Causal Inference, Agency, and the Problem of Inherent Endogeneity

Researchers often leverage exogenous variation in an independent variable in order to understand its effects, yet endogenous decision processes are central to many of the real-world phenomena we wish to understand. This review explores whether there are situations in which exogenous and endogenous variation in the same independent variable (e.g., a policy, treatment, or other action) may lead to different outcomes. I begin by laying out a conceptual framework for understanding these inherently endogenous causal processes, identifying three types of mechanisms through which they might arise and discussing their application to a range of empirical phenomena, such as institutional reform, community natural resource governance, and interstate conflict. I then suggest that learning about inherently endogenous causal processes requires researchers to place endogenous decision-making at the center of analysis rather than seeking to abstract away from it. I survey a range of methods (both positivist and nonpositivist) for doing so.