my money to have some influence on the arguments my lawyer used. Most lawyers are not trial lawyers. The bulk of them, as far as I can tell, are employed on the basis of their expert knowledge of law and legal practice, a trade which is no less legitimate than being employed because of your expert knowledge of a foreign language. However, legal practice is overwhelmingly about categorisation and fiting things into particular categories. Science is also often about categorising things, but it is generally about creating categories to fit things, not the other way around.
If scientists are less likely to cherry-pick their data than lawyers are, it is because there are institutional mechanisms that punish them if they do. A trial lawyer can never be punished for casting events and people in the light most favourable to his or her client, and can be punished for failing to do so. The idea is that the opposing lawyer will do the same and somehow it will all work out. This is not exactly the way things work in the sciences. Once a trial (or the last appeal) ends, the case is decided. The winning lawyer can go home and chalk up one more victory. A scientific theory, on the other hand, has to produce continuing results and has to prove its value by repeated use indefinitely.
This is part three - my last word on Samuel Huntington's article for Foreign Policy. You can also read part one and part two. Also, let me recommend a related review of some of Pat Buchanan's work over at The Shamrockshire Eagle. It's worth it.
Huntington's fears about Mexican immigration are couched in a language which does more to make his point than anything he actually says. At every turn, Mexican immigration to the US is described in the terms of an invasion or a military advance. This sometimes leads him into contradictions. He believes that concentrations of Mexicans in the Southwest are a part of what is unprecedented about Mexican immigration, and yet the growing numbers of Mexicans and Mexican-Americans relocating to other territories are described as a "beachhead."
None of this is really new. It's all happened before with German, Irish and Italian immigration. No one speaks of the establishment of a "Jewish beachhead" in southern California in the 30's.
There is so much to criticise about Huntington's analysis that I am forced to limit myself to the most interesting problems.
The impact of Mexican immigration on the United States becomes evident when one imagines what would happen if Mexican immigration abruptly stopped. [...] Debates over the use of Spanish and whether English should be made the official language of state and national governments would subside. Bilingual education and the controversies it spawns would virtually disappear, as would controversies over welfare and other benefits for immigrants. [...] The inflow of immigrants would again become highly diverse, creating increased incentives for all immigrants to learn English and absorb U.S. culture. And most important of all, the possibility of a de facto split between a predominantly Spanish-speaking United States and an English-speaking United States would disappear, and with it, a major potential threat to the country's cultural and political integrity.
Official bilingualism is an issue driven almost exclusively by three communities: Hispanic-Americans whose roots predate 1960 and whose claims are drawn from the Treaty of Guadalupe-Hidalgo, Miami Cubans who control south Florida politics, and Puerto Ricans who think they are as American as everybody else. Mexican immigration is secondary to all those casuses. Bilingual education started out as an educational reform movement designed to improve English knowledge and school outcomes for immigrant children. It became legally established in a landmark court case in 1974 - Lau v. Nichols - in which the San Francisco public school district was held to have violated the 1964 Civil Rights Act by failing to offer a Chinese monolingual child ESL classes.
I'm quite bemused, but then, it's been a long week.