One of the weirder findings of the recent political science literature is that states which sign up to human rights treaties are _more_ likely, not less, to commit human rights abuses. This is hard to explain. In a new article for the _American Journal of Political Science_ (“ungated draft”:http://dss.ucsd.edu/~ylupu/Informative%20Power.pdf), Yonatan Lupu argues that this can probably be accounted for by selection effects. In other words, the finding reflects the fact that some states are more likely to sign up to human rights treaties than others, not the consequences of the treaty for subsequent state behavior. To show this, Lupu uses an interesting trick – he borrows the NOMINATE methodology that Americanists use to figure out the ideal points of Congressional legislators, and uses it to estimate the ideal points of states instead. The results suggest that human rights treaties do not cause states to commit more human rights violations; instead, states that commit more human rights violations are more likely to join human rights treaties. When selection artefacts are taken into account, treaties on torture and civil and political rights appear to have no consequences for human rights violations, but the Convention on the Elimination of All Forms of Discrimination against Women has a substantial impact on a wide variety of women’s rights.