Thursday, September 30, 2010

Epistemic Deference and Epistemic Arguments for Conservatism I

A couple of months ago, there was a very interesting debate between Jim Manzi and others on the question of whether social science knowledge was sufficiently well established to warrant radical policy innovations. Manzi argued in a widely blogged article that the methodological limitations of the social sciences – in particular, the impossibility of appropriately measuring the counterfactuals of policy interventions through, for example, randomized experiments – implied that the findings of social science should normally not outweigh settled practice and even common sense” when we are thinking about changing existing practices or institutions. His critics argued, among other things, that social science can provide evidence that overturns such settled practices, since, after all, the status quo is typically the result of power struggles, not rational discussion; why should we give it more credence than the findings of social science, which emerge from a process that at least approximates rational debate?

We might put the general point thus: Manzi thinks that, where the complexity of social reality makes full scientific knowledge all but impossible, it makes better sense to give “epistemic deference” to settled practice; his critics think that the practices of “social science” as a whole (not necessarily a single random study) often have more “epistemic authority” than settled practice. This sort of division about the locus of epistemic authority also maps into a political division between “conservative” and “non-conservative” positions, with the “conservatives” granting some settled practices or institutions the bulk of epistemic authority, while the “non-conservative” position insists that some other person or institution, usually of more recent vintage, should be given greater epistemic deference than settled practice. Is there any way of adjudicating under what conditions are these positions likely to be right?

The conservative position is typically defended by arguments about the “limits of reason.” The classic statement is in Burke’s Reflections on the Revolution in France:
We are afraid to put men to live and trade each on his own private stock of reason, because we suspect that this stock in each man is small, and that the individuals would do better to avail themselves of the general bank and capital of nations and of ages. Many of our men of speculation, instead of exploding general prejudices, employ their sagacity to discover the latent wisdom which prevails in them. If they find what they seek, and they seldom fail, they think it more wise to continue the prejudice, with the reason involved, than to cast away the coat of prejudice and to leave nothing but the naked reason; because prejudice, with its reason, has a motive to give action to that reason, and an affection which will give it permanence. Prejudice is of ready application in the emergency; it previously engages the mind in a steady course of wisdom and virtue and does not leave the man hesitating in the moment of decision skeptical, puzzled, and unresolved. Prejudice renders a man's virtue his habit, and not a series of unconnected acts. Through just prejudice, his duty becomes a part of his nature.
As Burke puts it, the comparison makes sense; individual reason (or, for that matter, the individual social science study) is highly limited in its epistemic power in comparison to settled social practice. There is typically some reasonable basis for even highly perplexing social practices; and individual reason is likely to be highly misleading in many circumstances. Individually, we suffer from so many cognitive biases and defects that it is a wonder we get up in the morning; and even highly trained experts are often wrong, even in their own fields. (I read somewhere that most peer-reviewed research is eventually overturned). 

But as an argument the comparison is flawed; the relevant comparison should not be that between settled practice and individual reason, but between settled practice and some alternative social practice (e.g., the social practice of science, with its various self-correction mechanisms), or between settled practice and some other collective judgment (e.g., the collective judgment of an assembly or a market). Moreover, the “general bank and capital of ages” is often a “depreciating asset,” as Adrian Vermeule puts it, especially insofar as later people make no contributions to it. From this point of view, Burkean concerns about the limits of individual reason cut much less deeply; the question is about the relative “epistemic power” of different social practices, institutions, or processes. 

Yet I think there is often something to these “epistemic” arguments for conservatism. In later posts, I want to try to investigate under what conditions epistemic arguments for conservatism make sense. (This blog is mostly my scratch research notes, so read at your own risk). As a starting point, I think we might divide these arguments into three kinds: selection arguments (where the epistemic power of settled social practices comes from the operation of a selection filter that is not found in alternative social practices), computational arguments (where the epistemic power of settled social practices comes from the way in which they organize expertise and information), and resilience arguments (where settled social practices are found to be preferable to alternatives because they are adapted to a wide variety of circumstances, even if not optimal for any particular one of them). (Resilience arguments are really a subtype of selection arguments, but I want to think about them separately). More on each of these later.

[update 2:35: edited a few words for clarity].

Wednesday, September 29, 2010

Footnotes on things I've been reading: Adrian Vermeule's "Law and The Limits of Reason"

Adrian Vermeule, Law and the Limits of Reason (2009).

I read this book for somewhat hazy reasons; perhaps I found the title in a footnote of some paper and it seemed interesting, perhaps I ran across it by doing a search in our library catalog for something else and remembered that someone had once recommended  to me another one of Vermeule’s books. But at any rate, I’m glad I did read it, even though the main topic of the book is something that would normally not interest me very much.

