Using case studies in the social sciences: methods, inferences, purposes

Abstract

Despite fads and fashions in the academic culture, case-based reasoning has proved to be a persistent form of analysis in the social sciences, in the humanities, and even in moral thinking. Broadly understood, casebased reasoning locates the ultimate source of our epistemic and moral intuitions in the concreteness and idiosyncrasy of particulars. Even though they can be traced back to a common root, different traditions of reasoning with cases and of using case studies coexist in the academic landscape. This thesis focuses primarily on the use of case studies in the social sciences as an epistemic strategy to formulate, establish, and generalize causal hypotheses. A secondary goal is an investigation into the use of causal findings generated within and by means of case studies to inform policy making in the social realm.The thesis is organized in four chapters. In chapter 1, I characterize what can be regarded as two alternative views of case studies and the understanding of science in which they are embedded. The first approach flourished in the 1970s and looked at case studies as a special, and typically weaker, form of the experimental, statistical, or comparative methods. Since this approach tends to evaluate case studies by criteria belonging to other methodological traditions, it can be said to present a heteronomous paradigm. The second, alternative view, which was developed in the last decades, is taking shape gradually and is still far from being fully articulated. This approach strives for an understanding of case studies liberated from the narrow mindset that caricatures case studies as the method of last resort. In particular, it sees case studies as an autonomous epistemic genre (Morgan 2012).In chapter 2, I address internal validity in historical narratives. Historical narratives are case studies that aim to formulate and substantiate causal hypotheses by articulating descriptions of the sequences of events leading to the outcome of interest. They typically make use of process-tracing to draw causal inference, and often rely on the additional use of the methods of comparison. Despite the important role of historical narratives in the social sciences, how process-tracing operates in the narratives is still poorly understood. The debate on process-tracing in fact, even though it is growing thanks to a number of recent contributions, is still muddy and under-developed. In particular, there are no shared criteria to assess its epistemic contribution; moreover, the conditions proposed so far tend to tie the validity of the findings to the use of specific kinds of evidence and are thus unhelpful when this specific evidence is not available.I argue that the proposed conditions are unduly restrictive and fail to acknowledge the actual contributions process-tracing can offer to valid causal inference. I formulate new conditions to assess processtracing performance in cases in which the favourable evidential circumstances do not occur and existing criteria fail to apply.In chapter 3, I address the problem of generalizability. I provide an outline of what I define as the traditional view on external validity. This approach is conditioned by a statistical viewpoint on case study research (CSR) and reduces external validity to issues of mere representativeness. In so doing it leads the debate on the generalizability of case-study results to a dead end as it quickly dismisses external validity as the downside of CSR. At the same time, it suggests that CSR is comparatively stronger in providing internally valid results. On this ground this approach recommends the use of case studies when internal validity is the main research goal of interest, while turning to other methods when one pursues generalizations instead. This outcome is unfortunate because, as a matter of fact, case studies are often performed with the explicit or implicit purpose of drawing lessons from the studied case to be carried over to new contexts yet unstudied. …