Once again, Daniel Little’s fascinating blog Understanding Society provides a gem on the relationship between microfoundations and explanation in the social sciences. All of this applies equally to many questions in political science (just replace “organization” with “state”).
My defense of meso-level causation is based on four ideas. First, the practice of sociologists justifies this claim, since sociologists do in fact make use of meso-meso claims. They often do not attempt to provide vertical explanations from circumstances of the actor to meso- and macro-level outcomes; instead, they often provide horizontal explanations that explain one set of meso and macro outcomes on the basis of the causal powers of another set of meso and macro conditions or structures. Second, sociology is a “special science” analogous to cognitive science, dependent on a set of causally linked entities at a lower level. Arguments offered for the relative explanatory autonomy of the higher-level theories are applicable to sociology as well. The basis for rejecting reductionism is well established here. Third, meso entities (organizations, institutions, normative systems) often have stable characteristics with regular behavioral consequences. This is illustrated with the example of organizations. Fourth, those entities must have microfoundations; we must be confident that there are individual behaviors at lower levels that support these macro characteristics. But it is legitimate to draw out the macro-level effects of the macro-circumstance under investigation, without tracing out the way that effect works in detail on the swarms of actors encompassed by the case. The requirement of microfoundations is not a requirement on explanation; it does not require that our explanations proceed through the microfoundational level. It is an ontological principle but not a methodological principle. Rather, it is a condition that must be satisfied on prima facie grounds, prior to offering the explanation. (I refer to this as the “weak” requirement of microfoundations; link.) In short, we are not obliged to trace out the struts of Coleman’s boat in order to provide a satisfactory macro- or meso-level explanation or mechanism.