เปรียบเทียบวิธี

	Alliance Portfolio Similarity	Foreign Policy Similarity Score
สาขาวิชา	International Relations	International Relations
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1999	2011
ผู้ริเริ่ม	Bueno de Mesquita (Tau-b); Curtis Signorino & Jeffrey Ritter (S)	Foreign-policy-similarity literature (Signorino & Ritter; Voeten ideal points; Frank Häge chance correction)
ประเภท	Dyadic similarity index over alliance commitment profiles	Dyadic measurement of revealed foreign-policy agreement
แหล่งต้นตำรับ	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.	Häge, F. M. (2011). Choice or circumstance? Adjusting measures of foreign policy similarity for chance agreement. Political Analysis, 19(3), 287–305.
ชื่อเรียกอื่น	Alliance Portfolio Similarity Scores, S-Score of Alliance Similarity, Tau-b Alliance Similarity, Alliance Profile Similarity	Foreign Policy Similarity Measurement, UN Voting Affinity Score, Ideal Point Distance, State Preference Similarity
ที่เกี่ยวข้อง	3	3
สรุป	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.	A foreign-policy similarity score measures how alike two states' revealed foreign-policy positions are — most commonly from their votes in the UN General Assembly, but also from alliance portfolios or treaty positions. It is a workhorse measure of shared interests, affinity, and alignment in dyadic IR. Häge (2011) shows that naive agreement and the popular S-score can be inflated by chance agreement that arises because states differ in how often they take each position, and proposes chance-corrected indices (Scott's π, Cohen's κ) that better isolate genuine alignment.