The book is basically an attack on the “constitutional” common law, written primarily for (USA) legal scholars. As I reconstruct it, the basic problem is as follows. 200 and some years ago a few very smart people wrote a constitution for a country. (We’ll leave the name of the country blank, since the problem is pretty general; and I want to move away from any particularities of the American situation). Conditions at the time were very different from conditions today, however; so the problem arises as to whether, and how, to adapt the constitution to current circumstances. Should we change the constitution, and if so, who should change it?

At one extreme we can find the pure originalist position: the constitution should never be changed by anyone. This position is not as crazy as it may look at first glance. Assume that the constitution has survived intact for 200 years (and it has not been ignored during this period). It may then be that the very fact that the constitution has enabled the country to survive for 200 years implies that current constitutional rules are “resilient” – that is, they are broadly adapted to all kinds of circumstances, even if not optimal for any of them. They have been tested by time, with its varied challenges, and come out relatively well. Though different constitutional rules might have produced better outcomes at some points during those 200 years, no other set of rules we could design today would have plausibly produced a better outcome overall. We could perhaps temporarily achieve better outcomes (however defined) by adjusting the rules today, but then we could not be sure that the new rules would be optimal for other, as yet unforeseen circumstances, and we would have to adjust them again and again. And given some assumptions about the likelihood and costs of error, the relative wisdom of the framers versus our current wisdom, and our estimates of the rate of environmental change, it might be that it would never be worth our while to try to change these constitutional rules. We can think of this argument in terms of a trade-off between the benefits of adaptation to current circumstances and the benefits of resilience in changing conditions, given the limits of reason. If our estimates of the benefits of adaptation are low enough, of the resilience of current rules high enough, and of the uncertainty involved in formulating “perfect” rules for current circumstances high enough, perfect conservatism is entirely reasonable. (The earliest version of this argument I know of goes back to Plato’s Statesman, which I discuss extensively here. We also see something like this trade-off in nature: an organism can be too well adapted to its environment to survive drastic changes there. “Generalists” may thrive in changing circumstances, while “specialists” die since they cannot adapt quickly enough to these changes).

But suppose that we do not agree with the pure originalist position. (Few people do). The framers may have been very wise, but they did not foresee everything; and we may have a clearly good idea about how to improve existing constitutional rules (e.g., emancipating the slaves). But the problem still remains, since not every potential change is good: when should constitutional rules be changed, and by whom? The constitutional common lawyers argue that the constitution should (normally) not be changed by legislative assemblies or the “explicit” amendment mechanisms indicated in the constitution itself; instead, it should be changed gradually via the decisions of judges, just as proponents of the “regular” common law argue more generally that law should be changed not via legislative codification but rather through the gradual decisions of judges. Common-law constitutionalism thus tends to be associated with arguments for robust forms of judicial review and a general conservatism on matters of constitutional change, the key assumption being that the limits of reason are less binding on judges than on legislatures or the public, though still quite important.

Vermeule subjects this position to withering (though sometimes repetitive) scrutiny, arguing instead for a position that might be called “Benthamite” or “Thayerian” (as he labels it). On this view, legislatures face fewer epistemic constraints than courts in deciding to adapt constitutional rules to current circumstances, and hence courts should in general defer to them. (Note that this argument does not say much about incentives: it may be that legislatures face fewer epistemic constraints than judges in constitutional matters, but have worse incentives, and it is not clear which constraints would be “binding” in that situation). I am less interested in his ultimate conclusions, however, which are a bit too US-centric (including a plea for including at least one non-lawyer in the Supreme Court for interesting reasons having to do with the virtues of diversity in deliberative groups), than on his general approach to the problem of the limits of reason in politics and law, which is all about trying to figure out how "collective" mechanisms affect those limits.

Vermeule identifies two basic “epistemic” arguments for the constitutional common law position. On one view, the constitutional common law is better than the constitutional law created by legislatures or other explicit mechanisms because it combines the judgments of many judges over time to produce a judgment that is somehow better than the judgments of any individual judge (for reasons having to do with the Condorcet jury theorem, for example, though other mechanisms might be imagined). We can call this the “aggregation” argument. On the second view, which is associated with Hayek and his followers, the constitutional common law is better than the “explicit” constitutional law of legislatures because the process through which it is produced includes a selection “filter” that weeds out bad rules (the litigation and appeals process, for example) in ways that are not possible for explicitly created constitutional rules. We can call this the “selection” argument.

