Journal Article
Measures of state capacity

This study provides a systematic comparative analysis of seven common cross-national measures of state capacity by focusing on three measurement issues: convergent validity, interchangeability, and case-specifc disagreement. The author fnds that the convergent validity of the measures is high, but the interchangeability of the measures is low.

This means that even highly correlated measures of state capacity can lead to completely diferent statistical inferences. The cause of this puzzling fnding lies in strikingly large disagreements on some of the country scores. The author shows that these disagreements depend on two factors: diferences in underlying components and the level of state capacity.

Considering the fndings of this study, users of measures of state capacity must not assume that any highly correlated indicator is appropriate. They should instead look at what the indicators actually measure and ensure that a given defnition of state capacity matches the chosen indicator.