Alliance Portfolio Similarity
Alliance portfolio similarity measures how alike two states' overall patterns of alliance commitments are. Each state has a 'portfolio' — the profile of defense pacts, neutrality agreements, ententes, or no tie it holds with every other state — and the similarity of two portfolios is summarized in a single dyadic score. Signorino and Ritter (1999) showed that the long-dominant Kendall's tau-b measure is flawed for this purpose and introduced the S-score as a better-behaved alternative. These scores are a standard proxy for shared interests and have been used to operationalize utilities in expected-utility models of war.
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Sources
- Signorino, C. S., & Ritter, J. M. (1999). Tau-b or not Tau-b: Measuring the similarity of foreign policy positions. International Studies Quarterly, 43(1), 115–144. DOI: 10.1111/0020-8833.00113 ↗
How to cite this page
ScholarGate. (2026, June 22). Measuring Similarity of States' Alliance Portfolios. ScholarGate. https://scholargate.app/en/international-relations/alliance-portfolio-similarity
Which method?
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- Alliance Network AnalysisInternational Relations↔ compare
- Expected Utility Model of WarInternational Relations↔ compare
- Foreign Policy Similarity ScoreInternational Relations↔ compare