New approach addresses state self-selection into treaties.

This paper outlines how international institutions shape state behavior, but states selectively join agreements. Ignoring this selection effect can mislead about causal impacts.

The authors propose combining ideal-point estimation with propensity-score matching to estimate treaty commitment probabilities and test hypotheses fairly.

They apply this method to analyze three key human rights treaties: the Convention on the Elimination of All Forms of Discrimination against Women, the Convention against Torture, and the International Covenant on Civil and Political Rights.

Results show that the CEDAW significantly improved women's rights protections in the USA. However, neither CAT nor ICCPR had notable effects on human rights overall.

This nuanced analysis clarifies the effectiveness of international treaties.