Process Tracing

Conceptual Overview and Discussion

Process tracing effectively captures how an issue, situation, or pivotal event evolves, especially when the focus of the case is subject to the dynamics of change and time is an organizing variable. It is used to “unwrap” the causal links that connect independent variables and outcomes, by identifying the intervening causal processes, that is, the causal chain and causal mechanisms linking them. It also is able to consider responses of social actors in their context and to trace events from a static pre-causal point to the eventual outcome of interest. A process trace allows case researchers to account for equifinality, that is, a characteristic of open systems by which a given end state can be reached by many potential means. It offers the possibility of mapping out one or more potential causal trajectories that are consistent with the outcome and the evidence in a case. When applied to multiple cases, researchers are able to chart the potential complexity of differentiating alternative causal paths.

The issue of the starting point of the tracing process is highly contentious. Some researchers begin their process trace in moments of critical junctures, whereas others argue that only contingent events can trigger path-dependent processes. Whichever position one adopts, it is crucial for case researchers to theoretically justify their choice of the period under study. Although the starting point may be contested, the end point is easier to establish, because it is determined by the outcome of interest.

Why would researchers use process tracing? This methodology can encapsulate all of the intricacies and nuances leading to the outcome of a dependent variable more successfully than other theoretical frameworks. It is particularly suited to contexts in which decision making lies at the heart of the investigation (e.g., policy studies) or for grand-scale events (e.g., international relations). It can also explore the various stimuli (defined as independent variables) to which the different social actors react in relation to the internal and external conditions influencing the issue, situation, or pivotal event. Because it is based on a chronology, process tracing identifies important emergent influences that a more “snapshot” approach may miss and can control for the impact of omitted variables. The data used for this method are qualitative in nature and can include historical memoirs, interviews, press accounts, and archival documents. Multiple data streams are necessary, because rich and varied sources are required for process tracing. As well, the method is time intensive, frequently requiring years to collect the data and complete the analysis.

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