I am not going to discuss in detail all the considerations Vermeule deploys against these arguments. At any rate, it seems to me that the book is written very much like a lawyer’s brief: the constitutional common-law position is attacked from every possible perspective, some of which are less convincing than others. But a couple of points he makes are quite interesting. First, he argues that the “aggregation” arguments tend to suffer from a “nirvana” fallacy, where the benefits of aggregation are assumed to apply only to judge-made law. But in fact laws that are made by legislatures with many people should also benefit from considerations about aggregation (at least assuming equal incentives for information acquisition and sincere voting, which Vermeule discusses in some detail, though not always satisfactorily). And the kind of aggregation over time postulated by common-law constitutionalists may also suffer from informational cascades and epistemic “free-riding”: judges that defer to past decisions at a later time do not add any new information to the law, leaving the first few judges as the real legislators, for example. (“Epistemic free-riding” may also be a problem in legislatures, especially if the legislature is large, since then incentives for information acquisition are smaller. But this is more or less balanced – under some conditions, at least – by the greater epistemic diversity of legislatures, which should improve the quality of their decisions). Second, drawing on some interesting-looking work by Andrei Schleifer, he suggests that there is no plausible “selection” mechanism for the constitutional common law (though he is agnostic on the regular common law) that ensures bad rules get weeded out. Taken together, he is basically arguing that the limits of reason bind judges at least as much, if not more than, as they bind legislators; there are no special advantages to common-law constitutionalism over other forms of constitutionalism, and many apparent disadvantages.

Anyway, this is probably not a work for everyone (even if it is not particularly difficult to read); but I’m rather interested in “epistemic” arguments for conservatism, and this book offered a good overview of how Burkean arguments about the “wisdom of the past” and Hayekian arguments about the wisdom inherent in decentralized systems can be used or misused. 

Tuesday, September 07, 2010

On the flu, and a tale of two earthquakes

Apologies to my (very few) readers for the lack of blogging. Last week we got the flu - first my daughter, then me, then my wife - and we have been basically out of commission for 10 days (only now getting back to normal). Some of the flu viruses are wily antagonists, cleverly hijacking the body's cellular machinery to replicate themselves prolifically, and it seems to take a lot of the body's considerable resources to get rid of them (with much collateral damage in the form of large amounts of inflammatory cytokines, it has to be said).

In the meantime, there was a large earthquake in Christchurch, about 400km from where we live: 7.1 magnitude in the Richter scale. (It probably was what woke me up at 4:30am on Saturday morning, though I didn't consciously feel anything and in my state at the time it could have been anything). We don't know many people in Christchurch, but thankfully there seem to have been few casualties and no deaths as a direct result of the quake. Lots of damage, yes, but even then few building collapses. Yet compare this with the outcome of Haiti's January earthquake in Léogâne, measuring 7.0 magnitude in the Richter scale (a bit less than the Christchurch one, and also centered close to the surface): the estimates for deaths directly attributable to the quake range from 92,000 to 230,000 people; hundreds of thousands of people remain living in tent camps; the capital city remains shattered. Why the difference?

The time of the day the shaking happened may have made a difference (at least according to the useful summary in the wikipedia page on the Christchurch earthquake, which was up a day after the event). Yet I'm not sure I can see a clear causal story for how this is supposed to work: in Christchurch the earthquake happened when most people were sleeping inside buildings, in Haiti when most people were out and about; you would think the wee hours of the morning, when lots of people are basically unconscious under potentially falling objects, are the most dangerous time for an earthquake, but apparently not. Anybody care to enlighten me?

There is also the fact that most houses in New Zealand are timber framed, which means they bend a bit with the shaking, rather than quickly breaking or pancaking on top of their occupants, whereas most houses in Haiti are not, and that New Zealand has a strong building code that is actually enforced. But ultimately the factors that make the biggest difference seem to be the level of development and the quality of institutions of accountability. From the abstract of a recent (2005) paper by Matthew Kahn (gated):
Using a new data set on annual deaths from disasters in 73 nations from 1980 to 2002, this paper tests several hypotheses concerning natural-disaster mitigation. Though richer nations do not experience fewer natural disasters than poorer nations, richer nations do suffer less death from disaster. Economic development provides implicit insurance against nature's shocks. Democracies and nations with higher-quality institutions suffer less death from natural disaster. Because climate change is expected to increase the frequency of natural disasters such as floods, these results have implications for the incidence of global warming.
Higher levels of economic development and higher quality institutions make it possible to draft and enforce building codes in a relatively uncorrupt way, for example. And good institutions of accountability put the fear of their constituents into politicians, who may become very responsive to their needs in the aftermath of a disaster. Furthermore, in open societies information flows relatively freely and in generally useful ways: consider how Twitter was used to quickly aggregate information - and some misinformation - about the quake soon afterwards, particularly through the hashtag #eqnz; it's almost enough to make me rethink my principled avoidance of the service. Of course, this is itself only possible because the Internet backbone links and the electrical power supplies were not too badly damaged or were quickly repaired, and worked fine to begin with, something that economic development itself makes possible. It's another case of the unfairness of country borders: nature is harsher when you are born in a poor country (or in a non-democratic, not very accountable regime). By the same token, the best insurance against the destructiveness of nature seems to be economic development and democracy.