Measuring Inter-State Relations Using Event Data

The strength of states’ bilateral relations is a central driver of important political outcomes, including armed conflict, trade, and foreign aid. Consequently, existing research has taken a keen interest in measuring affinity between states. Yet indicators of inter-state relations carry important limitations. Indicators measuring the formal dimension of state affinity, e.g., alliances, cannot capture short- to mid-term fluctuations in inter-state relations, whereas indicators capturing informal dimensions, e.g., shared voting patterns in the United Nations General Assembly, have so far relied on data sources limited to particular issues. This paper proposes a measurement strategy that addresses these limitations by relying on fine grained event data. Conceptually, we distinguish between two types of inter-state affinity: relational and relative. Relational affinity captures state affinities in relation to each other, whereas relative affinity captures the aggregate foreign policy preferences of states, relative to other states. Empirically, we construct indicators of relational and relative affinity using event data. Event data address the limitations of existing indicators by offering a way to capture nuanced changes in inter-state interactions across virtually all international issue areas. Our indicators provide scholars with new ways of identifying patterns, drivers, and effects of inter-state relations.