Tuesday, July 25, 2006

Is Law a Complex Adaptive System?

The Simply Complex Law
By J.B. Ruhl
Post 5: Is Law a Complex Adaptive System?
July 25, 2006

In the previous set of posts (1-4) I laid out the basic framework of complexity theory and its lexicon for describing complex adaptive system (CAS) behavior. In this and the next few posts I set out the basis for applying complexity theory to law’s domain and the consequences this has for legal design.

I am going to assume most readers have no problem accepting that complexity theory provides a powerful analytical model for understanding many physical and biological systems, such as weather and ecosystems. Social scientists, however, are increasingly using complexity theory to understand how social organizations (corporations, the military, crime networks, families) behave at macroscopic scales. Some good background is found at the New England Complex Systems Institute, Australia’s Evolutionary Theories in Social Science site, and France’s Complexity in Social Sciences project(which wound down in 2003, but still has a very useful site).

So, why not law? Any lawyer is used to referring to “the legal system.” I got 10.8 million pages when I punched “the legal system” into Google today. Presumably the modifier, system, in that term of art means something to a lot of people. I propose it means the following:

The legal system (law for short) is a social organization comprised of a multitude of heterogenaeous, interacting agents (judges, lawyers, legislators, etc.) that respond to information inputs according to many rules. Law is focused on managing other social organizations (the economy, healthcare, crime, businesses). Frequently the intended effect of law is to influence how the target social organization treats a physical phenomenon (e.g., environmental law) or another social organization (e.g., employment law). Given that actors in the target and indirectly-influenced social organizations are likely to react to what law is doing to them, and that some of those actors are either actors in the legal system as well or can devise ways to influence actors in the legal system, law experiences feedback from its own behavior and co-evolution with other social (and physical) systems.

Now law is starting to look like a CAS. For example:

  • Can the legal system be understood through reductionist study of its agents?
  • Does anyone believe the path of the law is linear?
  • Go back in time, change some events (say, 9/11) and ask whether that would have made a difference for law’s evolution.
  • Examples of crossing critical thresholds? See Joseph Tainter’s 1988 book, The Collapse of Complex Societies, and Jared Diamond’s more recent and popularized book, Collapse.
  • The problem of conflicting constraints? Did someone say Patriot Act? Hard to have our cake and eat it too.

And so on. In the next few posts I am going to tease out these points in more detail and respond to questions, objections, and concerns I expect readers might have, such as whether complexity theory is just a metaphor for law (see comments to Post 2 of the series), and the role of norms.

Next: What should we expect if law is a complex adaptive system?


Anonymous Anonymous said...

I realize I'm jumping the gun a little, and I'm really looking forward to where this discussion is going, but here's two of the issues I think need to be tackled in treating the law as a complex adaptive system. First, the legal system has intelligent agents that control the behavior of the overall system in ways not found in other systems. As I understand it, there's a couple of things one might want to get out of studying the legal system as a complex adaptive system; one is to understand "emergent behavior" in the system that appears teleological but in fact is not consciously directed by any single agent or set of agents, like prices on the stock market. A second aim might be to understand sharp discontinuities or sudden catastrophes, which complex systems sometimes give rise to. Examples are the onset of turbulence in fluid flows (e.g., highway traffic), or the collapse of civilizations -- again, resulting from the activity of agents that are not attempting to produce the result that occurs. There's nothing complex about the occasional protests where a line of vehicles blocks all 4 lanes on a freeway, for example.

"The legal system" seems more like my highway protest example, however, and less like the stock market, in that at least some of the more important agents in the legal system (judges, legislators) often *do* act in ways intended to achieve the end result. For example, a judge may believe that it would be nice to allow this particular plaintiff to file a late brief, but may decide not to due to the effect that may have on the enforcement of deadlines generally, or on the demands on judges' time if the standards are relaxed. To the extent such agents have a large amount of control over the system, there's no puzzle of "emergent behavior" to explain, there's just behavior, and it adapts in the same way my behavior adapts when I find out that a plane flight has been cancelled. So I'm not sure that the means by which laws emerge and change is usefully studied as a complex system.

