OVERVIEW

Modern political science fundamentally revolves around establishing whether there are causal relationships between important concepts. This is rarely straightforward and serves as the basis for almost all scientific controversies. How do we know, for example, if economic development causes democratization, or if democratization causes economic development, or both, or neither? To speak more generally, if we wish to know whether some X → Y, we need to cross four causal hurdles: (1) Is there a credible causal mechanism that connects X to Y? (2) Can we eliminate the possibility that Y causes X? (3) Is there covariation between X and Y? (4) Is there some Z related to both X and Y that makes the observed relationship between X and Y spurious? Many people, especially those in the media, make the mistake that crossing just the third causal hurdle – observing that X and Y covary – is tantamount to crossing all four. In short, finding a relationship is not the same as finding a causal relationship, and causality is what we care about as political scientists.

CAUSALITY AND EVERYDAY LANGUAGE

Like that of most sciences, the discipline of political science fundamentally revolves around evaluating causal claims. Our theories – which may be right or may be wrong – typically specify that some independent variable causes some dependent variable.