Thursday, October 29, 2015

Microfoundations and causal powers

Image: Three Mile Island control room

There isn't a lot of cross-over between the microfoundations literature (Peter Hedstrom, Dissecting the Social: On the Principles of Analytical Sociology) and the causal-powers literature (Greco and Groff, Powers and Capacities in Philosophy: The New Aristotelianism). People who advocate the importance of microfoundations in the social sciences are usually looking for something like the individual-level mechanisms through which a higher-level pattern or entity comes about and persists. So the most natural relation is between microfoundations and mechanisms. And it is rare to find a powers theorist discussing the issue of microfoundations at all.

But it seems that this lack of intersection is the result of a clash of philosophical styles rather than an inherent logical or ontological fissure. The microfoundations group (e.g. Hedstrom, Elster, or myself in earlier versions) tends to be somewhat inclined towards an enlightened reductionism -- showing how higher level properties are produced by the workings of a lower level of phenomena. The causal powers group (e.g. Groff, Mumford and Anjum) are stoutly anti-reductionist; they seem to want to maintain that the powers of a thing are an irreducible and essential feature of the thing, not derivative from anything more fundamental.

But this opposition between the two research communities doesn't really seem compelling; it seems to derive from an abstract ontological preference rather than analytical arguments. So let's consider the question directly: how do the theories of microfoundations and causal powers relate to each other? Is it legitimate for microfoundations stories to invoke causal powers? And do causal-powers claims themselves require (or admit of) microfoundations?

The latter question seems to be the easier one. Whenever we attribute a causal power to a kind of stuff (conductivity to metal, violent volatility to a crowd, propensity to accidents to an organization), it is logical and appropriate to ask what it is about the substrate of the stuff that creates the power in question. What is it about the microstructure of metals that leads them to conduct electricity? What is it about crowds that leads them to be vulnerable to surges of violence? And what is it about certain kinds of organizations that leads them to be conducive to accidents like Three Mile Island or Bhopal? And when we answer these questions by detailing the microstructure of the stuff (metal, crowd, organization) and demonstrate how it is that this structure creates the durable power in question, then we have provided a microfoundation for the power. So powers admit of microfoundations. This response highlights the fact that the quest for microfoundations is really just an illustration of a pervasive explanatory strategy: investigate and measure the micro structure of the thing in question in order to discover why and how it behaves as it does.

Here is how I tried to sort out these relations in an earlier post on current thinking concerning the metaphysics of causality:

On this standpoint, powers are attributions we make to things when we don't know quite enough about their composition to work out the physics (or sociology) of the underlying mechanisms. They do attach to the entity or structure in question, surely enough; but they do so in virtue of the physical or sociological composition of the entity, not because of some inherent metaphysical property.

We might try to reconcile these two perspectives with a few simple ideas:

  • Entities and structures at a range of levels of being have causal powers: active capacities to influence other entities and structures.
  • Whenever we identify a causal power of a thing, it is always open to us to ask how this power is embodied; what it is about the inner constitution of the entity that gives it this power.
  • When we succeed in arriving at a good scientific answer to this question, we will have shown that the power in question is not irreducible; it is rather the consequence of a set of mechanisms set in play by the constitution of the entity.
So the discovery of a given causal power of a thing is not a metaphysical fundamental; it is rather an empirical scientific discovery that invites analysis into its underlying composition.

The harder question is whether there is any compelling reason for microfoundations theorists to think they need to refer to causal powers in their accounts. And this is where the powers theorists have a strong position: it is hard to make sense of the idea of a mechanism without referring to a real (perhaps reducible) causal power. This argument was made in an earlier post (link). Here is the key observation in that post:

My thesis of the mutual compatibility of powers and mechanisms goes along these lines. If we press down on a putative mechanisms explanation, we are led eventually to postulating a set of causal powers that provide the motive force of the postulated mechanisms. But equally, if we press down on the claim that a certain kind of entity has a specified causal power or disposition, we are led to hypotheses about what mechanisms are set in play be its constituents so as to bring about this disposition.

Begin with a causal mechanism story:
C => {x happens bringing about y, bringing about z, bringing about u, which is E} => E

How is it that the sub-links of this chain of mechanism pieces happen to work to bring about their consequent? We seem to have two choices: We can look to discover a further underlying mechanism; or we can postulate that the sub-link entity or structure has the power to bring about its consequent. So if we push downward within the terms of a mechanism explanation, one way to close the story is by postulating a causal power at some level.

So we might say that the relation among these three ideas goes something like this: A demand for microfoundations is a demand for the causal mechanisms at work within the substrate of the stuff in question. Mechanisms require provisional reference to causal powers; so microfoundations in turn require reference to causal powers. And finally, causal powers at a given level both demand and admit of provision of microfoundations to explain how they in turn work. So microfoundations theorists can't really dispense with the topic of causal powers, and powers theorists shouldn't dispense with microfoundations either. The diagram at the top illustrates this logic. It is turtles, all the way down.

1 comment:

Anonymous said...

Dan, Thanks for this. It is really helpful. I am working on a paper on the uses of models in political science drawing on Schelling and Cartwright and so have been wondering about the relation between models, mechanisms and capacities ... all in a modestly reductionist framework. This post really helps.

I hope you are well!
Jim Johnson