However, I agree that there are aspects of the legal system that more closely resemble a complex adaptive system, such as the behavior of ordinary citizens in following the law in non-legal settings, or even in following norms that are treated by agents as law-like. The difference there is that the role of decisionmakers such as judges and legislators is exogenous to their behavior, in the same way that regulators who try to influence the accuracy of the stock market are exogenous to the decisions of individual investors. I think studying norms as a complex adaptive system has promise -- in fact, I've tried it.

But that leads me to my second concern, which is that I'm not sure how you measure change in a legal system. In food webs, you can measure population densities; in the stock market, stock prices; which avalanches, you can measure the amount of material that flows downhill, and with turbulence, you can measure the speed of the flow; even with the rise and fall of civilizations, you can measure populations and territory over time. Measurements of adherence to laws or norms, however, seems incredibly difficult and subjective to me, and other than polling or self-assessment (both of which are problematic), I'm not sure how you achieve it. It may be possible to generate some simple simulations, as Randy Picker did in Simple Games in a Complex World a while back, but applying those simulations concretely to real-world examples may be difficult or impossible.

7/25/2006 4:58 PM  
Blogger Civis Americae said...

Wow! Fantastic contribution to the discussion. Thanks.

Although I do hope to get to all of these points in considerable detail eventually in the series, I certainly don't want to discourage comments like this along the way. So here are some brief preliminary thoughts:

1. You're absolutaely right that for social CASs there's this complication of agent intelligence (we hope so at least!). So, as you point out, the agents may try to "steer" the system, but also will experience emergent system behavior as a result, and that will have nothing to do with any normative agenda.

2. But I'm not sure what you mean in your second paragraph about "amount of control." No judge has that much control over macroscopic phenomena. Yet, even if judges as a whole "control" some aspect of law, why would that disqualify it from CAS behavior. The common law strikes me as ripe for study as a CAS, for example, and yet it is largely under the "control" of judges.

3. Measuring the legal system is a very interesting concept, and I'd love to have the time and money to do so. If I did, I would test whether the legal system exhibits power laws that seem pervasive in physical system CASs (see Per Bak's How Nature Works). One might measure, for example, the ratio of preamble to rule text in the Fed Reg over time; The number of new rules over time; the frequency of SCOTUS overruling decisions relative to total decisions, and the time lags thereof; the length of opinions in the FSupp over time, etc. My point is that the legal system produces all sorts of quantifiable output that could be used to measure what it is doing, whether it is changing in meaningful system ways, etc.

4. I do agree that compliance is very hard to measure (See Ruhl and Salzman, The Red Queen etc, at 91 Georgetown Law Review 757 (2003)), because it's hard to define the baseline. But, as we argue in the article, CAS theory has something to say about compliance in a heavily regulated state.

OK, I hate to cut this short, but I'd like to come back to all of these points in more detail in later posts. Thanks again, truly, for the comments. JBR

7/25/2006 8:00 PM  
Anonymous Anonymous said...

Re: 2, I agree no single judge or legislator has much control over the entire system; but collectively they may have quite a bit of control, such as a legislature. (Judges are a harder case, but I think they act in similar ways as a collective deliberative body.) Unlike the standard CAS examples, the collective behavior of legislators and judges is not spontaneous self-organization or an emergent property, but rather one of the intended results of the agents involved. If the stock market was run by a group on non-investors who gathered to deliberate on and then set the price of stocks, we wouldn't need complexity theory to explain how the prices move, although it may still have explanatory power with respect to how their beliefs change.

But I don't want to sidetrack the discussion, and I'm looking forward to your explanation of how the common law is a CAS. Perhaps that will clear things up.

7/26/2006 12:02 AM  
Blogger Civis Americae said...

Now I see the point you are making, and where we part ways. I don't agree that "the collective behavior of legislators and judges is not [attributable at all to] spontaneous self-organization or an emergent property, but rather one of the intended results of the agents involved." I agree that each of the agents in those systems has an intended result in mind, both for itself and for the collective, but I don't think what actually is the collective behavioral result is a 1-to-1 match with what was intended by "the collective." It's only in the abstract they we say "Congress intended..." and even at that we argue all day and night over what it intended. But this is an important question that deserves more discussion in a future post.

7/26/2006 10:17 AM  
Blogger Harvey said...

Here's a question for you. If law can be described as a CAS, what about the constitution? Should it be considered adaptive or fixed? If it is fixed, what does that mean for the future of this country? If it is adaptive, how far can one go in letting it adapt?

9/07/2011 4:55 PM  

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